INVESTIGATION OF COAL QUALITY AT THE MUSHITHE COAL OCCURRENCE, SOUTPANSBERG COALFIELD, LIMPOPO PROVINCE, SOUTH AFRICA.pdf

SCHOOL OF ENVIRONMENTAL SCIENCES DEPARTMENT OF MINING AND
ENVIRONMENTAL GEOLOGY
INVESTIGATION OF COAL QUALITY AT THE MUSHITHE COAL OCCURRENCE,
SOUTPANSBERG COALFIELD, LIMPOPO PROVINCE, SOUTH AFRICA
BY
MPHANAMA THANGENI
STUDENT NUMBER – 15001079
A MINI-DISSERTATION SUBMITTED TO THE DEPARTMENT OF MINING AND
ENVIRONMENTAL GEOLOGY AT THE UNIVERSITY OF VENDA IN PARTIAL
FULFILMENT OF THE REQUIREMENTS OF THE DEGREE OF BACHELOR OF
EARTH SCIENCES IN MINING AND ENVIRONMENTAL GEOLOGY
SUPERVISOR: PROF J.S. OGOLA
DEPARTMENT OF MINING AND ENVIRONMENTAL GEOLOGY UNIVERSITY OF
VENDA
FEBRUARY 2019

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DECLARATION
I, Mphanama Thangeni, declare that this mini-dissertation is my own unaided work,
except where otherwise acknowledged. It is being submitted for the degree of
Bachelor of Earth Sciences in Mining and Environmental Geology at the University of
Venda, and it has not been submitted for any degree in any other University.
Signature Date
………………………. …………………………….
Supervisor Signature Date
………………………. …………………………….

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ACKNOWLEDGEMENTS
Firstly, I am grateful to the almighty God for giving me supremacy, strength, diligence
and knowledge to complete this project.
I wish to express my profound gratitude to my supervisor, Prof J.S. Ogola his
invaluable scientific guidance, persistence, and motivation throughout the research
work. This work would not have been possible without his immense contributions.
I sincerely express my profound gratitude to my mother Ms. T. Singo for always being
there for me and offering financial and moral support in the course of my studies.
I am entirely grateful to my mentor Mr S. Mukatuni for introducing me to coal geology,
which I absolutely had no previous knowledge of. This project could not have been
possible without his guidance, supervision and financial support.
I would also like to thank Mr. R.S. Ravele, Ms. P.G. Munyai and Mr M.E. Nengovhela
for providing transport to the study area and for doing this pro bono.
It is my wish to express my profound gratitude to Tshifularo V.D, Mangwaya L.T,
Maponya J.M, Singo N.C, Tshamano G.N, Maroge M and Mudau F, my fellow students
and friends for the invaluable role they played in giving me support, motivation, advice
and for keeping me in their prayers.
I would also like to give thanks to the University of Venda, Department of Mining and
Environmental Geology for providing all the necessary equipment and permitting me
to use their laboratory under direct supervision of Mr. C. Muzerengi.
I sincerely express my appreciation to Ramaano Sidogi, Phambano Mudzanani and
Vhutshilo Netshimbupfe for their assistance during fieldwork.
Last but not least, I would like to thank my family for their motivation, encouragement
and financial support throughout the course of this study.
God bless you all

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ABSTRACT
Globally, coal is a major source of primary energy needs, however its utilization is
associated with negative health and environmental impacts. South Africa is the
world’s 6th major producer of coal. The majority of South African coalfields have been
explored and exploited in detail, but Soutpansberg coalfield had previously received
less attention from researchers, resulting in inadequate information regarding the
geology and coal quality. Currently, there is no active colliery at the Soutpansberg
coalfield.
The aim of the study was to investigate the coal chemical and physical properties
affecting coal quality at the Mushithe coal occurrence which is located within the
Soutpansberg coalfield. Three coal seams of the Mushithe coal occurrence exposed
at the banks of Mbodi River were sampled by channel sampling method. Chemical
analysis involving proximate and ultimate analysis, bomb calorimetry, X-Ray
fluorescence spectrometry and petrographic analysis were conducted so as to
establish coal quality.
The Mushithe coal is hosted within alternating beds of shale. Mean vitrinite reflectance
values of Mushithe coal range from 0.738 -1.172%; hence the type of coal is ranked
between bituminous medium rank B and C based on the United Nations Economic
Commission for Europe (UNECE) coal classification. Most samples were
characterized by high ash (27.9%) and low sulphur content (0.24%). The maceral data
analysis indicated that the coal horizons are rich in vitrinite (77.77 vol%), with low
inertinite (22.23 vol%) and no liptinite content. On average, calorific value of Mushithe
coal is 14.26 MJ/kg, thus classified below grade D on the Steyn and Minnitt (2010)
coal classification. Coal contained clay, pyrite, quartz and carbonate minerals, and the
dominating oxides were SiO2 (24.16 wt%) and Al2O3 (10.43wt%). There was a strong
statistical correlation between the other major oxides with SiO2 and Al2O3 indicating a
common source for these oxides. Potentially hazardous trace elements that were
found in the Mushithe coal includes As, Cr, Co, Ni, Pb, Th and U
Keywords: Mushithe coal occurrence, Soutpansberg coalfield, Coal quality, Proximate
analysis and Calorific value.

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TABLE OF CONTENT
DECLARATION .......................................................................................................... i
ACKNOWLEDGEMENTS.......................................................................................... ii
ABSTRACT .............................................................................................................. iii
TABLE OF CONTENT.............................................................................................. iv
LIST OF FIGURES................................................................................................... vii
LIST OF TABLES ..................................................................................................... ix
CHAPTER 1: INTRODUCTION ................................................................................. 1
1.1 Background .......................................................................................................... 1
1.2 Study Area............................................................................................................ 2
1.2.1 Location............................................................................................................. 2
1.2.2 Climate .............................................................................................................. 3
1.2.3 Topography and Drainage................................................................................. 3
1.2.4 Soil and Vegetation ........................................................................................... 3
1.3 Problem Statement............................................................................................... 3
1.4 Justification........................................................................................................... 4
1.5 Research Questions............................................................................................. 4
1.6 Objectives............................................................................................................. 4
CHAPTER 2: LITERATURE REVIEW....................................................................... 5
2.1 Coal In South Africa ............................................................................................. 5
2.1.1 Overview of Prominent South African Coalfields............................................... 6

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2.2 Geology of The Mushithe Coal Occurrence ......................................................... 8
2.2.1 Limpopo Mobile Belt.......................................................................................... 8
2.2.2 Soutpansberg Group....................................................................................... 10
2.2.3 Karoo Supergroup........................................................................................... 13
2.3 Coal Overview.................................................................................................... 15
2.3.1 Coal Formation................................................................................................ 15
2.3.2 Macerals.......................................................................................................... 16
2.3.3 Coal Mineralogy .............................................................................................. 18
CHAPTER 3: MATERIALS AND METHODS .......................................................... 20
3.1 Preliminary Work................................................................................................ 21
3.3.1 Desktop Study................................................................................................. 21
3.1.2 Reconnaissance Survey.................................................................................. 21
3.2 Fieldwork............................................................................................................ 21
3.2.1 Coal Sampling................................................................................................. 22
3.3 Laboratory Work................................................................................................. 23
CHAPTER 4: RESULTS AND DISCUSSION .......................................................... 30
4.1 Coalbed Stratigraphy.......................................................................................... 30
4.2 Petrographic Data Analysis ................................................................................ 32
4.3 Coal Data Analysis And Classification................................................................ 39
4.4 Whole Rock Geochemistry Data Analysis .......................................................... 44
CHAPTER 5: CONCLUSIONS AND RECOMMENDATIONS ................................. 57

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5.2 Conclusions........................................................................................................ 57
5.3 Recommendations ............................................................................................. 58
REFERENCES......................................................................................................... 59

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LIST OF FIGURES
Figure 1.1: Locality map of the study area…………………………………………………2
Figure 2.1: Map showing coalfields of South Africa……………………………………...5
Figure 2.2: Map illustrating metallurgical coal trends of the Soutpansberg coalfield….8
Figure 2.3: Simplified geological map of the Limpopo Mobile belt……………………10
Figure 2.4: Illustrative map showing the distribution of geological formations within the
Soutpansberg group……………………………………………………………………….11
Figure 2.5: Stratigraphy and correlation of the Main Karoo Basin and the Soutpansberg
basin………………………………………………………………………………….……..14
Figure 3.1: Flow chart illustrating methods and procedures applied in the study……..20
Figure 3.2: Coalbed image showing three profiles (A-C) delineated for channel
sampling method…………………………………………………………………………...22
Figure 3.3: Sample preparation: (A) sample crushing with a jaw crusher, (B) Vacutec
970 drying oven for removing moisture in samples, (C) Retsch RS 200 milling machine
for pulverizing samples, (D) palletizing milled samples, (E) pressing pellets with a
hydraulic press and (F) X-Ray Fluorescence Spectrometer for analysing elemental
composition of samples……………………………………………………………………24
Figure 4.1: Coalbed stratigraphy of the Mushithe coal occurrence……………………31
Figure 4.2: Major maceral groups present in coal……….………………………………33
Figure 4.3: Micrographs showing identified Vitrinite, Inertinite macerals and alteration
minerals, taken at a magnification of x500, under white reflected light using an oil
immersion lens for Sample Coal 1B………………………………………………………34
Figure 4.4: Micrographs showing identified Vitrinite, and Inertinite macerals, taken at
a magnification of x500, under white reflected light using an oil immersion lens for
Sample Coal 2A……………………………………………………………………………35

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Figure 4.5: Micrographs showing identified vitrinite, Inertinite macerals and alteration
immersion lens for Sample Coal 3C………………………………………………………36
Figure 4.6: Mineral matter content associated with coal………………………………..38
Figure 4.7: Comparison between inherent moisture, ash content, volatile matter and
fixed carbon in coal…………………………………………………………………………40
Figure 4.8: Comparison of carbon, hydrogen, sulphur and oxygen content in coal…..42
Figure 4.9: Comparison of heating values of coal between Mushithe coal occurrence,
Vele, Makhado and Tshikondeni collieries……………………………………………….43
Figure 4.10: Comparison of major oxides associated with coal….……………………48
Figure 4.11: Comparison of major oxides associated with shale ………….………….49
Figure 4.12: Comparison of potentially hazardous air pollutants associated with
coal…………………………………………………………………………..…………….. 56
Figure 4.13: Comparison of potentially hazardous air pollutants associated with
shale…………………………………………………………………………………………56

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LIST OF TABLES
Table 2.1: Macerals and maceral group description of coal ……………………………16
Table 3.1: classification of coal based on caloric value and proximate analysis
parameters as used in South Africa………………………………………………………29
Table 4.1: Maceral group data analysis……………… ……….…………………………32
Table 4.2: Vitrinite reflectance data analysis…………………………………………….37
Table 4.3: Mineral matter data analysis…………………………………………………..38
Table 4.4: Proximate analysis of Mushithe coal samples………………………………40
Table 4.5: Elemental composition analysis of Mushithe coal………………………….41
Table 4.6: The heating values of Mushithe coal samples……………………………….43
Table 4.7: X-ray Fluorescence Spectrometry analysis data for major oxides associated
with coal (wt %)……………………………………………………………………………..48
Table 4.8: X-ray Fluorescence Spectrometry analysis data for major oxides associated
with shale (wt %)……………………………………………………………………………47
Table 4.9: Correlation coefficient matrix for major elements in coal…………………...49
Table 4.10: X-ray Fluorescence Spectrometry analysis data for trace elements
associated with coal (ppm)….…………………………………………………………….52
Table 4.11: X-ray Fluorescence Spectrometry analysis data for trace elements
associated with shale (ppm)………………………………………………..……………..54

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CHAPTER 1: INTRODUCTION
1.1Background
Coal has dominated the energy supply sector in South Africa since 1880. Ninety one
per cent of electricity generated in South Africa is based on coal combustion in steam-
turbine driven power plants, and this is unlikely to change significantly in the next
decade due to the relative lack of suitable alternatives to coal as an energy source
(IEA, 2014). All 19 South African coalfields are found within the rocks of the Main
Karoo Basin and distributed across five provinces (Hancox and Gotz, 2014; Van der
Walt, 2012). Prominent coalfields in South Africa are Witbank, Highveld, Ermelo and
Waterberg coalfields. Coal depletion in prominent coalfields shifted attention to the
exploration of coal in less prominent coalfields such as the Soutpansberg coalfield as
it is becoming increasingly important to find other coalfields with economically
exploitable resources (Van Heerden, 2004).
Soutpansberg coalfield is sometimes referred to as the ‘’forgotten basin’’ because it is
mostly underdeveloped and had previously received less attention from researchers
(Sparrow, 2012). Many coalfields in South Africa have been explored in detail and
exploited, while coalfields in the northern part of the country including Soutpansberg
Coalfield have until recently received less attention as they are known to have
relatively less coal compared to other South African coalfields (Hancox and Gotz,
2014). Mushithe coal occurrence has received much less attention from researchers
as compared to other coal occurrences in Tshikondeni area which had previously
hosted the Tshikondeni coal mine.
In the past, the only considerations given to coal quality was whether the coal can be
easily burned to produce the desired heat energy without producing too much ash.
However, current studies on coal should cover all aspects of the origin, burial history,
and composition so as to understand the factors involved in determining coal quality
(Schweinfurth, 2009). Negative environmental effects of coal combustion may be
reduced with a better understanding of coal quality (Finkelman, 1998).
Detailed exploration of the Soutpansberg coalfield was done by ISCOR in 1978, but
other areas were ignored in favour of the Tshikondeni project which is the only area

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where mining previously took place within the Soutpansberg coalfield (Hancox and
Gotz, 2014). Currently, there is inadequate information regarding the coal quality at
the Mushithe coal occurrence.
This study was focused on the Mushithe coal occurrence, specifically on the coal
quality including its chemical and physical characterisation.
1.2 Study Area
1.2.1 Location
The study area is located at Mushithe village, Limpopo Province, South Africa and
within the Soutpansberg Coalfield. Mushithe is approximately 80 km North-East of
Thohoyandou town, approximately 130 km South-East of Musina town and
approximately 16 km west of Tshikondeni coal mine (Fig. 1.1). The study area lies
within latitude 22° 31’ 4” S and longitude 30° 47’ 48” E.
Figure 1.1: Locality map of the study area (Esri, 2018).

