AN IMPROVED TECHNOLOGY FOR TREATMENT OF COAL TO
MINIMISE IMPREGNATEP IMPURITIES BY ULTRASOUNP ENEMY
ADAPTABLE IN MINERAL BENEF1CIATION
HELD OF THE INVENTION
The present invention relates to a technology of treating coal for reduction
of impurities in mineral beneficiation of mined product. More particularly,
the present invention relates to development of a technology for treatment
of coal to minimise impregnated impurities in coal and coal-like materials by
ultrasound energy adaptable in mineral beneficiation kind of activities.
BACK GROUND OF THE PRESENT INVENITON
The main source of many valuable minerals like Iron, Copper, Aluminium
etc are from their respective parent ores likes haematite, chalco Pyride,
Bauxite, from which they are extracted by successive steps of beneficiation
process like crushing, classifying and washing. Ore dressing and washing is
a process wherein the valuable minerals are separated from gangue on the
basis of their differential specific gravity.
It is essential to any process of mineral seperation lies on specific gravity
difference which in turn make the physical seperation of the valuable
materials and undesirable contaminated impurities. Coal washing is one of

such example of beneficiation where a seperation based on specific gravity
difference between the valuable mineral and the undesired impurities.
A country like India where coal is abundantly available and acts as a fuel
and one of the main resources of energy, comprising mostly of carbon and
small percentages of hydrogen, sulpher and ash. Besides that coal is also
adaptable as a source of energy in power plant, and steel making operation
is steel plant. But the practical problem involved in both the cases are
when coal is burnt in thermal power plant, due to presence of sulpher and
ash in coal emits noxious sulpher dioxide and ash from the boiler's chimney
and starts to pollute the environment. Ash enters into the atmosphere as
small particles and spread over the adjacent area.
In the coal fields region, a conventional coal mining operations are carried
out by traditional refining of useful coal by washing it from less valuable
sand and clay, although fine particles of coal are often agglomerated with
the residues produced by coal washing processes, sulpher is also washed
out from coal by conventional coal washing methods to a large extent.
However, the existing method is not efficient on a large scale. Only a
certain small portion of mined coal can be sufficiently upgraded by only
conventional washing. No significant commercial process is yet available
for removing substantial amount of sulpher from coal.

To overcome the adversity of prior Act, the present invention emphasize to
develop towards improving the washing process by better seperation
brought about by the efficient application of ultrasound energy to discard
the undesirable impurities from coal. Further more, the present invention
also reduces the amount of phosphorus, volatile matter, gangue materials
contaminated in coal or coal like material by improve washing process. As
a result, the recovery of useful coal is improved and the ability of coal
product to shed water is increased.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to propose a method for
treatment of coal to minimize impregnated impurities in coal and coal like
material by ultra sound energy adaptable in mineral beneficiation which
eliminates the disadvantages of prior Art.
Another object of the present invention is to propose a method for
treatment of coal to minimize impregnated impurities in coal and coal like
material by ultrasound energy adaptable in mineral beneficiation which
provides effective and economic process for beneficiating crushed or
granulated coal and coal fines by reducing impurities like Ash, Sulpher,
Phosphorus, Volatile matter, gangue.

A still another object of the present invention is to propose a method for
treatment of coal to minimize impregnated impurities in coal and coal like
material by ultrasound energy adaptable in mineral beneflciation which can
be adoptable to separate heavier and more abrasive materials than raw
coal.
An yet still another object of the present invention is to propose a method
for treatment of coal to minimize impregnated impurities in coal and coal
like material by ultrasound energy adaptable in mineral beneflciation which
minimises the abrasive action of slurry on the apparatus.
A further object of the present invention is to propose a method for
treatment of coal to minimize impregnated impurities in coal and coal like
material by ultrasound energy adaptable in mineral beneflciation which
decreases the consumption of flocculants by 80% to 90% without adversely
affecting the operating result.
A still further object of the present invention is to propose a method for
treatment of coal to minimize impregnated impurities in coal and coal like
material by ultrasound energy adaptable in mineral beneflciation which
generates self compaction of scrubbed fine particles, an impeded air
bubbles, gel particles or other foreign coatings which leads to rapid settling
and yields denser filter cake in sludge layer.

particle surfaces are cleaned in this manner. In all cases, the clarification
of the pond water is greatly improved and in some cases the settling rates
for the fines are increased as much as ten times.
Chemical additives such as flocculating agents are made significantly more
efficient by these processes. With the processes of this invention, the
normal amounts of flocculants may be reduced by as much as 80% to 90%
without adversely affecting the operating results.

WE CLAIM
1. An improved method for treatment of coal to minimize impregnated impurities in
coal by ultrasound energy adaptable in mineral beneficiation comprises:
- a coal slurry containing coal and water mixture in the weight ratio 1:10;
- an ultrasound transducer excites the coal slurry in a frequency of 22 kHz
to cause reduction of its impurities like ash, sulpher, phosphorus, gangue
material from coal; and
- a physically separating device as cyclone separators or vibrating screens
or centrifuge separator or spiral separator to separate and recover coal
with reduces ash, sulpher coal with reduced ash, sulpher, phosphorus,
volatile matter, gangue content.

2. The method as claimed in claim 1 wherein the coal is first crushed and sized
greater than 2 mm and lesser than 10 mm.
3. The method as claimed in claim 1 wherein the temperature of the slurry is
maintained at room temperature.

4. The method as claimed in claim 1 wherein the pressure of the slurry is
maintained normal pressure.
5. The method as claimed in claim 1 wherein the power applied to the ultrasonic
vibrator is 40 watt/litre.
6. The method as claimed in claim 1 wherein the time for ultrasound excitement of
coal slurry is 4-30 seconds.

The present invention relates to an improved method for treatment of coal to minimize
impregnated impurities in coal by ultrasound energy adaptable in mineral beneficiation
comprises a coal slurry containing coal and water mixture in the weight ratio 1:10 and
an ultrasound transducer excites the coal slurry in a frequency of 22 kHz to cause
reduction of its impurities like ash, sulpher, phosphorus, gangue material from coal and
a physically separating device as cyclone separators or vibrating screens or centrifuge
separator or spiral separator to separate and recover coal with reduces ash, sulpher
coal with reduced ash, sulpher, phosphorus, volatile matter, gangue content.