Feasibility of concentrating potassium minerals from Verdete ore by cell flotation

A silicate ore with K2O content above 10%, found in the central region of Minas Gerais (Brazil), called Verdete, was floated in flotation cell. The goal was to evaluate the flotation behaviour of the ore constituents (glauconite, muscovite, K-feldspar and quartz) relative to the use of different collectors (fatty acid soap obtained from rice oil, amine and oleic acid) and depressors (gelatinized cornstarch and sodium silicate). Flotation of the calcination products of Verdete with MgCl2 and CaCl2 were also evaluated. Mass recovery of flotation carried out with Verdete reached a maximum of 53% when amine and sodium silicate were used as collector and depressant, respectively. Mass recovery was directly proportional to collector dosage, and was also influenced by the type of depressor. Calcination of Verdete with MgCl2?xH2O partially consumed the micas and generated MgO. Flotation of this calcination product concentrated MgO in the floated fraction, reaching 93% when oleic acid was used as collector.