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1.2.2 Climate
Mushithe is situated in a summer rainfall region. The annual rainfall of this region can
reach up to 2 000 mm. Most rainfall occurs between the months of October and March.
The area receives the least amount of rainfall between the months of April and
September, and the most during December and February. Daily temperatures in the
area range from about 20°C to 40°C with an average range of between 17°C and 27°C
in summer and 7°C to 20°C in winter (Netshitungulu, 2001).
1.2.3 Topography and Drainage
The topography of the Mushithe area is controlled by the underlying geology. Mushithe
is characterised by alternating low hills and open hills that geographically strike in an
East-West direction across the area. The area has an inclination slope of 1:20 towards
mountains to the south, steepening to 1:30 up the mountain face. The Mushithe area's
surface water drains to the non-perennial Mbodi River. The Mbodi River is a tributary
of the Mutale River which is a perennial river. The Mutale River feeds the Luvuvhu
River which is a tributary of Limpopo River.
1.2.4 Soil and Vegetation
The study area is generally dominated by sandy loam soils as well as rocky soils. The
area is composed of low to medium potential arable land. The vegetation of the study
area is categorised as Tropical Bush and Savannah, with Musina Mopane Bushveld
and Soutpansberg Mountain Bushveld as the primary vegetation types. The
representative vegetation is dominated by medium to high shrub savannah with
dispersed trees.
1.3 Problem Statement
Most of the work done on the Soutpansberg Coalfield regarding coal quality are
generalisations of the entire Soutpansberg Coalfield or only partnering to the
Tshikondeni mine. There are limited studies relating to Mushithe coal occurrence. As
a result, no detailed study has been undertaken to determine the coal quality.

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1.4Justification
Studying the chemical characteristics of coal at Mushithe occurrence will be useful in
understanding the intrinsic characteristics of coal and coal rank. Results of the study
could, therefore, be used in making decisions on whether the coal is worth mining or
not.
The proposed study will also contribute knowledge on the geology of Mushithe coal
occurrence and will complement future studies on coal quality and coal use in the area.
This study will serve as a guide for the exploitation of coal in the Soutpansberg
coalfield with a direct implication on the Mushithe coal occurrence.
1.5Research Questions
• What is the rank of coal at the Mushithe coal occurrence?
• What is the maceral composition of coal?
• What is the degree of coal purity?
• What is the chemical composition of coal?
• What is the energy content of coal?
1.6Objectives
The main objective of the study was to characterise the physical and chemical
properties of coal at Mushithe coal occurrence.
Specific objectives were to:
• Determine the maceral composition and rank of coal using petrographic study;
• Determine the degree of coal purity using proximate analysis;
• Conduct quantitative analysis of various elements in coal using ultimate
analysis and x-ray fluorescence spectrometry; and
• Determine the calorific value of coal using bomb calorimetry.

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CHAPTER 2: LITERATURE REVIEW
2.1 Coal In South Africa
Based on sedimentation, quality, origin, formation and distribution of coal, 19 coalfields
are generally recognised in South Africa (Fig. 2.1) (Hancox, 2016). Based on
variations in sedimentation, origin, formation, distribution and quality of the coals Most
coal in South Africa were formed during the Permian period (Mphaphuli, 2017;
Hancox, 2016). According to Mphaphuli (2017), majority of coal in South Africa are
bituminous with some anthracites present in KwaZulu Natal coalfields. South African
coal range in age from Early Permian to Late Triassic, with the majority being of
Permian age, comparable to other Gondwanan coals in Sub-Saharan Africa, Australia,
and South America (Hancox and Gotz, 2014). South African coal is used for power
generation, synthetic fuel production and for metallurgical purposes (Hancox, 2016).
Coal in South Africa is preserved within the rocks of the Karoo Supergroup.
Figure 2.1: Map showing coalfields of South Africa (Hancox, 2016).

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2.1.1 Overview of Prominent South African Coalfields
Witbank Coalfield
Witbank coalfield is situated east of Johannesburg in Mpumalanga province (Pinetown
et al., 2007). Witbank Coalfield extends roughly 25°30′ S to 26°30′ S by 28°30′ E to
30°00′ E covering an area over 568,000 ha (Hancox and Gotz, 2014). According to
Hancox (2016), the Witbank coalfield has over 125 years of commercial exploration
and it supplies more than 50% of South Africa’s saleable coal. Coal seams in the
Witbank Coalfield are normally flat lying, with the regional dip ranging from 1° to 3°.
Five individual coal seams are generally recognised with the No. 2, 4 and 5 seams
being the most economically significant (Hancox, 2016). The Witbank coalfield
produces both thermal and metallurgical coal for local and international markets and
hosts some of South Africa’s major coal-fired power stations such as Arnot, Komati,
Kendal and Duvha (Hancox and Gotz, 2014).
Waterberg Coalfield
Waterberg coalfield is situated about 400 km northwest of Johannesburg in the
Limpopo province, immediately north of the Waterberg mountain ranges (Hancox and
Gotz, 2014). Coal seams in the Waterberg coalfield are confined within the Ecca
Group, Vryheid Formation and the Volksrust Formation which is known as the
Grootegeluk Formation in the Waterberg region (Cairncross, 2001). The coalfield has
eleven coal zones, four of which are found in the Vryheid Formation, and the remaining
seven are found in the Grootegeluk Formation. Waterberg Coalfield is considered to
be South Africa’s last major coalfield as it contains about 40% to 50% of the country’s
remaining coal resources. The coalfield hosts the Eskom’s 3,990 Megawatts Matimba
Power Station which is the world largest direct dry cooling power station (Hancox,
2016).
Highveld Coalfield
Highveld coalfield is situated in Mpumalanga province, about 200 km south-east of
Pretoria, south of Witbank Coalfield and covers about 7000 km2 (Wagner and
Hlatshwayo, 2005). The Highveld coalfield is similar to the Witbank coalfield in terms

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of general stratigraphy and they are separated by the Smithfield Ridge (Hancox and
Gotz, 2014). Coal deposits in the Highveld coalfield are hosted within the Vryheid
Formation of the mid-Permian Ecca Group of the Karoo Supergroup (Wagner and
Hlatshwayo, 2005). All the five coal seams which are in the Witbank coalfield are also
present in the Highveld Coalfield and the No. 4 seam is the most economically viable
(Chabedi, 2013). As Sasol’s Chemical Industries and Sasol Synthetic Fuels requires
about 40 million tons of coal per year, the reserves of highveld coalfield are significant
to the long-term life of these projects (Jeffrey, 2005).
Soutpansberg Coalfield
Soutpansberg coalfield is located north of the Soutpansberg mountains in the Limpopo
Province. The coalfield is situated between longitudes 28°E and 32°E and latitudes
22°S and 23°S. Soutpansberg coalfield is subdivided into Mopane, Tshipise and Pafuri
Sub-coalfields (Barker, 1999). Sparrow (2012) defines seven sub-basins for the
Soutpansberg coalfield, from west to east these being the Waterpoort, Mopane, Sand
River, Mphefu, Tshipise South, Tshipise North and Pafuri sub-basins. The Coalfield’s
shape and location were influenced by the west-southwest and east-northwest
orientated faults which follow the general trend of the Limpopo Mobile Belt. The
coalfield comprises up to seven distinct coal-seam hosted in a 40 m multi-seam coal-
mudstone association in the west (Mopane coalfield). Pafuri coalfield comprises two
individual seams, the upper seam is 3 m thick and the lower seam which is about 100
m deeper and approximately 2 m thick (Hancox and Gotz, 2014). According to
Sparrow (2012), the coal rank, yield and coke strength after reaction (CSR) in the
Soutpansberg coalfield increase towards the east while (Fig. 2.2).

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Figure 2.2: Map illustrating metallurgical coal trends of the Soutpansberg coalfield
(Sparrow, 2012).
2.2 Geology of The Mushithe Coal Occurrence
2.2.1 Limpopo Mobile Belt
According to Hancox and Gotz (2014), Soutpansberg coalfield’s location and shape
were influenced by east-northwest and west-southwest orientated regional faults that
follow the general trend of the Limpopo Mobile Belt. Limpopo mobile belt is an
Archaean-aged high-grade metamorphic complex located between the lower-
metamorphic grade granite-greenstone Zimbabwe and Kaapvaal Cratons (Khoza et
al., 2013). Based on lithology and structure, the belt is subdivided into three zones;
the Northern Marginal Zone (NMZ), the Central Zone (CZ), and the Southern Marginal
Zone (SMZ) (Light, 1982). The belt is about 700 km long, ranging from 240 to 320 km
in width, covering an area of about 185 000 square kilometres. The belt is interpreted
as the site where the Kaapvaal and Zimbabwe Craton collided about 2.7 billion years
ago (Fig. 2.3) (Gore et al., 2009).

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Northern Marginal Zone
The Northern Marginal Zone is a long, narrow zone which is approximately 550 km in
length and occurs entirely in Botswana and Zimbabwe. Rocks of the Northern Marginal
zone comprise of high-grade metamorphic equivalents of the nearby Archean granite-
greenstones of the Zimbabwe Craton (Gore et al., 2009). The Northern Marginal Zone
is separated from the Zimbabwe Craton by a southward-dipping ductile North Limpopo
Thrust Zone (Rigby et al., 2011).
Central Zone
The Central Zone is situated between the Northern Marginal Zone and Southern
Marginal Zone. The Central Zone has been divided into three metamorphic complexes
namely; the Phikwe Complex, Beit Bridge Complex and the Mahalapye Complex
(Light, 1982). The Central Zone is separated from the Northern Marginal Zone and
Southern Marginal Zone by the Palala-Sunnyside and Magagohate-Triangle shear
zones respectively (Rigby et al., 2011). Sand River Gneiss formed about 3283 Ma is
the oldest unit in the Central Zone and it consist of grey migmatitic quartz diorite gneiss
(Gore et al., 2009).
Southern Marginal Zone
The Southern Marginal Zone is found within South Africa and encompasses the high-
grade metamorphic equivalents of the nearby Archaean granite-greenstone rocks of
the Kaapvaal Craton (Gore et al., 2009). Rocks of the Southern Marginal Zone are
divided into two categories, Baviaanskloof Gneiss and Bandelierkop Formation. The
Southern Marginal Zone comprise granulite-facies granitoid-greenstone material of
the Kaapvaal Craton (Light, 1982). The northwards-dipping Hout River Shear Zone
separates the Southern Marginal Zone from the Kaapvaal Craton (Rigby et al., 2011).

