Coal flotation process
AssigneeFording Coal Limited
InventorsColin J. McKenny, Brian W. Raymond
Life of this patent
Estimating the term…
Abstract
A process for the flotation of particles of lignitic coal, subbituminous coal or oxidized bituminous coal contained within a slurry of coal and gangue, comprising the steps of dispersing a surfactant throughout the slurry, first conditioning the slurry such that the surfaces of the particles of coal are selectively coated by the surfactant to produce activated particles of coal, dispersing an oil throughout the slurry, second conditioning the slurry such that the surfaces of the activated particles of coal are selectively coated by the oil to produce oiled particles of coal, and floating the oiled particles of coal on the surface of the slurry for separation from the slurry and gangue.
Claims48
A process for selectively floating particles of lignitic coal, subbituminous coal or oxidized bituminous coal contained within a slurry of coal and gangue, comprising the following steps in the sequence set forth:
- (a) dispersing a quantity of a surfactant throughout the slurry;
- (b) first conditioning the slurry in the presence of said quantity of surfactant by mixing or agitating such that the surfaces of the particles of coal are selectively coated by the surfactant to produce more oleophilic activated particles of coal;
- (c) dispersing a quantity of an oil selected from the group consisting of heavy oil and bunker C oil throughout the first conditioned slurry containing the surfactant coated, more oleophilic, activated particles of coal;
- (d) second conditioning the first conditioned slurry in the presence of said quantity oil by mixing or agitation such that the surfaces of the surfactant coated, more oleophilic , activated particles of coal are selectively coated by the oil to produce oiled particles of coal;
- and
- (e) subjecting the second conditioned slurry to selective flotation in the presence of gas bubbles to selectively float the oiled particles of coal on the surface of the slurry for separation from the slurry and the gangue;
- where the surfactant is a substance that will selectively adhere to the coal and not the gangue, and will cause the coal to accept a coating of the oil.
Dependencies are inferred from the claim text.