Utilization of pyrogallol in flotation separation of scheelite from calcite

Scheelite is a typical tungsten-containing mineral and usually co-exists with calcite in deposits. The flotation separation of scheelite from calcite is a hard work in mineral processing. In this paper, pyrogallol, a by-product of humic acid decomposition was utilized as a depressant in flotation separation of scheelite from calcite. Flotation tests on singe mineral and mixed binary mineral were conducted. The results show that using pyrogallol as depressant can realize the flotation separation of scheelite from calcite by controlling pulp pH in 7.0–8.5. Zeta potential measurements and FTIR studies were performed to define the depression mechanism of pyrogallol on calcite. The results show that the pyrogallol depresses calcite flotation through complex adsorption and H bond adsorption on calcite surface.