Galena also called as lead glance which is PbS (lead sulphide) is also the chief are lead. Mainly found in large deposits in and around Australia, US, etc. The typical specimen of galena is about 86% lead and 13.4 % Sulphur by weight. However, some specimens of galena contain upto a few percent silver by weight. Weigh about 0.400 g of galena sample . Add conc.HNO3 and dissolve the ore & then evaporate to dryness on sand bath . Extract the contents in 30 cm3 of 4 N HCI. Filter through Whatman paper No. 41 & dilute the contents to 250 cm3 of distilled water.  Pipette solution out in a 25 cm3 of the diluted solution in a conical flask.  Add 3- 4 drops of xylenol orange . Opening of Ore : Appropriate amount of the sample (0.3 to 0.5 g ) is mixed with 10-15 cm3 of conc. HCl and evaporated to dryness. Then it is extracted with 4 N HCl and boil to get clear solution & filter through Whatman Paper No. 41 & it is collected in 250 cm3 volumetric flask .

1. Chemical Analysis
Of Ores For
Principal
Constituents
Title : Chemical Analysis Of Ores For
Principal Constituents.
Name : Sanat Manohar Sawant
Class : Msc Part 2
Roll no. : 22217018
Paper 3 : Selected Topics In Analytical
Chemistry
1

2. Content
Sr.No Topics
1. Principal Constituent Of Galena.
2. Principal Constituent Of Pyrolusite.
3. Principal Constituent Of Hematite.
4. Principal Constituent Of Monazite
2

3. Galena
• Galena also called as lead glance which is PbS (lead
sulphide) is also the chief are lead. Mainly found in
large deposits in and around Australia, US, etc.
• The typical specimen of galena is about 86% lead and
13.4 % Sulphur by weight.
• However, some specimens of galena contain upto a few
percent silver by weight.
• Galena is one of the easiest ores to smelt. It can be
simply be placed recovered from under the ashes when
the fire goes out.
• Galena is a very important are becomes it serves as an
ore for most of the world's lead production.
Galena
3

4. Analysis Of Galena
1) Weigh about 0.400 g of galena sample .
2) Add conc.HNO3 and dissolve the ore & then evaporate to dryness on sand bath .
3) Extract the contents in 30 cm3 of 4 N HCI.
4) Filter through Whatman paper No. 41 & dilute the contents to 250 cm3 of distilled water.
5) Pipette solution out in a 25 cm3 of the diluted solution in a conical flask.
6) Add 3- 4 drops of xylenol orange .
7) Add dil. HNO3 till colour changes to yellow .
8) Add hexamine powder to the above solution until the solution becomes reddish.
9) Titrate this solution with 0.01 M EDTA.
10) End point is from red to yellowish orange.
 Calculations :
1000 cm3 of 1 M EDTA = 207.29 of Pb
Red To Yellowish Orange
4

5. Pyrolusite
• Pyrolusite is the most common manganese mineral ore .
• It is one of several manganese oxide mineral, which are
all dark grey to black in color.
• It is also a component of the production of steel.
• It is also used in the preparation of chlorine & as an agent
in coloring & dyes.
• Pyrolusite is also used to prepare disinfecting & for
decolorizing glass.
• As a coloring material, it is used in calico printing &
dyeing for imparting violet, amber & black colors to glass
pottery & bricks & also in the manufacture of green &
violet paints.
Calico Printing
Pyrolusite
5

6. a) Opening of Ore :
1) Appropriate amount of the
sample (0.3 to 0.5 g ) is mixed
with 10-15 cm3 of conc. HCl and
evaporated to dryness.
2) Then it is extracted with 4 N HCl
and boil to get clear solution &
filter through Whatman Paper
No. 41 & it is collected in 250 cm3
volumetric flask .
Analysis Of Pyrolusite
6

7. b) Estimation of Iron :
1) The estimation of iron is done
colorimetrically.
2) A calibration curve in the range of 0.5 to 2.5
ppm is prepared .
3) To this a solution of 1,10 - phenonthroline is
added for the formation of coloured complex.
4) 5 cm3 of ore solution is also used for color
development .
5) The absorbance is taken at 520 nm.
6) From the plot of Absorbance vs Conc.in ppm
the conc. unknown can be calculated.
Colorimeter 7

8. c) Estimation of Manganese:
1) The estimation of manganese is carried out
by complexometric titration.
2) 10 cm3 of the stock solution is used for
titration.
3) To this 5 cm3 of 10% Hydroxylamine
hydrochloride and one test tube of
triethanolamine is added along with one test
tube of buffer (pH = 10) .
4) Add 2 drops of thymolphthalexone and
titrate against 0.05 M EDTA , Endpoint will
be from Blue to Pink .
Blue To Pink 8

9. Hematite
• Hematite is heavy and relatively hard oxide
mineral Fe2O3 i.e Ferric oxide that constitutes
the most important iron ore because of its high
iron content (70%) & its abundance.
• The hematite ore occurs in a soft , fine grained
earthy form called red ochre.
• The most important deposits of hematite are
sedimentary in origin.
• The largest production comes from sedimentary
deposit in the lake superior district in North
america.
Hematite
9

10. Analysis Of Hematite
a) Opening of ore :
1) Appropriate amount of sample (0.4 to
0.5 g) is mixed with 10 to 15 cm3 of
conc. HCI & evaporated to dryness.
2) Repeat the procedure by adding 5 cm3
of conc. HCI at a time to dissolve the
sample .
3) Filter through Whatman & collect in
250 cm3 volumetric flask.
10

11. b) Estimation of Iron:
1) Estimation of iron is carried out by redox
titration .
2) To 25 cm3 aliquot of stock solution add 5
cm3 conc. HCI and 3% SnCl2 till solution
becomes colorless.
3) Cool & add 5 % HgCl2 , till turbidity is
formed. Add 1/2 test tube mixture of acid
(H2SO4 + H3PO4) & 3-4 drops of 1% freshly
prepared diphenyl amine indicator .
4) Titrate with 0.05 N K2Cr2O7, end point is
permanent violet colour.
Violet Colour 11

12. Monazite
• Monazite is a rare phosphate mineral with a
chemical composition of (Ce, La, Nd
,Th)(PO4 , SiO4).
• Monazite is a yellowish brown to reddish
brown mineral with a resinous lustre.
• Monazite is principle natural ore of thorium
this contains about 25 % of ThO2 .
• Thorium is a highly radioactive metal &
could be used as a replacement for uranium
in nuclear power generation.
Monazite
12

13. Analysis Of Monazite
1) Appropriate amount of monazite ore in beaker.
2) Add 15 cm3 of acid mixture and heat on sand bath
& evaporate to dryness.
3) Cool & extract contents in 25 ml NaOH and filter .
4) Dissolve the ppt in HCI & filter then extract
solution by using tributyl phosphate.
5) Thorium is obtained as ppt of thorium phosphate
which is then washed with sodium carbonate to
get ppt of ThO2.
6) The residue is cooled & weighed as thorium oxide.
Monazite
13

14.  Chemical analysis of metals ; Sampling and
analysis of metal bearing ores: American
Society for Testing and Materials 1980 -
Technology & Engineering
 Manual of Procedures for Chemical and
Instrumental Analysis of Ores, Minerals, and
Ore Dressing Products.Government of India
Ministry of Steel & Mines, Indian Bureau of
Mines, 1979.
References
14

15.  Icles Motilal
Jhunjhunwala College
 Miss. Aqsa Siddiqui
 Chemistry Department
Acknowledgement
15

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