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Figure 2.3: Simplified geological map of the Limpopo Mobile Belt (Gore et al., 2009)
2.2.2 Soutpansberg Group
Rocks of the Soutpansberg Group are overlain by the Karoo-aged rocks comprising
the Soutpansberg Coalfield (Hancox and Gotz, 2014). According to Brandl (2002), the
Soutpansberg Group is a volcano-sedimentary sequence formed about 1 800 million
years ago either as an east-west trending rift basin or a post-graben formed between
two crustal blocks, Limpopo Mobile Belt in the north and Kaapvaal Craton in the south.
The Soutpansberg Group has a total preserved thickness of up to 5 km and it is 40 km

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wide and 250 km long (Bumby et al, 2001). Soutpansberg volcano-sedimentary
succession is sub-divided into seven formations (Fig. 2.4): Tshifhefhe, Sibasa,
Fundudzi, Wyllie’s Poort, Nzhelele, Stayt and Mabiligwe Formations (Brandl, 2002).
Lower Successions of the Soutpansberg Group are generally exposed along the
southern slopes of the Soutpansberg mountain range as the strata are monoclinal and
gently dipping to the north (Geng et al., 2014).
Figure 2.4: Illustrative map showing the distribution of geological formations within the
Soutpansberg group (Geng et al., 2014).
Tshifhefhe Formation
Tshifhefhe Formation forms the base of the Soutpansberg Group. Tshifhefhe
Formation is only a few meters thick and can be up to 10 m thick in localised areas
(Geng et al., 2014). Strongly epidotised and chloritised clastic sediments which include
conglomerate, shale, and greywacke made up the composition of the Formation
(Brandl, 2002). The rocks overlying the Tshifhefhe Formation are strongly believed to
have extruded in an almost featureless terrain owing to the unit’s almost uniform
thickness seen across the whole of Soutpansberg (Geng et al., 2014).

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Sibasa Basalt Formation
Sibasa Formation succession overlies the Tshifhefhe Formation and is composed
dominantly of volcanic rocks with minor clastic sediments. The succession is
approximately 3 700 m thick in the eastern part of Soutpansberg and about 100 m
thick in the west (Geng et al., 2014). The massive amygdaloidal basalts present in the
Sibasa Formation are generally epidotised (Brandl, 2002). Shale, Sandstone and
infrequent conglomerate are clastic sediments interbedded within the formation and
often form persistent marker beds which are up to 50 m in thickness (Geng et al.,
2014).
Fundudzi Formation
Fundudzi Formation is a predominantly siliciclastic unit which only developed in the
eastern half of the Soutpansberg Group (Bumby et al., 2001). The unit is
approximately 1 900 m thick, mainly consisting of argillaceous and arenaceous
sediments with few thin pyroclastic layers (Brandl, 2002). The formation is understood
to have formed as a result of fluviatile deposition in a braided, alluvial environment due
to the presence of immature sandstone, shale and siltstone indicative of a mixed load
deposit (Geng et al., 2014).
Wyllie’s Poort Formation
Wyllie’s Poort Formation is a 1 000 m thick unit which forms the base of the
Soutpansberg Group’s upper succession where its lower contact is a prominent
regional unconformity. The entire unit covers the whole of Soutpansberg depositional
basin, and it is made up almost entirely of arenaceous succession with rare volcanic
rocks and local interbeds of argillaceous sediments (Brandl, 2002). The formation is
made up of red-pink quartzite with few pebble washes. The depositional environment
of the quartzites is believed to have formed in a deltaic to shallow marine environment
due to their high textural and mineralogical maturity (Geng et al., 2014; Bumby et al.,
2001).

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Nzhelele Formation
Nzhelele Formation is the uppermost unit of the Soutpansberg Group. It comprises
approximately 400 m thick layer of basalt at the base and uppermost argillaceous and
arenaceous sedimentary rocks (Bumby et al., 2001). The unit has a maximum of 2300
m of preserved thickness. Dark red argillaceous sandstones make up the composition
of the sediments (Geng et al., 2014). Volcanic rocks comprise of basaltic lava and
several thin layers of pyroclastic rocks layers are copper-bearing (Brandl, 2002).
Stayt Formation and Mabiligwe Formation
Stayt and Mabiligwe Formations outcrop north of the main Soutpansberg outcrop. The
Formations have maximum thicknesses of approximately 1 800 m and 50 m
respectively. Stayt Formation comprises basalt at the base, overlined by argillaceous
sediments containing thin layers of interbedded pyroclastic. Mabiligwe Formation is
entirely a clastic succession restricted to a small area along Limpopo River (Barker,
1999). The strongly fractured portions of the Stayt Formation are known for copper
mineralization (Brandl, 2002).
2.2.3 Karoo Supergroup
The Karoo aged rocks, containing the Soutpansberg Coalfield, overly the ±1850 Ma
Soutpansberg Group and rock of the Beit Bridge Complex (Malaza, 2013). The
sedimentary part of the Karoo Supergroup is subdivided into four main
lithostratigraphic units, which from the base up are the Dwyka, Ecca, Beaufort and
Stormberg (Fig. 2.5) (Hancox and Gotz, 2014). Vryheid formation of the Ecca Group
hosts the most economically extractable coal (Mphaphuli, 2017). Like elsewhere in
South Africa the basal part of the Karoo succession is formed by Dwyka Group
equivalents. In the Soutpansberg Coalfield these are referred to as the Tshidzi
Formation and occur as a unit between 5 and 20 m in thickness (Malaza, 2013). It is
composed of diamictite and coarse-grained sandstone. According to Sparrow (2012),
these deposits reflect glacial and fluvioglacial depositional environments. The upper
contact of the Tshidzi Formation is currently defined as being gradational into the
overlying Madzaringwe Formation, which forms the basal part of the Ecca Group in
the coalfield (Malaza, 2013).

14
The Madzaringwe Formation comprises up to 200 m of alternating feldspathic, often
cross-bedded sandstone, siltstone and shale containing coal seams. The basal part
of the formation consists of a 30 m thick unit of carbonaceous siltstone and mudstone,
shaly coal and thin coal seams (Hancox and Gotz, 2014). This unit is overlain by a
succession of alternating layers of coal, grey black siltstone and carbonaceous
mudstone, and very fine to medium-grained sandstone. In the upper third of the
formation, prominent coal seams occur interlayered with carbonaceous mudstones
(Cairncross, 2001). Madzaringwe Formation is overlain by the Mikambeni Formation,
which reaches a thickness of between 20 and 150 m and is composed mainly of
medium to dark grey siltstone, minor carbonaceous mudstone and red to grey
sandstone. Disseminated thin coal seams occur throughout the formation (Malaza,
2013).
Figure 2.5: Stratigraphy and correlation of the Main Karoo Basin and the Soutpansberg
Basin (Malaza, 2013).

15
2.3 Coal Overview
2.3.1 Coal Formation
Coal is an organic rock composed of fossilised remains of plant material which have
undergone gradual chemical and physical change through time. Coal consists of the
chemical constituents which contain carbon, hydrogen, oxygen, nitrogen and sulphur
(Phupheli, 2007). According to the World Coal Association (2018), coal formation
began about 360 million to 290 million years ago during the Carboniferous Period.
Coal begins as peat which forms in a swampy environment that contains the
necessary conditions to allow peat to form and be into beds which then are gradually
converted to coal (Phupheli, 2007). After the decomposition of plants, inorganic
compounds remain in the peat and combine to form discrete minerals (Schweinfurth,
2009).
Humification
Humification is the process whereby remains of plants and animals are transformed
into complex heterogeneous mixtures of humic substances through abiotic and
biochemical pathways (Zaccone et al., 2018). As these remains accumulate in a
saturated, partially decayed vegetations would settle to the bottom of the bog or
swamp and transform into peat if suitable conditions prevent full decay. Oxidative
browning reactions of biomolecules such as polyphenols, sugars, proteins, and amino
acids cause the dark colouration of humic substances (Hardie et al., 2009). After the
peat is buried, it undergoes a series of physical and chemical changes referred to as
“coalification” (Schweinfurth, 2009).
Coalification
Coalification is a continuous process whereby coal of increasing rank is produced
resulting from an increase in both pressure and temperature resulting from burial in
the earth (Schweinfurth, 2009). High temperatures are considered as the most
important controlling factor affecting coalification. High temperature may be caused by
an igneous intrusion or is associated with depth of burial heat associated with earth’s
crust geothermal heat (Schweinfurth, 2009; Mphaphuli, 2017). Both organic and

16
mineral matter in coal are affected by coalification. As coalification proceeds, organic
matter constituents rich in water, hydrogen, and oxygen are gradually expelled from
coal it becomes relatively enriched with fixed carbon (Schweinfurth, 2009). The level
that coal has reached a coalification stage is termed its rank (Mphaphuli, 2016). Major
coal ranks from highest to lowest are anthracite, bituminous coal, sub-bituminous and
lignite (Zaccone et al., 2018).
2.3.2 Macerals
Coal macerals are the organic components of coal which are derived from remains of
plant materials. Different types of macerals are present in coal and they help in the
determination of coal quality (Schweinfurth, 2009). Coal macerals are regarded as the
descriptive equivalents of minerals in coal (Phupheli, 2007). All coal-derived benefits
such as energy output on combustion, metallurgical properties, in-situ methane
absorption and its use as a hydrocarbon source alternative, are derived fundamentally
from coal macerals (Ward, 2002). Macerals are distinguished from each other based
on colour, polishing hardness, shape and reflectance. Based on chemical composition
and optical reflectance, three groups of macerals can be identified, namely: Exinite,
Inertinite and Vitrinite (Table 2.1).
Table 2.1: Macerals and maceral group description of coal (Mphaphuli, 2017).
Maceral Group Maceral Morphology Origin
Vitrinite
(huminite)
Telinite Cellular structure Cells walls of trunks,
branches,
roots, leaves
Collinite Structureless Reprecipitation of
Dissolved
organic matter in a gel
form
Vitrodetrinite Fragments of
vitrinite
Very early degradation of
plant
and humic peat particles
Sporinite Fossil form Mega-microspores
Cutinite Bands which may
have
appendages
Cuticles – the outer layer
of leaves,
shoots and thin stems
Exinite (liptinite) Resinite Cell filling layers or
dispersed
Plant resins, waxes and
other
Secretions

17
Alginite Fossil form Algae
Liptodetrinite Fragments of
Exinite
Degradation residues
Fusinite Empty or mineral
filled cellular
structure; cell
structure usually
well preserved
Oxidized plant material –
mostly
charcoal from burning of
vegetation
Semifusinite Cellular structure Partly oxidized plant
Material
Macrinite Amorphous
‘cement’
Oxidized gel material
Inertinite Inertodetrinite Small patches of
fusinite,
semi-fusinite or
macrinite
Redeposited inertinites
Micrinite Granular, rounded
Grains ∼1 μm
in diameter
Degradation of macerals
during
Coalification
Sclerotinite Fossil form Mainly fungal remains
Vitrinite
Vitrinite is the most common coal maceral, resulted from coalification of structureless
decayed plant materials. Vitrinite is sometimes referred to as “pure coal” due to its
property to become denser, tougher and glassy when subjected to high heat levels as
a result of depth in the earth or heat from igneous intrusion (Schweinfurth, 2009). Level
of heat or maturity to which coal has been subjected is determined by an index of
vitrinite reflectance (Studer, 2008). Vitrinite is difficult to differentiate from other
macerals in high-rank coal (Mphaphuli, 2017). A humic-acid portion of humic
substances from which vitrinite originates contains carbon, hydrogen and nitrogen
(Studer, 2008).
Liptinite
liptinite maceral group is also referred to as exinite. It develops from relatively
hydrogen-rich plant parts such as algae, spores and resin (Studer, 2008). Based on
the original plant parts, liptinite maceral group is further grouped into alganite, sporinite
and resinite (Schweinfurth, 2009). When heated, exinite group yields much more
volatile matter compared to other maceral groups. Its reflectance increases with the
increase of coal rank (Mphaphuli, 2017). Compared to other maceral groups, exinite

18
macerals are more enriched in hydrogen resulting in exinite-rich coal to produce large
amount and high-grade liquid fuel when they are subjected to destructive distillation
(Schweinfurth, 2009).
Inertinite
Plant materials that are highly altered and degraded during peat stage formation of
coal yields the inertinite maceral group. Inertinite maceral group are formed by the
same type of plant material as vitrinite group, but they are more subjected to a varying
degree of partial burning and oxidation (Mphaphuli, 2017). With increasing coal rank,
inertinite macerals show very little change in the chemical and physical properties
(Phupheli, 2007). Inertinite group is subdivided into: fusinite, semifusinite, funginite,
macrinite, secretinite, inertodetrinite and micrinite. Fusinite is the most prominent
maceral group of inertinite and it is believed to have formed from burned fossilised
wood resulting from ancient forest fires (Studer, 2008; Mphaphuli, 2017).
2.3.3 Coal Mineralogy
Mineral matter in coal refers to inorganic material in coal associated with peat
accumulation and other subsequent processes (Mphaphuli, 2017). Geology of the
surrounding environment of the coal deposit affects the coal’s mineralogical
constituents (Akinyemi, 2011). The understanding of coal mineralogy is very important
in understanding the depositional environment of coal. Based on origin, coal mineral
matter is grouped into intrinsic and extrinsic. Intrinsic inorganic matter refers to mineral
which was present in the original plant tissues and extrinsic inorganic matter refers to
the introduced form of mineral matter (Mphaphuli, 2017). Minerals in coal can occur
as single crystal or cluster of crystals which are void space filling or mixed with organic
matter (Schweinfurth, 2009).
When coal is burned, the type and composition of ash produced are dependent on the
mineral matter of coal (Studer, 2008). Illite clay, pyrite, quartz and calcite are the most
common minerals found in coal (Schweinfurth, 2009). According to Akinyemi (2011),
mineral matter in coal can be divided into siliceous or non-siliceous. Siliceous minerals

19
mainly consist of aluminium silicates such as mica and kaolin whereas non-siliceous
minerals consist mainly of pyrite, sulfates, carbonates and chlorides.
Minor inorganic constituents in coal which are in a concentration of parts per million
(ppm) are referred to as trace elements (Phupheli, 2007). About 76 to 90 naturally
occurring elements of the periodic table may be contained in coal, the majority of these
elements occur in trace amounts. Some coal beds may be concentrated with trace
elements such as silver; zinc and germanium which may make the particular coal bed
a more valuable resource (Schweinfurth, 2009). Arsenic, antimony, cadmium,
beryllium, cobalt, chromium, manganese, mercury, lead, selenium and nickel are
some of the trace elements of environmental concern when coal is burned (Wagner
and Hlatshwayo, 2005).

