Joint use of metal ion hydroxy complexes and organic polymers to depress pyrite and ash during coal flotation

Abstract

A novel system for the depression of pyrite and the ash-forming minerals has been developed. A metal ion, including but not restricted to Fe+2, is added to form a hydroxide coating on the pyrite or ash-forming minerals. A polymeric depressant is then added to attach to these resurfaced minerals. Nearly 200 flotation tests with 11 different coals indicate the effectiveness of this system. Many of the important process variables such as the coal source, frother-collector system, grind size and procedure, pH, metal ion, and depressant type and concentration have been studied.