This presentation discusses heavy minerals, which have a density over 2.8g/cm3 and comprise less than 1% of sandstone. Heavy minerals can be extracted via dry mining of shallow deposits or wet mining using dredges for deeper deposits below the water table. Seventeen placer deposits of heavy minerals have been found along the coast of Bangladesh, containing over 4 million tons of minerals like ilmenite, magnetite, zircon, and rutile. These heavy mineral deposits represent an important economic resource for Bangladesh.

2. A presentation
On
Heavy Minerals


3. submitted by………………
shuvo das
Id No : 14207101
Institute of marine science and fisheries ;
University of chittagong

4. Mineral
A mineral is a naturally occurring solid chemical
substance formed through bio- geochemical
processes, heaving characteristics chemical
composition, highly ordered atomic structure and
specific physical properties.
A mineral is an element or a chemical compound
that is normally crystalline and that has been
formed as a result of geological processes.

6. Heavy Minerals
Heavy minerals have density of > 2.8gcm-3
and
typically comprise less than 1% of a sandstone. They
are more provenance specific than the light mineral
fraction .
Mineral sands contain suites of minerals with high
specific gravity known as heavy minerals.

8.  Furthermore, a distinction is made in the references
according to the density of the useable
heavy minerals:
• the heavy heavy minerals with a density of 6.8-21 g/cm3
(mainly gold, platinum, cassiterite),
• the light heavy minerals with a density of 4.2-6.7 g/cm3
(mainly ilmenite, rutile, zircon,
monazite, magnetite, chromite),
• gemstones with a density of 2.9-4.1 g/cm3 (mainly
diamond).

10. Different types of minerals
Minerals are natural compounds formed through
geological process.
Minerals are needed by the body in small amounts to
help its function properly and strong.
There are two types of minerals :
 Macro Mineral
Trace Mineral

13. Macro Mineral
Macro means “large” in Greek are dietary minerals
needed by the human body in high quantities. The
macro mineral group is made of calcium, phosphorus,
magnesium, sodium, potassium, chloride, sulfur.

16. Micro/Trace Mineral
Trace elements are micronutrients that are chemical
elements. A trace of something means that there is
only a little of it. So even though our body needs
mineral each day in small amounts for good health.
Trace minerals include iron, manganese, copper,
iodine, zinc, fluoride and selenium.

19. Heavy Mineral Extraction
Mining is the process of extracting valuable minerals
or other geological minerals form the earth crust.
Mining in broad sense means extracting of non-
renewable resources water petroleum and natural gas.
Mineral sands mining involves both dry mining and
wet (dredge) mining operation.

20. Heavy Mineral Extraction
The proper extraction processes for heavy minerals depend on
the depth of the groundwater
level, the degree of consolidation of the sediment and its
particle size. If the groundwater level is
sufficiently high and the sediment finely grained, extraction is
mostly economic if large-scale cutter
wheels or cutter head suction dredges that mechanically break
up solidified horizons are used. In
the case of very high extraction banks, the ore sand can be
pushed towards the suction dredger ship
using bulldozers. When gravel and stones are involved (e.g. gold
extraction in Alaska, cassiterite
extraction in South East Asia) floating bucket wheel dredges
are used. If the groundwater level is
very low, scraper bulldozers are used.

22. Dry Mining Process
Dry mining typically involving the extraction of heavy
mineral ore from relatively shallow, unconsolidated,
and free flowing deposits. Dry mining is suitable
where deposits are shallow, contain hard brands of
rock or in a series of unconnected ore bodies.

25. Wet Mining Process
Dredge or wet mining is the best suited to ore
reservoir below the water table. Dredge mine is
artificial ponds, pumping ore in slurry form to a
floating concentrator. The ore is washed through
spirals that use specific gravity to separate the heavy
minerals sands from the lighter quartz and clay.

28. Transportation Deposition Of
Heavy Minerals
The heavy mineral became concentration into a
thin layer, composed of nearly 100% heavy
mineral, is known as heavy infra layer.
Lying beneath a thin surgical layer of low density
sediment is known as light supra layer.
Heavy mineral transported on the upper surface
of the heavy infra layer only when the local and
temporary erosion of light supra layer caused by
large clasts, clast jems or downstream moving
dune like bed forms exposed the heavy infra layer.

30. History of HEAVY MINERALS In Bangladesh
Investigation of radioactive minerals like
MONAZITE by the erstwhile Geological Survey of
Pakistan around the cox’s bazaar sea beach area
started in 1961 and a number of precious heavy
minerals were identified the same year.
After systematic surveys during 1967 to 1969 it was
recognized that a potential zone of heavy mineral
exists along the entire coastal belt, mainly from
cox’s bazaar to badarmokam, and some areas of
maheskhali, kutubdia, and matabari island.

31. Later in 1975 a pilot plan was installed at katali,
cox’s bazaar with the cooperation of the Australian
Government.
By 1985 the nearly 550 km-long coastline of was
surveyed either partially or completely to map the
beach sand heavy minerals.
It was found that the reserves were concentrated
mainly along the sea beaches of chittagong & cox’s
bazaar districts .

33. Present situation of HEAVY MINERALS
in Bangladesh
Untill now 17th
placer deposits are found ; 15th
are in
the cox’s bazaar, ctg. Sea beaches and nearby
offshore islands.
In fact seven are from cox’s bazaar – teknaf sea
beaches.
seven form Maheskhali Island, one each from
Matarbari, Kutubdia, Nijhum Island and Kuakata.
All the seventeen deposits include 20.5 million tons
of raw sand, which contains 4.4 millions of heavy
minerals.

34. Only eight types of economically important heavy
minerals, Namely
●Ilmenite , Magnetite, Zircon, Rutile, Garnet,● ● ● ● ●
Leucoxene, kyanite and monazite occur in these● ●
deposits .
The total stock of these eight types of heavy minerals
these seventeen deposits is 1761000 tons.

36. submitted by : shuvo das
id no : 14207101
Email: shuvo.das.imsf@gmail.com

37. Thanks to
everyone