20
CHAPTER 3: MATERIALS AND METHODS
This chapter presents the procedures and methods used in the collection of important
information and steps used in analyses and processing (Fig. 3.1).
Figure 3.1: Flow chart illustrating methods and procedures applied in the study.

21
3.1 Preliminary Work
Preliminary work is the procedure of preparing to undertake the actual fieldwork. The
purpose of the procedure is to outline methods and materials which are vital to the
study before the actual fieldwork is carried out. The preliminary work provides
knowledge about the study area and possible constraints that may have an impact in
achieving the set of objectives. Using this information, a field plan was drawn up
outlining how the fieldwork will be carried out, the number of personnel required,
duration of work, methods to be applied and the appropriate resources required.
3.3.1 Desktop Study
The desktop study comprises obtaining information about the study area using
published and unpublished literature that may be useful in conducting the study. The
literature used includes but not restricted to Books, journals, theses, online resources,
photographs, online resources, maps and unpublished sources. The data and
information attained are associated with the planned project and helps in providing
knowledge about the work that will be carried out in the study area. The desktop study
also prepares the researcher psychologically and contributes to the selection of
required equipment to undertake the study.
3.1.2 Reconnaissance Survey
A reconnaissance survey was undertaken by travelling to the field with the objective
of familiarising the researchers with the immediate surroundings of the study area. A
reconnaissance survey was used to aid the researcher in identifying areas of
significant interest to the study and awareness of the surroundings. Geological setting,
topography, drainage, soil type, vegetation type and sedimentary facies were
investigated during this stage.
3.2 Fieldwork
Fieldwork comprises the collection of relevant information within the study area
analysis.

22
3.2.1 Coal Sampling
Coal and shale samples were sampled in situ from a surface coalbed exposure at
Mushithe`. The coal and shale samples were sampled using channel sampling
method. According to Thomas (2012), channel samples are representative of the coal
from which they are sampled. To prevent the effect of coal oxidation from the exposed
coal seams, the outcropping part of the seams were first cleared to expose the fresh
part. Three channel profiles spaced 6 m apart and covering the whole coalbed
exposure delineated perpendicular coal bedding to cut across all lithology within the
coalbed (Fig. 3.2). After the face was cleared, a shallow box-cut was made for the total
thickness of the exposed coal seam. Once this was accomplished, the seam was
divided into subsections, thickness and macroscopic properties of different lithology
were recorded into a field book. A channel of uniform cross-section was cut manually
into the coal seam and all the coal within the cut section was collected in a plastic
sampling bag with proper labelling. All the samples were kept in closed plastic bags in
order to minimize contamination and oxidation. A total of 21 coal and shale samples
were collected. About 2 kg of each sample within the Coalbed was sampled for further
laboratory analysis.
Figure 3.2: Coalbed image showing three profiles (A-C) delineated for channel
sampling method.

23
3.3 Laboratory Work
Laboratory work was conducted on coal and shale sampled from the study area to
deduce information on coal quality including its chemical and physical characteristics.
To accomplish the objectives of the study, samples were subjected to the following
tests in the laboratory: ultimate analysis, proximate analysis, X-Ray Fluorescence
spectrometry, petrographic studies and calorific value determination.
Sample Preparation
Sample Preparation for Chemical Analytical Techniques
Samples were first crushed with a jaw crusher to reduce the size of samples to smaller
particles sizes. Crushed samples were placed in Kraft sample bags and then oven
dried for 12 hours at a temperature of 110oC using the Vacutec 970 drying oven. After
drying, samples were allowed to cool for 2 hours at room temperature. Afterwards, the
samples were milled using the Retsch RS 200 milling machine for 8 minutes at 750
rev/min until the sample was pulverized to approximately 75 μm. Carbon-steel mill pots
were first cleaned with pure quartz in order to minimize cross-contamination of
samples. A small sample to be milled was then milled to coat the milling pots before
the actual sample.
21 Coalbed samples were palletized for X-ray fluorescence spectrometry analysis.
Samples were palletized by adding sample into a pallet cup and using boric acid
powder (H3BO3) as a binding agent and acetone (C3H6O) to prevent cross-
contamination of samples. Pulverized sample powder weighing about 15 grams was
pressed with about 3 grams of boric acid as a binding agent. The pellet cup was
carefully placed in the piston of a manual laboratory hydraulic press and a force of 30
tons was applied for 30 seconds. Once the pellet was ready, it was removed from the
die-set and placed in a container with a label indicating sample ID (Fig. 3.3). From the
9 identified coal samples, their pulverized samples were split into four separate 100 g
samples with riffle splitter to produce representative samples for different tests.

24
X-ray Fluorescence Spectrometry
X-ray fluorescence spectrometry (XRF) is an analytical method to determine chemical
composition of all kinds of materials. The material can be liquid, solid, powder, filtered
or other form. Chemical composition of material is determined by a process whereby
electrons are displaced from their atomic orbital positions, releasing a burst of energy
that is characteristic of a specific element. This release of energy is then registered by
the detector in then XRF instrument, which in turn categorizes the energies by element
(Brouwer, 2010). X-ray fluorescence spectrometry was used to deduce chemical
composition of 21 samples (9 coal and 12 shale samples). The XRF spectrometer was
first calibrated with a copper disc to ensure accuracy of the instrument (Fig. 3.3).
Figure 3.3: Sample preparation: (A) sample crushing with a jaw crusher, (B) Vacutec
970 drying oven for removing moisture in samples, (C) Retsch RS 200 milling machine
for pulverizing samples, (D) palletizing milled samples, (E) pressing pellets with a
hydraulic press and (F) XRF Spectrometer for analysing chemical composition of
samples.

25
Sample Preparation for Petrographic Characterisation of Coal
Coal petrographic study was conducted at the University of Johannesburg. Coal
samples were dispatched as crushed particles of < 1000 μm. Three coal samples were
chosen for petrographic characterisation based on their calorific value and proximate
analysis results. The samples were block mounted following the South African Bureau
of Standards (SABS) ISO 7404-2 and prepared to a final 0.05micron polish using a
Struers Tegraforce polisher at the University of Johannesburg.
Coal Petrographic Analysis
Representative splits of each of the three crushed coal were mixed with epoxy resin
and prepared as polished sections for petrographic analysis. Coal petrographic
analysis were performed by Prof. Wagner at the University of Johannesburg. The
polished blocks were analysed using a Zeiss Axio Imager M2m reflected light
petrographic microscope fitted with a Hilgers Fossil system for vitrinite reflectance and
carbon particle determination at a magnification of x500 under reflected light, with oil
immersion. The samples were analysed for maceral group identification and Vitrinite
reflectance. Maceral group analysis also included mineral matter identification
following the SABS ISO standard 7404-part 4. The main maceral groups were
identified as well as recording petrographically observable mineral phases.
Coal Analysis Techniques
Ultimate Analysis
ultimate analysis involves the determination of the weight percentage of major
constituents of coal such as carbon, hydrogen, nitrogen, sulphur, and usually by
difference, oxygen. Ultimate analysis is used together with the calorific value of coal
to perform combustion calculations such as sulphur emissions, feed rates and boiler
performance (Niksa, 2018). Nine coal samples were analysed for ultimate analysis.
Ultimate analysis conducted at the University of the Witwatersrand, Department of
Analytical chemistry, using the LECO CHNS analyser.

26
Carbon and Hydrogen
A weighed amount of coal was placed in a glazed porcelain crucible and inserted into
the combustion tube under the first furnace, in which the sample was burned in
oxygen. The combustion products were permitted to move over the heated copper
oxide and lead chromate and into the absorption train. The copper oxide makes certain
of complete combustion of the carbon and hydrogen in the coal, however, the lead
chromate absorbs the oxides of sulfur. The pre-weighed absorbers in the absorption
train absorb water and carbon dioxide, carbon and hydrogen in the sample was
determined from the increase in weight of absorbers. The combustion was
accomplished by placing the ground coal to pass through a 250-μm sieve in a stream
of dry oxygen at temperatures of the order of 850°C to 900°C.
Nitrogen
Pulverized coal was boiled with a concentrated sulphuric acid containing potassium
sulphate and a suitable catalyst to reduce the time for digestion. The catalyst was
usually a mercury salt, selenium compound, or a mixture of the two. The nitrogen
content in coal was determined by digesting coal sample (1 gm) in Kjeldahl flask with
potassium sulphate, selenium oxide and sulphuric acid and subsequently by distillation
and titration (Niksa, 2018).
Sulphur
To determine sulphur content in coal, 1 g of the analysis sample was thoroughly mixed
with 3 g of Eschka mixture, which is a combination of two parts by weight of light
calcined magnesium oxide with one part of anhydrous sodium carbonate. The
combination of sample and Eschka mixture was placed in a porcelain crucible (30 mL)
and covered with another gram of Eschka mixture. The crucible was placed in a muffle
furnace, heated to a temperature of 800±25°C, and held at this temperature until
oxidation of the sample was complete. The sulphur compounds evolved during
combustion react with the magnesium oxide (MgO) and sodium carbonate (Na2CO3)
and under oxidizing conditions are retained as magnesium sulphate (MgSO4) and

27
sodium sulphate (Na2SO4). The sulphate in the residue was extracted and determined
gravimetrically.
Oxygen
Oxygen was determined by deduction from 100, the summation of the percentages of
moisture, ash, carbon, hydrogen, nitrogen, and sulphur. The following equation was
used (Speight, 2005):
Oxygen = 100 − (Moisture + Ash + Carbon + Hydrogen + Nitrogen + Sulphur)
Proximate Analysis
Proximate analysis involves the determination of four main constituents of coal,
namely; moisture, ash, volatile matter and fixed carbons (by difference) (Kataka et al.,
2018). Nine coal samples were analysed by proximate analysis. Proximate analysis
tests were conducted at ALS-Witlab Laboratory (Pty) Ltd, Witbank.
Moisture
The total moisture in coal is the determination of the moisture that resides within the
coal matrix excluding water of crystallisation of the mineral matter. A large copper
cylinder oven containing 7 identical copper cylinders was used for moisture testing.
The sample was passed through a 250 µm mesh sieve. One gram of sample was then
taken, and oven dried for an hour at a temperature of 107±3 °C. The conditions were
monitored regularly to avoid contamination of samples; the moisture-laden air at that
temperature was removed and substituted by fresh air. The following equation was
used to determine the moisture content of coal samples (Speight, 2005).
moisture content = (
Mi − Mf
Mi
)
Where: Mi = mass of sample before heating
Mf = mass of sample after heating

