Abstract: The similar flotability of scheelite， fluorite， and calcite resulted in the separation difficult by flotation. The effect of sodium silicate on the flotation of scheelite by FTIR and the wettability change of the usual cleavage surface was revealed. A new collector， lead complexes of benzohydroxamicacid， was found to be selective for the separation of scheelite and calcium minerals with little sodium silicate， the collector can realize selective separation of scheelite from other calcium minerals. Hence a novel flotation process was developed for the recovery of refractory tungsten minerals， industricial application was conducted in Shizhuyuan Polymetallic Mine. The new floatation process is based on Pb-BHA ion collector， and the ratio and dosage method is adjusted， which realize the bulk flotation separation of wolframite and scheelite at normal temperature and replace the classical “Petrov's process” for scheelite-calcite-fluorite type ores. The disappearance or decreasing of sodium silicate contributed to improving the recovery of tungsten and the circulation of water and reagents.

Key words: Tungsten minerals, Flotation, Calciumminerals, Pb-BHA ion collector, Sodium silicate