| abstract |
Coal fines are recovered from an aqueous slurry which also contains shale as suspended fine solids by adding to the slurry a hydrophobic polymer such as a polybutadiene or a polyvinylether in a liquid organic carrier such as gas oil, diesel oil or kerosene, agitating the resulting mixture, introducing gas such as air into the mixture to form bubbles whereby flocs of coal fines formed are caused to float, and discarding the underlying slurry containing shale. To aid solution of the polymer a co-solvent, such as an aromatic solvent or a paraffinic solvent, compatible with the carrier may be used. The method is preferably carried out as a froth flotation in a froth flotation cell using a conventional frother such as methyl isobutyl carbinol or a mixture of polypropylene glycol ethers in addition to the polymer and carrier. |