28
Ash
Ash is the residue left over after the combustion of coal under specified conditions and
comprises predominantly oxides and sulphates. A coal sample was placed in a
porcelain dish for 4 hours in an adequately ventilated furnace at a temperature of
700±50 °C. This was such that there was total removal of the organic matter from the
sample through incineration. Burnt coal was weighed to get its total mass. To acquire
accurate values, the total mass of the porcelain dish was also recorded before and
after burning. The ash content was determined using the following formula (Speight,
2005):
ash content(%) =
Mi − Mf
Mi
× 100
Where: Mi=mass of coal before incineration
Mf = mass of coal after incineration
Volatile matter
Volatile matter refers to materials that are driven off when coal is heated to 950°C in
the absence of air under specified conditions. To determine the volatile matter, 1 g of
coal was weighed and placed in a pre-weighed platinum crucible with a close-fitting
cover. The crucible was then suspended at a stated height in the furnace chamber.
The temperature of the region in the furnace where the crucible was suspended was
retained at 950 ± 20°C. After the more rapid discharge of volatile matter, as showed
by the loss of the luminous flame, the cover of the crucible was tapped to make sure
that the lid was still appropriately held to prevent the entrance of air. After heating 7
minutes, the crucible was removed from the furnace and cooled. After cooling, the
crucible was immediately weighed. The difference between percentage loss of weight
and percentage moisture is equals the volatile matter.
Fixed carbon
Fixed carbon is useful in the determination of the proficiency of coal-burning
equipment. Fixed carbon is the solid combustible residue that remains after a coal

29
particle is heated and the volatile matter is expelled. Moisture content, volatile matter
and ash content values were used to calculate fixed carbon. The following equation
adapted from Speight (2005) was used to determine fixed carbon (FC):
FC = 100 − (Moisture content + Volatile matter + Ash content)%
Calorific Value
Calorific value provides information relating to the heat energy of coal. In this study,
procedures for calorific value were carried out in pure oxygen at 2500 kPa. This was
performed by using a bomb calorimeter connected to a Supercal software. The system
was used after the stabilisation temperature of about 36.3°. Before analysis the actual
samples, a benzoic standard of calorific value 26.428 MJ/kg was used for verification
and calibration. Following this, pulverised coal was weighed to 0.4 g in a crucible, with
a cotton thread dipped in the coal and placed in a bomb for analysis. The bomb was
filled with oxygen and then placed in a calorimeter where the analysis started
automatically after closing the lid; a value was obtained and compared to values
indicate in Table 3.1.
Table 3.1: classification of coal based on caloric value and proximate analysis
parameters as used in South Africa (Steyn and Minnitt, 2010).
Domestic Coal Specifications
Parameter Units A grade B grade C grade D grade
Calorific Value MJ/kg >27,5 >26,5 >25,5 >24,5
Total Sulphur Maximum% (AR) 12,0 12,0 8,0 8,0
Ash Maximum% (AR) 15 16 18 21
Volatile Matter Maximum% (AR) 24,0 23,0 23,0 23,0
Sulphur Maximum% (AR) 1,0 1,0 1,0 1,5

30
CHAPTER 4: RESULTS AND DISCUSSION
The results of the analysis conducted on all samples are presented and discussed in
this chapter in the following order: coalbed stratigraphy, petrographic analysis, coal
analysis (proximate, ultimate analysis and calorific value), and whole rock
geochemistry data analysis. The results attempt to aim to give an insight into the coal
quality and rank as well as the mineralogy of coal.
4.1 Coalbed Stratigraphy
A composite profile of the Mushithe coal occurrence is presented in Figure 4.1. The
coal and shale beds were distinguished from the field using their physical properties.
Shale samples were fine-grained and exhibited fissility (strong tendency to break in
one direction, parallel to the bedding) as opposed to coal which does not have fissility.
Colour and lustre were also used to distinguish between coal and shale. Shale was
grey in colour and having a dull appearance while coal samples are black in colour,
light weight and massive without visible sedimentary structures such as laminations.
Using physical properties, three coal seams identified. The coal seams were occurring
in the coalbed with alternating layers of extremely jointed shale beds. The basal seam
consists of bright coal with thickness range of 0.3-0.4 m, with an average of 0.33 m.
The middle seam consists of a 0.2 m to 0.4 m thick bright coal with an average
thickness of 0.3 m. The upper seam is a relatively thin layer of coal with thickness
range of 0.07 m to 0.2 m with an average of 0.157 m. The upper seam was becoming
thinner towards profile A. The zone of thinning may point towards the attenuation of
the seams, or that seam is splitting, bringing about a thinner upper leaf which can be
attributed to organic accumulation disturbance and replacement by clastic deposition
for a brief period (Thomas, 2012). A normal fault was noted between profile A and B
causing coal towards profile A to move downwards relative to profile B and C (Fig 4.1).
The middle seam exhibits ‘‘melange’’ or mixing of lithotypes towards profile B and C.
Mixing of lithotypes is likely caused by faulting (Thomas, 2012).

31
Figure 4.1: Coalbed stratigraphy of the Mushithe coal occurrence.

32
4.2 Petrographic Data Analysis
Maceral group analysis indicates that the Mushithe coal are vitrinite-rich, with
significant proportions (9.1 – 45 vol%) of visible mineral matter (Table 4.1). Vitrinite
content ranges from 70.2 – 82 vol% with an average of 77.77 vol%. Inertinite content
ranges from 18.0 – 29.8 vol%, averaging 22.23% on mineral matter free basis (mmf).
Liptinite maceral content was not reported in coal from Mushithe (Fig. 4.2). Coal 1B
reported the highest vitrinite content (82.0 vol% mmf) (Fig. 4.3). High content of
Vitrinite reported from Mushithe coals is consistent with the findings of Kruszewska
(2003), who stated that coal from the Soutpansberg coalfield are generally rich in
vitrinite content in contrast to coal from Mpumalanga coalfields which are dominated
by inertinite. Absence of liptinite content from Mushithe coals is again supporting
Kruszewska (2003), that liptinite content of South African coals rarely exceeds 7% by
volume of the total maceral composition. There were cracks associated with vitrinite,
some filled with mineral matter (Fig. 4.4 and 4.5). This is because vitrinite macerals
are relatively brittle in comparison to other maceral groups (Mphaphuli, 2017).
Table 4.1: Maceral group data analysis.
Sample identification Coal 1B Coal 2A Coal 3C
inc. mm Mmf inc. mm Mmf inc. mm Mmf
Maceral
group
(vol%)
Vitrinite 74.5 82.0 67.0 70.2 66.7 81.1
Inertinite 16.4 18.0 28.5 29.8 15.5 18.9
Liptinite 0.0 0.0 0.0 0.0 0.0 0.0
Mineral matter 9.1 45 17.7
Total reactive
macerals
74.5 82.0 67.0 70.2 66.7 81.1

33
Figure 4.2: Major maceral groups in coal.
0
10
20
30
40
50
60
70
80
90
Vitrinite Inertinite Liptinite Total reactive macerals
Concentration
(vol%)
Macerals
Coal 1C Coal 2A Coal 3C

34
Figure 4.3: Micrographs showing identified Vitrinite, Inertinite macerals and alteration
immersion lens for Sample Coal 1B.

35
Figure 4.4: Micrographs showing identified Vitrinite, and Inertinite macerals, taken at
a magnification of x500, under white reflected light using an oil immersion lens for
Sample Coal 2A.

36
Figure 4.5: Micrographs showing identified vitrinite, Inertinite macerals and alteration
immersion lens for Sample Coal 3C.

37
Reflectance of Vitrinite results are presented in Table 4.2. Coal 1B reported a mean
RoV% of between 0.836 - 1.064, averaging 0.94. The mean vitrinite reflectance values
of Coal 2A range from 0.912 - 1.172 with an average of 1.00. Coal 3C reported a mean
RoV% of between 0.738 - 1.118, averaging 0.95. According to UNECE (1998) coal
classification, Coal 1B, 2A and 3C are ranked as bituminous medium rank C,
bituminous medium rank B and bituminous medium rank C respectively. Coal 2A is
more mature in terms of rank when compared to Coal 1B and Coal 3C. Coal rank
decreases from east to west across the coalfields of Limpopo Province (Sparrow,
2012). This is noted when comparing vitrinite reflectance of coals from Tshikondeni
coal mine with coal from Mushithe and Waterberg coalfield. A decreasing coal rank is
noted from Tshikondeni coal nine (1.23), Mushithe coal occurrence (0.96) to
Waterberg coalfield (0.63).
Table 4.2: Vitrinite reflectance data analysis
Petrographically identifiable minerals are presented in Table 4.3. Clay, quartz, pyrite,
carbonate and other minerals were identified petrographically. Clay minerals are the
most dominant with an average of 8.23 vol% followed by pyrite (1.57 vol%), quartz
(0.33 vol%) and carbonate minerals (0.067 vol%) (Fig. 4.6). Coal 3C reported the
highest clay mineral matter (14.0 vol%). Other minerals have average vol% of 0.23.
Coal 3C reported the highest mineral matter content (17.6 vol%) followed by Coal 1B
(9.1 vol%) and Coal 2A (4.6 vol%). High content of mineral matter in coal from
Sample identification: Coal 1 B Coal 2A Coal 3C
Vitrinite
reflectance
Random vitrinite
reflectance
0.94 1.00 0.95
standard
deviation
0.047 0.049 0.081
# points 99 99 100
Range 0.836 -1.064 0.912 - 1.172 0.738 -1.118
Rank category Med Rank C
bituminous
Med Rank B
bituminous
Med Rank C
bituminous

38
Mushithe supports findings of Mphaphuli (2017), who reported that coal from the
Soutpansberg coalfield are generally rich in mineral matter/ash.
Table 4.3: Mineral matter data analysis.
Sample ID Coal 1B Coal 2A Coal 3C
Mineral Matter (vol%)
Clay 6.9 3.8 14.0
Quartz 0.2 0.3 0.5
Pyrite 2.0 0.5 2.2
Carbonate 0.0 0.0 0.2
Other 0.0 0.0 0.7
Total Mineral matter 9.1 4.6 17.6
Figure 4.6: Mineral matter content associated with coal.
0
2
4
6
8
10
12
14
16
clay quartz pyrite carbonate other
Concentration
(Vol%)
Coal 1C Coal 2A Coal 3C Average

39
4.3 Coal Data Analysis And Classification
Proximate Analysis
The percentages of moisture, volatile matter ash content and fixed carbon of all the
seams have been determined (Table 4.4). Proximate analysis data shows that coal
from Mushithe has an average ash content of 19.87 wt% in the upper seam; 41.7 wt
% in the middle seam and 22.13 wt% in the basal seam. Coal 2C has the highest ash
content (66,4 wt%) compared to other coal. According to Mphaphuli (2017), coal with
more than 50 wt% ash is considered a carbonaceous rock. Ash content range of 9.1 -
66.4 wt% with an average of 27.9 wt% are reported in coal from Mushithe which
indicates that coal from Mushithe are classified as high-ash content coal-type as per
classification of Wood et al. (1983), where coal is generally termed as low-ash (≤ 8%
ash content), medium-ash (≥8% to ≤ 15% ash content) and high-ash coal (≥15% ash
content). High ash content present in coal from Mushithe can be attributed to high
mineral matter content identified during petrographic analysis.
Basal seam coals have the highest moisture content with an average of 12.23 wt%
and the middle seam has the lowest moisture content (8.37 wt%). Generally, the
moisture values varied from 5.60 wt % to 13.60 wt% (Fig 4.7). Due to high inherent
moisture content, it can be concluded that basal seam coals will take more time for
heating during coal utilization. The upper seam has the highest volatile matter content,
with an average of 28.93 wt%, whereas the middle seams has the lowest volatile
matter content (23.83 wt%). As a result of high volatile matter, the upper seam coal
will ignite more easily when compared to the middle and the basal seam coal as coal
with high volatile-matter content ignite easily and are highly reactive in combustion
applications (Speight, 2005). The fixed carbon content which has a direct relationship
with the calorific value varied between 40.40 wt% (upper seam), 27.77 wt% (middle
seam) and 38.60 wt% (basal seam). It could be observed from Table 4.4 that the
middle seam has the lowest average fixed carbon content and therefore it is expected
that calorific values for middle seam coal will be lower compared to the basal and
upper seam.

