Patent ID: 7244361

Claim:
A metals/minerals recovery and waste treatment process comprising a main separation stage in which a metal/mineral-bearing ore is slurried with water and separated into an enriched fraction and an aqueous metal/mineral waste fraction, and a waste sedimentation stage in which the aqueous metal/mineral waste fraction is sedimented in one or more settling lagoons to provide a thickened sediment layer and supernatant; and the waste sedimentation stage comprises feeding the aqueous metal/mineral waste into a Solids Contact Vessel or other flocculating chamber, wherein the aqueous metal/mineral waste fraction is diluted with water containing a flocculant at more than one concentration, one of which concentrations is at least 10 times higher than the other, within said Solids Contact Vessel or other flocculating chamber, wherein said concentration of flocculant range from 0.05 to 0.0001% by weight, and said flocculant has an intrinsic viscosity of at least 4 dl/g, flocculating the diluted aqueous waste, and sedimenting the diluted and flocculated aqueous waste to provide a liquid supernatant layer and a pumpable thickened sediment layer in a settling basin.