Abstract:Flocculation settling test was conducted for various slurries in zinc hydrometallurgy. The test included neutral leaching, low acid leaching, reduction leaching of residues, and iron removal with hematite precipitation. Effects of molecular structure, molecular weight, preparation concentration, dosage and feeding method of flocculant, and temperature, pH value, solid content and colloid content of slurry on flocculation settling were comprehensively analyzed. Flocculants are selected according to properties of pulp. Proper controlling measurements are adopted to optimize flocculation and sedimentation of slurry and achieve good liquid-solid separation and economic benefits.