Flocculation of coal particles and coal slimes

摘要

An improved process for flocculating and clarifying colloidal coal slurries comprises contacting a coal liquor with a water-soluble, low molecular weight polymer with high anionic character; an inorganic coflocculant; and a water-soluble high molecular weight polymer with low anionic character. The low molecular weight polymer contains at least 50 mole percent nonionic monomer. The process allows coal liquor clarification to be performed using low total polymer dosages.