Polymer blends for flocculation

摘要

Polymer flocculants are described comprising blends of high molecular weight polyethylene oxide and high molecular polyacrylamides. When introduced in desired amounts and with desired molecular weight ranges, excellent flocculation function is found that can be used to reduce polymer consumption to obtain a desired purity of clarified waste water. It has been found that the desirable polymer blends can be effectively added upstream from locations in which polyethylene oxide would generally be added so that the polymer blend can effectively mix with the slime flow to reduce or eliminate the need for excess polymer use to compensate for less effective mixing with the slime flow. Suitable waste treatment systems are described to provide for the delivery of the flocculants in the waste treatment process.

主权项

1. A method for removing waste from a waste stream comprising waste water from a mining operation, the method comprising:
combining a mixed aqueous solution of a flocculant composition with a waste stream flowing from a waste source to a thickening tank and comprising particulates to form settling flocculants, wherein the flocculant composition comprises polyethylene oxide polymer having a molecular weight of at least about 1 million g/mol and anionic polyacrylamide having an average molecular weight of at least about 15 million g/mol, wherein the flocculant composition is added to the waste stream at a dosage from about 1 part per million by weight to about 50 parts per million by weight of the waste water and wherein the mixed aqueous solution of the flocculant composition is effective to clarify the waste water to remove at least about 90 percent of solids initially present in the waste stream resulting in a clarified water flow; flowing the waste stream combined with the flocculant composition into the thickening tank; and draining concentrated tailings from the lower 20% of the thickening tank height, wherein the clarified water flow is removed from the top 40% of the thickening tank height.