40
Table 4.4: Proximate analysis of Mushithe coal samples.
Sample ID Inherent
moisture
Ash content Volatile matter Fixed carbon
Coal 1A 11.10 29.30 27.60 32.0
Coal 1B 12.0 18.30 27.30 42.40
Coal 1C 13.60 18.80 26.40 41.40
Coal 2A 11.60 9.10 26.60 57.70
Coal 2B 7.90 49.60 25.50 17.00
Coal 2C 5.60 66.40 19.40 8.60
Coal 3A 13.10 13.90 28.50 44.50
Coal 3B 12.8 27.40 31.20 28.60
Coal 3C 6.50 18.30 27.10 48.10
Average 10.47 27.90 26.62 35.59
Figure 4.7: Comparison between inherent moisture, ash content, volatile matter and
fixed carbon in coal.
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
Coal 1A Coal 1B Coal 1C Coal 2A Coal 2B Coal 2C Coal 3A Coal 3B Coal 3C Average
Concentration
(wt%)
Sample ID
Inherent moisture (%) Ash content (%) Volatile matter (%) Fixed carbon (%)

41
Ultimate Analysis
Elemental analysis of coal is presented in Table 4.5. Ultimate analysis data indicates
that the coal contain high proportions of carbon (ranging from 14,21% to 57,13%), with
relatively low concentrations of sulphur (0,1 - 0,32%), nitrogen (0,41 - 1,47%) and
hydrogen (ranging from 1,94% to 3,41%) (Fig 4.8). The oxygen content of the coal
was found to range from 16,94% to 32,67%. Mushithe coal has sulphur content range
of 0,11% - 0,32% with an average of 0.24% indicating that the coal is low sulphur coal
type as per classification of coal proposed by Chou (2012), where coal is generally
termed as low sulphur (≤ 1% sulphur content), medium sulphur (≥1 to ≤ 3% sulphur
content) and high sulphur coal (≥3 wt% sulphur content). Sulphur content in low
sulphur coal type is derived mostly from sulphur content of the original plant material
incorporated at the time of peat accumulation (Chou, 2012). Petrographic analysis
indicates the presence of pyrite in coal samples. Coal 3C has the highest sulphur
content (0.32%), which is substantiated by its relatively higher pyrite content 2.2 vol%
determined through petrographic analysis.
Table 4.5: Elemental composition analysis of Mushithe coal.
Sample ID Carbon
(%)
Hydrogen
(%)
Nitrogen
(%)
Sulphur
(%)
Oxygen (%)
Coal 1A 37.97 3.05 1.0 0.22 28.47
Coal 1B 48.58 3.41 1.37 0.3 28.04
Coal 1C 47.77 3.37 1.37 0.3 28.39
Coal 2A 57.13 3.28 1.47 0.32 28.62
Coal 2B 23.04 2.39 0.62 0.12 24.24
Coal 2C 14.21 1.94 0.41 0.11 16.94
Coal 3A 50.57 3.21 1.39 0.31 30.62
Coal 3B 35.4 3.13 1.17 0.24 32.67
Coal 3C 54.44 3.21 1.39 0.32 22.34

42
Figure 4.8: Comparison of carbon, hydrogen, sulphur and oxygen content in coal
Calorific Value
Results obtained from the calorific value determination for nine coal samples are
shown in Table 4.6. Calorific values of coal within the Mushithe coal occurrence ranges
from 4.66 MJ/kg to 20,99 MJ/kg. Sample Coal 2A has the highest calorific value
compared to other samples. This can be attributed to its higher fixed carbon content
(57.70 wt. %). The average calorific value for basal, middle and upper seams is 15.65
MJ/kg, 10.96 MJ/kg and 16.18 MJ/kg respectively. Low average calorific value for the
middle seam can be attributed to its relatively high average ash content (41.7 wt%).
Mushithe coals have relatively lower average calorific values compared to coal from
Vele (17,53 MJ/kg), Makhado (18,17 MJ/kg) and Tshikondeni collieries (28,24 MJ/kg)
(Mphaphuli, 2017) (Fig. 4.9). According to Steyn and Minnitt (2010) domestic coal
specification, based on calorific value, coals from Mushithe are classified below D
grade coal (˃24.5 MJ/kg).
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
Coal 1A Coal 1B Coal 1C Coal 2A Coal 2B Coal 2C Coal 3A Coal 3B Coal 3C Average
Concentration
(wt%)
Sample ID
Carbon Hydrogen Nitrogen Sulphur oxygen

43
Table 4.6: The heating values of Mushithe coal samples.
Sample ID Calorific Value (MJ/Kg)
Coal 1A 12.88
Coal 1B 17.40
Coal 1C 16.68
Coal 2A 20.99
Coal 2B 7.22
Coal 2C 4.66
Coal 3A 17.63
Coal 3B 11.20
Coal 3C 19.72
Average 14.26
Figure 4.9: Comparison of heating values of coal between Mushithe coal occurrence,
Vele, Makhado and Tshikondeni collieries.
12,88
17,40
16,68
20,99
7,22
4,66
17,63
11,20
19,72
14,26
28,24
18,17
17,53
0,00
5,00
10,00
15,00
20,00
25,00
30,00
Heat
energy
(MJ/kg)
Sample ID

44
4.4 Whole Rock Geochemistry Data Analysis
Major Oxides
The proportions of inorganic elements (reported as oxides) in the coal and shale,
derived from XRF analysis, are given in Table 4.7 and Table 4.8. Average UCC (Upper
Continental Crust) (Taylor and McLennan, 1985) were also included for comparison
purposes. Chemical composition as determined by XRF analysis of coal revealed
major presence of SiO2, Al2O3, Fe2O3, CaO, MgO, Na2O and minor presence of TiO2,
K2O, P2O5 and MnO (Fig. 4.10). Concentrations of SiO2, Al2O3, Fe2O3, CaO, MgO
and Na2O ranging from 13.96% to 46.65%, 4.51% to 22.37%, 1.66% to 8.72% 0.32%
to 10.39%, 0.13% to 4.67% and 0.41% to 3.74% respectively. Bulk chemical
composition of shale revealed major presence of SiO2, Al2O3, TiO2, Fe2O3 with minor
K2O, MgO, CaO, P2O5, Na2O and presence of MnO (Fig. 4.11). Concentrations of
SiO2, Al2O3, TiO2 and Fe2O3 range from 40.96% to 61.58%, 27.82% to 39.23%,
0.99% to 2.051% and 0.66% to 5.1% respectively. Prevalence of Al2O3 and SiO2 in
both coal and shale samples indicates the dominance of quartz and clay minerals.
Prevalence of clay and quartz minerals in coal samples also supports the high
contents of clay (8.23 vol%) and quartz (0.3 vol%) determined by petrographic
analysis.
In comparison with UCC (Taylor and McLennan, 1985), coal samples are low in SiO2,
Al2O3, MnO, MgO, CaO, Na2O, K2O and high in TiO2, TiO2 and P2O5. Shale samples
are low in SiO2, Fe2O3, MnO, MgO, CaO, Na2O, K2O, P2O5 and high in Al2O3 and
TiO2 in comparison to UCC. Enrichment of aluminium in shale is possibly resulting
from its ability to be easily absorbed by clays and concentrates in the finer, more
weathered materials. There is an intermediate to strong positive correlation between
TiO2, Fe2O3, MnO, K2O, P2O5 with SiO2 and Al2O3 which indicates that all these
elements have a common detrital source. Negative intermediate correlation between
these elements with Na2O is most likely due to leaching of the coal by water or to the
organic components of the coal (Table 4.9). Weak correlation between CaO with other
elements indicates that CaO is likely of epigenetic source. The degree of relationship
is expressed by correlation coefficient which range from correlation ( -1 ≤ r ≥ +1), where
If r = Zero means no correlation between the two variables, 0 < r < 0.25 = weak

45
correlation, 0.25 ≤ r < 0.75 = intermediate correlation, 0.75 ≤ r < 1 = strong correlation.,
If r = 1 represent perfect correlation.

46
Table 4.7: X-ray Fluorescence Spectrometry analysis data for major oxides associated with coal (wt %).
Sample ID Coal 1A Coal 1B Coal 1C Coal 2A Coal 2B Coal 2C Coal 3A Coal 3B Coal 3C
SiO2 24.77 36.4 18.8 25.2 16.49 46.65 16.36 18.81 13.96
TiO2 0.895 0.887 0.508 0.907 0.477 1.111 1.363 0.705 0.751
Al2O3 9.89 17.12 7.69 12.65 5.9 22.37 6.64 7.18 4.51
Fe2O3 4.2 5.33 1.93 1.66 4.8 7.93 3.62 3.03 8.72
MnO 0.011 0.12 0.006 0 0.011 0.067 0.002 0.019 0.015
MgO 3.0161 3.5162 2.6154 0 2.6567 1.2803 0.1356 4.668 0.3211
CaO 4.96 6.22 3.48 0.32 4.43 1.38 0.89 10.39 1.13
Na2O 0.882 0.593 2.156 0.803 1.533 0.411 1.755 3.738 1.632
K2O 0.33 0.36 0.25 0.23 0.32 0.58 0.19 0.13 0.39
P2O5 0.188 0.28 0.109 0.179 0.123 0.257 0.317 0.393 0.099

47
Table 4.8: X-ray Fluorescence Spectrometry analysis data for major oxides associated with shale (wt %).
Sample
ID
Shale
1A
Shale
1B
Shale
1C
Shale
2A
Shale
2B
Shale
2C
Shale
3A
Shale
3B
Shale
3C
Shale
4A
Shale
4B
Shale
4C
SiO2 61.58 44.48 40.96 41.4 61.17 59.11 50.06 51.56 59.03 49.874 52.33 46.1
TiO2 0.993 1.154 1.14 1.161 1.006 1.128 1.942 1.896 1.055 1.595 2.051 1.344
Al2O3 27.82 33.92 30.98 31.5 31.83 33.98 34.65 39.23 31.18 36.604 39.06 33.05
Fe2O3 0.66 0.81 1.19 1.2 1.03 1.11 1.24 0.78 5.1 0.7029 0.69 1.04
MnO 0.001 0.002 0.001 0.002 0.003 0.002 0.001 0.004 0.01 0.0179 0.005 0.002
MgO 0.8704 0.4486 0.1724 0.1704 0.5107 0.4086 0.3998 0.4884 0.4529 0.4603 0.4474 0.2847
CaO 0.57 0.25 0.21 0.21 0.3 0.1 0.24 0.19 0.18 0.1729 0.16 0.21
Na2O 0.0 0.0 0.0 0.0 0.0 0.0 0.153 0.0 0.0 0.0129 0.0 0.0
K2O 0.82 0.48 0.25 0.26 1.09 1.24 0.49 0.45 0.97 0.4829 0.47 0.53
P2O5 0.063 0.125 0.08 0.081 0.186 0.146 0.123 0.053 0.142 0.0659 0.053 0.088

48
Table 4.9: Table showing Correlation coefficient matrix for major elements in coal.
Figure 4.10: Comparison of major oxides associated with coal.
SiO2 TiO2 Al2O3 Fe2O3 MnO MgO CaO Na2O K2O P2O5
SiO2 1
TiO2 0.367155 1
Al2O3 0.992487 0.393304 1
Fe2O3 0.317284 0.158029 0.251405 1
MnO 0.750286 0.1606 0.724297 0.418589 1
MgO 0.069292 -0.4933 0.002958 -0.20289 0.323719 1
CaO -0.05736 -0.41314 -0.1143 -0.22067 0.243811 0.955485 1
Na2O -0.62832 -0.36183 -0.64384 -0.34651 -0.42579 0.431459 0.585832 1
K2O 0.695197 0.142558 0.649199 0.79525 0.519406 -0.20499 -0.36648 -0.70121 1
P2O5 0.271054 0.520631 0.268952 -0.14437 0.314108 0.344184 0.494667 0.327173 -0.28975 1
0
10
20
30
40
50
60
70
Coal 1A Coal 1B Coal 1C Coal 2A Coal 2B Coal 2C Coal 3A Coal 3B Coal 3C average UCC
Concentration
(wt%)
Sapmle ID

49
Figure 4.11: Comparison of major oxides associated with shale.
Trace Elements Analysis
For this study, potentially hazardous air pollutants (HAPs) in coal and shale were
considered (Table 4.10). HAPs have the potential to cause negative health and
environmental impacts during coal utilization and in-situ (Ishtiaq et al., 2018). For
comparative purposes, concentrations of potentially hazardous air pollutants will be
compared with average global concentrations of coal. Potentially hazardous air
pollutants in coal are grouped into elements of major concern, moderate concern,
minor concern and radioactive elements (Swaine, 1990). Highest concentrations of
HAPs in coal were observed for Ni and the lowest for Cd (Fig. 4.12) while Highest
concentrations of HAPs in shale were observed in Pb and the lowest for Cd (Fig. 4.13).
Coal samples showed variation in PHEs concentrations, and the general trends of
average HAPs concentrations were Ni > Pb > Cr > As > Th > Co > U >Sb > Cd.
General trends of average HAPs in shale were Pb > Ni > Cr >Th > As > U > Co > Sb
> Cd.
0
10
20
30
40
50
60
70
Shale
1A
Shale
1B
Shale
1C
Shale
2A
Shale
2B
Shale
2C
Shale
3A
Shale
3B
Shale
3C
Shale
4A
Shale
4B
Shale
4C
average UCC
Concentration
(wt%)
Sample ID

