US4436618A — Recovery of coal from coal handling operations

Claim 1

Independent Claim 203 words

In a method of recovering coal from a particulate coal bearing slurry comprising agitating said slurry in the presence of an appropriate hydrophobic liquid and subsequently separating coal from the slurry, the improvement comprising substantially reducing the time to recover coal from said slurry liquid by forming said particulate coal into agglomerate pellets of dimensions to be readily separated from said slurry liquid by introducing the slurry to the inlet of a centrifugal turbulent flow slurry pump having a pumping chamber, introducing said hydrophobic liquid into said pumping chamber simultaneously with said slurry in a quantity sufficient to achieve substantially intimate contact between said hydrophobic liquid and said coal particles, passing said slurry and said hydrophobic liquid through said pump in a single pass to subject the coal particles to extreme turbulence within the pumping chamber to rapidly coat the coal particles with the hydrophobic liquid and to repeatedly bring the coal particles into contact with other coal particles in the pumping chamber to agglomerate and pelletize the coal particles in the pumping chamber, whereby the coal may be readily separated from the slurry liquid and whereby the time taken for the recovery of the coal from the slurry liquid is substantially reduced.

Claim 2

Dependent Claim 203 words

In a method of recovering coal from a particulate coal bearing slurry comprising agitating said slurry in the presence of an appropriate hydrophobic liquid and subsequently separating coal from the slurry, the improvement comprising substantially reducing the time to recover coal from said slurry liquid by forming said particulate coal into agglomerate pellets of dimensions to be readily separated from said slurry liquid by introducing the slurry to the inlet of a centrifugal turbulent flow slurry pump having a pumping chamber, introducing said hydrophobic liquid into said pumping chamber simultaneously with said slurry in a quantity sufficient to achieve substantially intimate contact between said hydrophobic liquid and said coal particles, passing said slurry and said hydrophobic liquid through said pump in a single pass to subject the coal particles to extreme turbulence within the pumping chamber to rapidly coat the coal particles with the hydrophobic liquid and to repeatedly bring the coal particles into contact with other coal particles in the pumping chamber to agglomerate and pelletize the coal particles in the pumping chamber, whereby the coal may be readily separated from the slurry liquid and whereby the time taken for the recovery of the coal from the slurry liquid is substantially reduced.

Claim 3

Dependent Claim 43 words

The coal recovery method of claim 1, further comprising the step of additionally agitating the slurry before separation of said coal to achieve additional contact between the agglomerated coal particles produced by the agitation within said pump chamber whereby larger agglomerates are produced.

Claim 4

Dependent Claim 25 words

The coal recovery method of claim 2, wherein said further agitation is achieved by an agitating means in a pipeline connected to the pump outlet.

Claim 5

Dependent Claim 17 words

The coal recovery method of claim 3, wherein said agitating means comprises an in-line flow promoting device.

Claim 6

Dependent Claim 37 words

The coal recovery method of claim 4, wherein said flow promoting device causes the coal containing slurry to move in an helical path thereby causing the coal particles to contact each other to form said larger agglomerates.

Claim 7

Dependent Claim 24 words

The coal recovery method of claim 1, wherein said hydrophobic liquid is introduced in the form of an unstable emulsion of oil and water.

Claim 8

Dependent Claim 31 words

The coal recovery method of claim 1, wherein said slurry and said hydrophobic liquid are subjected to shear rates of about 200 to about 3500 s -1 within said pumping chamber.

Claim 9

Independent Claim 199 words

A system for recovering coal in the form of pellets from a particulate coal bearing slurry comprising (a) a pipeline for carrying the slurry; (b) a centrifugal turbulent flow slurry pump having a pumping chamber connected to said pipeline for pumping said slurry; (c) feed means for introducing an appropriate hydrophobic liquid to the pumping chamber of said pump simultaneously with the introduction of said slurry into said pumping chamber in a metered quantity sufficient to achieve substantially intimate contact between the hydrophobic liquid and the coal particles in said slurry, said pump means and said feed means co-operating to pass said slurry and said hydrophobic liquid through said pump in a single pass and to subject the coal particles to extreme turbulence within the pumping chamber to rapidly coat the coal particles with the hydrophobic liquid and to repeatedly bring the coal particles into contact with other coal particles in the pumping chamber to agglomerate and pelletize the coal particles in the pumping chamber; and (d) separating means for separating the pelletized coal particles from said slurry upon discharge from said pump whereby the time taken for the recovery of the coal from said slurry is substantially reduced.

Claim 10

Independent Claim 199 words

A system for recovering coal in the form of pellets from a particulate coal bearing slurry comprising (a) a pipeline for carrying the slurry; (b) a centrifugal turbulent flow slurry pump having a pumping chamber connected to said pipeline for pumping said slurry; (c) feed means for introducing an appropriate hydrophobic liquid to the pumping chamber of said pump simultaneously with the introduction of said slurry into said pumping chamber in a metered quantity sufficient to achieve substantially intimate contact between the hydrophobic liquid and the coal particles in said slurry, said pump means and said feed means co-operating to pass said slurry and said hydrophobic liquid through said pump in a single pass and to subject the coal particles to extreme turbulence within the pumping chamber to rapidly coat the coal particles with the hydrophobic liquid and to repeatedly bring the coal particles into contact with other coal particles in the pumping chamber to agglomerate and pelletize the coal particles in the pumping chamber; and (d) separating means for separating the pelletized coal particles from said slurry upon discharge from said pump whereby the time taken for the recovery of the coal from said slurry is substantially reduced.

Claim 11

Dependent Claim 43 words

The coal recovery system of claim 8, further comprising means for additionally agitating the slurry before separation of said coal therefrom to achieve additional contact between the agglomerated coal particles produced by the agitation within said pump chamber whereby larger agglomerates are produced.

Claim 12

Dependent Claim 28 words

The coal recovery system of claim 9, wherein said means for additionally agitating said slurry comprises agitating means within a pipeline connecting said pump and said separating means.

Claim 13

Dependent Claim 61 words

The coal recovery system of claim 10, wherein said means for additionally agitating said slurry comprises a section of said pipeline downstream of said pump, said section of pipeline being in the form of a helix having a pitch substantially equivalent to twice the diameter of said pipeline and a length substantially equivalent to six times the diameter of said pipeline.

Claim 14

Dependent Claim 35 words

The coal recovery system of claim 8, wherein said system further comprises means for producing an unstable emulsion of oil and water for introduction to said pump chamber simultaneously with the introduction of said slurry.

Claim 15

Dependent Claim 29 words

The coal recovery system of claim 8, wherein said pump is such as to produce shear rates of about 200 to about 3500 s -1 in said pump chamber.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1987-03-13	1987-09-12	1988-03-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1991-03-13	1991-09-12	1992-03-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1995-03-13	1995-09-12	1996-03-13	$7700.00	Window Closed / Lapsed

Recovery of coal from coal handling operations

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