Patent ID: 6042732
Filing Date: 2000-03-28
Classification: C02F

Abstract:
A method for dewatering coal tailings containing water, said method comprising the steps of:a. feeding said coal tailings to a thickener;b. contacting said coal tailings with an effective coagulating amount of a coagulant comprising a combination of a cationic polymer and a starch to reduce turbidity in said water, wherein said cationic polymer is formed from polymerization of one or more monomers selected from the group consisting of dimethylaminoethylacrylate methyl chloride quaternary salt, dimethylaminoethylacrylate benzyl chloride quaternary salt, dimethylaminoethylmethacrylate methyl chloride quaternary salt, dimethylaminoethylmethacrylate benzyl chloride quaternary salt, diallyldimethylammonium chloride and combinations thereof, and wherein the weight ratio of cationic polymer to starch in said combination is from about 99:1 to about 20:80;c. allowing said coal tailings to settle to the bottom of the thickener to obtain concentrated coal tailings;d. discharging said concentrated tailings from said thickener; ande. withdrawing clarified liquid from said thickener.