50
Major Concern Elements
Concentration of As in coal range from 7.7 ppm to 21.4 ppm with an average of 13.41.
similarly, concentration of As in shale range from 8 ppm to 23.8 ppm (average 13.21
ppm). Arsenic levels in these samples are higher compared to global coal average
values of 5.0 ppm (Zhang et al., 2004). Average concentration of Cadmium is 0.1 ppm
for both coal and shale samples. Cd was determined in low concentrations in the
Mushithe coals when compared to global values (0.6 ppm). Due to the low Cd
occurrence in these samples, Cadmium is unlikely to be of health or environmental
concern. Concentration of lead in coal samples range from 71.6 ppm to 199.6 ppm
with an average of 125.11 ppm and 76.7 ppm to 221.7 ppm (average 127.84 ppm) for
shale samples. Pb concentration is higher compared to average global values (25
ppm). Owing to the high concentration of Pb occurrence in shale and lead samples,
lead is likely to be of health or environmental concern.
Moderate Concern Elements
Chromium concentrations range from 45.3 ppm to 212 ppm with an average of 106.02
ppm in coal samples and 39.4 ppm to 81.6 ppm (average 58.26 ppm) in shale samples.
Ruppert et al. (1996) concludes that the occurrence of high chromium values (up to
176 ppm) may be due to the deposition of detrital Cr-bearing minerals transported into
the palaeoswamp. Chromium concentration in Mushithe coal occurrence is much
higher comped to global average values (10 ppm) (Swaine, 1990). Nickel
concentrations in coal ranges from 196.6 ppm to 559 ppm, averaging 323.12 ppm and
47 ppm to 147.7 ppm (average 109.95 ppm) in shale samples. The average
concentration of nickel in Mushithe coal occurrence is higher compared to global
average (14 ppm). Attributable to their high concentration compared to the global
average, nickel and chromium are likely to cause health or environmental problems.
Minor Concern Elements
Concentration of cobalt in coal ranges from 4.0 ppm to 25.3 ppm, averaging 12.03
ppm and 1.5 ppm to12 ppm (average 3.13 ppm) in shale samples. The average
concentration of cobalt in world coals lower (6.1 ppm) compared to cobalt

51
concentrations in Mushithe coal occurrence. Due to the high cobalt occurrence in
these samples, cobalt is likely to be of health or environmental concern. Antimony was
determined in low concentrations in Mushithe coals when compared to global values
(3 ppm) (Ketris and Yudovich, 2009). Sb concentration in coal range from 0 ppm to
0.6 ppm with an average of 0.17 ppm and 0 ppm to 0.4 ppm for shale samples. Due
to low concentrations, Sb concentrations in this study is unlikely to cause
environmental or human health problems.
Radioactive Elements
Uranium concentration in coal ranges from 2.6 ppm to 33.3 ppm (10.16 ppm) and 2.6
ppm to 12.7 ppm (average 4.85 ppm) for shale samples. The average concentration
of U in Mushithe coal occurrence is higher compared to global average (1.9 ppm)
(Swaine, 1990). According to Seredin and Finkelman (2008), coal with U concentration
of greater than 5 ppm represent a significant public health risk. Thorium concentration
range from 7.7 ppm to 18.7 ppm with an average of 12.20 ppm and 13.4 ppm to 28.6
ppm (average 21.03 ppm) in shale. Thorium concentrations in Mushithe coals is higher
compared to global average (3.1 ppm) (Ketris and Yudovich, 2009).

52
Table 4.10: X-ray Fluorescence Spectrometry analysis data for trace elements associated with coal (ppm).
Sample ID Coal 1A Coal 1B Coal 1C Coal 2A Coal 2B Coal 2C Coal 3A Coal 3B Coal 3C
Ag 1.7 0.6 1.1 2.3 1.2 0.2 1.1 0.9 0.7
As 13.5 16.6 7.7 9.4 8 21.4 15.9 12.3 15.9
Ba 726 719.7 437.5 734.8 414.3 556.4 1075.5 584.5 618.9
Bi <3 <3 <3 <3 <3 <3 <3 <3 <3
Cd 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1
Ce 139.1 404 323 171 124.7 162.7 646.6 350.8 165
Co 9.9 12.4 5.4 4 11.7 18.8 8.6 7 25.3
Cr 102.6 91.1 68.1 45.3 120.8 108 98.9 62.1 212
Cs 5.4 5.4 5.4 5.4 5.4 5.4 5.4 5.4 5.4
Cu 93.4 74.8 63 101.9 77.2 86.5 231.4 129.1 176.7
Dy 13.3 17 6.1 5.3 15.3 25.2 11.5 9.6 27.7
Er 2.2 2.8 1.1 0.9 2.5 4.1 1.9 1.6 21
Eu 0.1 1.2 0.1 0 0.1 0.7 0 0.2 0.2
Ga 93.9 64.8 135.5 42.6 130.5 46.9 137.3 147.4 95.4
Gd 6.9 15.9 0.6 0 7.9 21.7 3 5.4 20.4
Ge 7.6 3.6 6.3 1.7 4.6 3.1 4.6 4.2 2.6
Hf 0 10 0 16.1 5.5 8.8 25.3 14.2 27.7
La 55.8 69.8 23.1 29.1 54.1 98.7 61.2 38.8 95.3
Mo <2 <2 <2 <2 <2 <2 <2 <2 <2

53
Nb 18.9 20 9.6 14.3 7.8 16.1 22.6 14.2 15
Ni 202.3 310.8 558.5 216.5 559 305 198.4 251.6 196.6
Pb 128 154.4 71.6 87.7 74.1 199.6 147.9 114.9 147.8
Rb 31.9 34.5 66.8 35.8 23.2 34.3 52.5 53.1 25.3
Sb 0.2 0.4 0 0 0 0.4 0 0 0.6
Sc <3 <3 <3 <3 <3 <3 <3 <3 <3
Sm <10 <10 <10 <10 <10 <10 <10 <10 <10
Sn 3.8 2.7 3.4 3.7 3.5 3 3.2 3.3 3.8
Sr 678.2 822.6 466.6 550.4 264.6 455.5 870.2 1424.7 191.6
Ta <2 <2 <2 <2 <2 <2 2.8 <2 2.2
Tb 1.3 1.6 0.6 0.5 1.5 2.4 1.1 0.9 3.5
Th 9.3 14.3 7.7 12 <3 15.1 10.4 10.1 18.7
Tl <3 <3 5.8 <3 5.8 <3 5.7 6.8 4.2
U 11.9 6 6 8.9 2.9 7.6 12.3 33.3 2.6
V 213.2 200.8 162.6 206.9 206.5 257.8 315 175.8 282.3
W 10.9 19 31.3 <3 37.2 <3 7.4 <3 0
Y 95.4 100.9 99.7 38.2 69 71.6 42.7 48.5 43.6
Yb 76.3 115.7 197.5 77.8 201.5 117.2 74.1 91.9 80.5
Zn 248.3 746.5 557.5 59.4 588.8 725 57.5 199.6 84.4
Zr 314.1 347.6 193.4 296.2 133.5 386.7 387.3 394.2 282.2

54
Table 4.11: X-ray Florescence Spectrometry analysis data for trace elements associated with shale (ppm).
Sample
ID
Shale
1A
Shale
1B
Shale
1C
Shale
2A
Shale
2B
Shale
2C
Shale
3A
Shale
3B
Shale
3C
Shale
4A
Shale
4B
Shale 4C
V 192 250.9 237.7 230.2 203.1 236.3 372.1 368.5 209.8 338 388 291.5
Cr 44.1 72.6 81.6 71.8 50.6 70.1 42.3 49.4 62.7 39.4 46.4 68.1
Co 1.5 1.9 2.9 2.8 2.7 2.5 2.8 2 12 1.7 1.7 3.1
Ni 94.6 147.7 143.1 141.9 62.8 47 89.6 132.3 92.1 113.2 120.2 134.9
Cu 57.8 117.1 100.6 95.7 82.9 168.3 273.2 182.8 116.4 163.3 170.3 120.9
Zn 25.6 50.9 16.2 20.3 125.2 29.8 24.4 35.7 315 26.7 33.7 43.2
Ga 31.2 56.1 49.1 48.9 39.9 53 70.3 69.8 31.7 64.5 71.5 51.6
Ge 1.4 1.7 1.2 1.8 1.2 1.6 1.6 1.6 1.5 1.2 1.2 1.7
As 13.8 12.6 10.7 10.3 11.1 13 23.8 14.8 17.2 8 15 8.2
Rb 52.6 40.6 38.7 35.3 66.3 90.1 59.4 59.2 48.2 55 62 45.7
Sr 203.3 325.3 78.1 70.7 263.7 299 255.8 186.7 194.9 163.8 170.8 158.2
Y 39.8 43.4 48.3 43.3 51.8 55.6 39.1 42.6 38.8 34.2 41.2 40.9
Zr 694.7 460.5 491.9 413.4 603.4 454.7 619.4 670 445.3 636.4 643.4 483
Nb 22.5 22.9 26.6 22.6 25.3 26.7 43.1 44 18.2 36.6 43.6 27.5
Mo 1.3 0.9 6.3 4.9 7.5 0.9 1.3 8.3 1 0.9 7.9 5.9
Ag 0.6 0.8 0.8 0.4 0.4 0.7 0.6 0.6 0.5 0.9 0.9 0
Cd 0.1 0.1 0.1 0.2 0 0.1 0.1 0.1 0.1 0.1 0.1 0.1
Sn 3.4 4.1 4.1 3 3.7 2.6 3.6 3.3 2.6 4 4 2.9
Sb 0 0.3 0.1 0.2 0 0.3 0.3 0.4 0.2 0 0 0

55
Cs 5.4 5.4 5.4 5.4 5.4 5.4 5.4 10.3 5.4 5.4 5.4 5.4
Ba 799.3 918.9 908.5 924.4 808.6 899.8 1507.3 1472.8 845.1 1581.1 1588.1 1060.6
La 22.3 30.2 28.9 30.5 27 31.7 46.1 40.9 75.7 36.8 43.8 28.1
W 0 0 0 0 0 0.9 1.5 0 0 0 0 0
Ta 1 1.6 1.4 1.4 1.2 2.1 3.3 2.3 1.6 2.2 2.2 1.6
Hf 22.5 21.4 21.9 20.9 22.8 33 41.4 40.7 22.2 27.1 34.1 32.2
Tl 1.1 3.2 2.8 1.3 2.4 3 2.8 3.9 2.3 2.9 2.9 2.9
Pb 128.2 117.6 100.1 95.8 103.5 121.2 221.7 137.6 160.1 132.3 139.3 76.7
Bi 0.5 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4
Ce 94.5 134.1 95.4 466.5 408.9 479.3 767.8 760.1 117.1 794.7 801.7 156.2
Eu 0 0 0 0 0 0 0 0 0.1 0 1 0
Gd 1.8 0 1.3 2.6 0.9 0.4 0.9 0 12.2 0 0 0
Tb 0.2 0.3 0.4 0.4 0.4 0.4 0.4 0.3 1.5 0.2 0.2 0.4
Dy 2.1 2.6 3.8 3.8 3.3 3.5 3.9 2.5 16.2 2.2 2.2 3.3
Er 0.3 0.4 0.7 0.7 0.6 0.6 0.6 0.5 2.7 0.4 0.4 2.5
Yb 33.9 52.6 51.5 51.1 23.3 17.9 33 47.2 39.1 35.9 42.9 48.5
Th 14.4 21.3 28.6 25.3 16.8 24.5 22.5 23.8 13.4 14.5 21.5 25.7
U 3.5 3.9 3.4 2.6 3.8 6.4 12.7 3.2 4.8 5.3 5.3 3.3
S 171.2 375.4 544.8 547.3 48.4 48.6 167.8 51.4 53.5 42.6 49.6 374.8

56
Figure 4.12: Comparison of potentially hazardous air pollutants associated with coal.
Figure 4.13: Comparison of potentially hazardous air pollutants associated with shale.
0
100
200
300
400
500
600
Coal 1A Coal 1B Coal 1C Coal 2A Coal 2B Coal 2C Coal 3A Coal 3B Coal 3C Mean Global
average
Concentration
(ppm)
Sample ID
As Cd Cr Co Ni Pb Sb Th U
0
50
100
150
200
250
Shale 1A Shale 1B Shale 1C Shale 2A Shale 2B Shale 2C Shale 3A Shale 3B Shale 3C Shale 4A Shale 4B Shale 4C Mean
Concentration
(ppm)
Sample ID
As Cd Cr Co Ni Pb Sb Th U

