Effect of depressants in the selective flotation of scheelite and calcite using oxidized paraffin soap as collector

Calcite, in most cases, is the major gangue mineral found in scheelite ores. It is difficult to separate scheelite and calcite due to the similarities in their formation properties. In this study, it was found that scheelite and calcite can be floated using fatty-acid collector oxidized paraffin soap in the pH regions of 8-11 and 6-12, respectively. The effects of sodium hexametaphosphate (SHMP), tanning extract, starch and acidified water glass (AWG) as depressants of calcite have been studied. The AWG was the appropriate depressant without imposing obvious adverse effects on scheelite flotation. In order to prove the validity of the findings, flotation of both mixed mineral (1:1 scheelite:calcite) and real ore were conducted as well as zeta potential measurements.