57
CHAPTER 5: CONCLUSIONS AND RECOMMENDATIONS
5.2 Conclusions
From this study the following conclusions can made:
• Coal occurrence in Mushithe area is contained within a faulted zone, where coal
is intercalated with shale. Three coal seams were identified with average
thickness of 0.33 m, 0.3 m, and 0.156 m respectively.
• Petrographically, vitrinite is the most dominant maceral group (77.77 vol%),
followed by inertinite (22.23 vol%). No liptinite content was reported. Samples
from Mushithe reported a mean RoV% ranging from 0.738 -1.172; hence the
coal samples are ranked between bituminous medium rank B and bituminous
medium rank C based on to the UNECE (1998) coal classification.
• In terms of coal quality, Mushithe coal is characterised by high-ash content
(27.90 wt%), apparently as a result of the multiple intercalation of coal and
shale. Sulphur content in coal range between 0,11 – 0,32 wt% (average 0.24
wt%) indicating a low-sulphur coal-type (Chou, 2012).
• Petrographic analysis indicated that Mushithe coal is dominated by clay (8.23
vol%), pyrite (1.57 vol%), quartz (0.33 vol%) and carbonate minerals (0.2 vol%).
SiO2 and Al2O3 are the most dominant major oxides in coal. High
concentrations of SiO2 and Al2O3 indicates the prevalence of quartz and clay
minerals. Strong positive statistical relationship between SiO2 and Al2O3 with
other elements indicates that all these elements have a common source, likely
to be detrital. Arsenic, Chromium, Cobalt, Nickel, Lead, Thorium and Uranium
are potentially hazardous trace elements of concern which have a higher
concentration than the global average, whilst Cadmium and Antimony are lower
than the global average.
• Calorific values of coal in Mushithe ranges from 4.66 MJ/Kg to 20,99 MJ/Kg,
averaging 14.26 MJ/kg. The average calorific value of coal is relatively lower
compared to Tshikondeni (28,24 MJ/kg), Makhado (18.17 MJ/kg) and Vele
collieries (17.53 MJ/kg). Lower calorific value of the Mushithe coal can be
attributed to high ash content in coal. According to Steyn and Minnitt (2010)
coal classification, coal from Mushithe can be classified below grade D.

58
5.3 Recommendations
The study recommends the following:
• Due to lack of drillhole data in the area, boreholes should be sunk in the area
to determine the stratigraphy as well as extent of the coal seams in the area.
• Other exploration techniques such as geophysical survey and remote sensing
should be applied to determine the geology of the area, as the current study
focused mainly on coal quality hence the scope of the work is limited.
• Detailed exploration of coal in the area should be conducted so as to ascertain
coal reserves in the area.

59
REFERENCES
Akinyemi, S.A. (2011). Geochemical and Mineralogical Evaluation of Toxic
Contaminants Mobility in Weathered Coal Fly Ash: As a Case Study, Tutuka Dump
Site, South Africa, University of Western Cape, Bellville, Unpublished dissertation,
346pp.
Barker, O.B. (1999). A techno-economic and historical review of the South African
Coal Industry in the 19th and 20th centuries. In: Pinheiro, H.J. (Ed.), A Techno-
economic and Historical Review of the South African Coal Industry in the 19th and
20th Centuries and Analyses of Coal Product Samples of South African Collieries
1998–1999. Part 1. Bulletin 113 South African Bureau of Standards, pp. 1–63.
Bumby, A., Eriksson, P., van der Merwe, R. and Steyn, G. (2001). A half-graben setting
for the Proterozoic Soutpansberg Group (South Africa): evidence from the Blouberg
area. Sedimentary Geology, 147(1-2), pp.37-56.
Brandl, G. (2002). The geology of the Alldays area. Explanation sheet 2228, Alldays.
Geological Survey South Africa, 71 pp.
Brouwer, p., (2010). Theory of XRF third edition. PANalytical B.V., Amelo, The
Netherlands, 62 pp.
Cairncross, B. (2001). An overview of the Permian (Karoo) coal deposits of southern
Africa. Journal of African Earth Sciences, 33(3-4), pp.529-562.
Chabedi, C. K. (2013). Analysis of Technical Factors for Underground Mining of Deep
Waterberg Coal Resources. University of Witwatersrand, Johannesburg, Unpublished,
163pp.
Chou, C.L. (2012). Sulphur in coals: a review of geochemistry and origins. Int. J. Coal.
Geol. 12, pp. 1 - 13.
Environmental Systems Research Institute (ESRI). (2018). ArcGIS Release 10.1.
Redlands, CA.

60
Geng, H., Brandl, G., Sun, M., Wong, J. and Kröner, A. (2014). Zircon ages defining
deposition of the Palaeoproterozoic Soutpansberg Group and further evidence for
Eoarchaean crust in South Africa. Precambrian Research, 249, pp.247-262.
Gore, J., James, D., Zengeni, T. and Gwavava, O. (2009). Crustal structure of the
Zimbabwe craton and the Limpopo belt of southern Africa: new constraints from
seismic data and implications for its evolution. South African Journal of Geology,
112(3-4), pp.213-228.
Hancox, P. (2016). The Coalfields of South-Central Africa: A Current Perspective.
Episodes, 39(2), p.407.
Hancox, P.J., and Gotz, E. (2014). South Africa’s Coalfields: A 2014 Perspective.
International Journal of Coal Geology, volume 132, pp. 170 – 254.
Hardie, A., Dynes, J., Kozak, L. and Huang, P. (2009). The role of glucose in abiotic
humification pathways as catalyzed by birnessite. Journal of Molecular Catalysis A:
Chemical, 308(1-2), pp.114-126.
IEA (2014). South Africa Role Coal Energy Security. International Energy Agency.
http://www.iea.org/ciab/South_Africa_Role_Coal_Energy_Security.pdf. [Accessed 6
Apr. 2018].
Ishtiaq, M., Jehan, N., Khan, S., Muhammad, S., Saddique, U., Iftikhar, B. and
Zahidullah, J. (2018). Potential harmful elements in coal dust and human health risk
assessment near the mining areas in Cherat, Pakistan. Environmental Science and
Pollution Research, 25(15), pp.14666-14673.
Jeffrey, L.S. (2005). Characterization of the coal resources of South Africa. J. South
Afr. Inst. Min. Metall. 95–102.
Kataka, M., Matiane, A. and Odhiambo, B. (2018). Chemical and mineralogical
characterization of highly and less reactive coal from Northern Natal and Venda-Pafuri
coalfields in South Africa. Journal of African Earth Sciences, 137, pp.278-285.

61
Ketris, M.P., Yudovich, Y.E. (2009). Estimations of Clarkes for Carbonaceous
biolithes: world averages for trace element contents in black shales and coals. Int. J.
Coal Geol. 78 (2), 135–148.
Khoza, D., Jones, A., Muller, M., Evans, R., Webb, S. and Miensopust, M. (2013).
Tectonic model of the Limpopo belt: Constraints from magnetotelluric data.
Precambrian Research, 226, pp.143-156.
Kruszewska, K. (2003). Fluorescing macerals in South African coals. International
Journal of Coal Geology, 54(1-2), pp.79-94.
Light, M.P.R. (1982). The Limpopo mobile belt: a result of continental collision.
Tectonics, 1(4), pp. 325-342.
Malaza, N. (2013). Basin Analysis of the Soutpansberg and Tuli Coalfields, Limpopo
Province of South Africa. Unpublished PhD Thesis, University of Fort Hare, 270 pp.
Mphaphuli, M. (2017). Petrographic consideration of the impact of the Tshipise Fault
on coal quality in the Soutpansberg Coalfield, South Africa, Unpublished Master’s
Dissertation, University of Johannesburg, pp. 9-95.
Netshitungulu, D. (2001). Drought and its impacts on the water resources in the
Northern Region of Northern Province of South Africa. BESc. Hons. thesis submitted
University of Venda 51pp.
Niksa, S. (2018). Predicting ultimate soot yields from any coal. Proceedings of the
Combustion Institute, 37(3), pp.2757-2764.
Phupheli, M.R. (2007). Purifying coal for the production of nuclear graphite.
Unpublished Master’s Dissertation, University of Pretoria, pp. 6-18.
Pinetown, K., Ward, C. and van der Westhuizen, W. (2007). Quantitative evaluation of
minerals in coal deposits in the Witbank and Highveld Coalfields, and the potential
impact on acid mine drainage. International Journal of Coal Geology, 70(1-3), pp.166-
183.

62
Rigby, M., Basson, I., Kramers, J., Gräser, P. and Mavimbela, P. (2011). The
structural, metamorphic and temporal evolution of the country rocks surrounding
Venetia Mine, Limpopo Belt, South Africa: Evidence for a single palaeoproterozoic
tectono-metamorphic event with implications for a tectonic model. Precambrian
Research, 186(1-4), pp.51-69.
Ruppert, L., Finkelman, R., Boti, E., Milosavljevic, M., Tewalt, S., Simon, N., Dulong,
F. (1996). Origin and significance of high nickel and chromium concentrations in
Pliocene lignite of the Kosovo basin, Serbia. International Journal of Coal Geology
29(4), 235– 258.
Seredin, V., Finkelman, R.B. (2008). Metalliferous coals: a review of the main genetic
and geochemical types. Int. J. Coal Geol. 76, 253–289.
Schweinfurth, S.P. (2009). An introduction to coal quality, in Pierce, B.S., and Dennen,
K.O., eds., The national coal resource assessment overview: U.S. Geological Survey
Professional paper 1625-F, Chapter C,16 p.
Sparrow, J. (2012). The Soutpansberg Coalfield “The Forgotten Basin”. Presentation
at the inaugural FFF Limpopo Conference, October 2012.
Speight, J. (2005). Handbook of Coal Analysis. 1st ed. Hoboken, N.J.: Wiley-
Interscience. 227pp.
Steyn, M. and Minnitt, R.C.A. (2010). Thermal coal products in South Africa. Journal
of the Southern African Institute of Mining and Metallurgy, 110(10), pp.593-599.
Studer, A. (2008). Trace Elements in Miocene Subbituminous Coals from the Swiss
Molasse Basin with Special Attention to Uranium and its Mode of Occurrence.
Unpublished Master’s Thesis, Swiss Federal Institute of Technology (ETH) Zurich, pp.
12-15.
Swaine, D.J. (1990). Organic association of elements in coals. Organic Geochemistry.,
vol. 18, no. 3, pp. 259-261.

63
Taylor, S.R. and McLennan, S.M. (1985). The Continental Crust: Its Composition and
Evolution. Blackwell Scientific Publications, 312 pp.
Thomas, L. (2012). Coal Geology, 2nd Edition. 2nd ed. Chennai: John Wiley & Sons,
pp.137-151.
UNECE (1988). International Coalification System for Medium- and High-Rank Coals.
ECE/COAL115. United Nations Economic Commission for Europe, Geneva, 26 pp.
Van Der Walt, B. (2012). The Petrology, Petrography and Geochemistry of Anomalous
Borehole Core Sequences: A Case Study of Diatreme Activity, University of
Johannesburg, Johannesburg, Unpublished dissertation, 319pp.
Van Heerden, G. (2004). Geotechnical factors affecting high- and low-wall stability in
opencast coal mines. Coaltech 2020 task 1.4, Sub- task 3Acsir Miningtek,
Johannesburg,14pp.
Wagner, N. and Hlatshwayo, B. (2005). The occurrence of potentially hazardous trace
elements in five Highveld coals, South Africa. International Journal of Coal Geology,
63(3-4), pp.228-246.
Ward, C.R. (2002). Analysis and significance of mineral matter in coal seams.
International journal of coal geology, 50, 135-168.
Wood, G.H., Kehn, T.M., Carter, M.D. and Culbertson, W.C., 1983. Coal resource
classification system of the US Geological Survey. US Department of the Interior,
Geological Survey. pp.106-118
World Coal Association (2018). What is coal. [online] World Coal Association.
Available at: https://www.worldcoal.org/coal/what-coal [Accessed 5 Sep. 2018].
Zaccone, C., Plaza, C., Ciavatta, C., Miano, T. and Shotyk, W. (2018). Advances in
the determination of humification degree in peat since Achard (1786): Applications in
geochemical and paleoenvironmental studies. Earth-Science Reviews, 185, pp.163-
178.

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