Method for recovering scheelite from tungsten ores by flotation

In a flotation process for recovering scheelite by the flotation thereof from an aqueous pulp of low-grade tungsten ore containing calcium bearing minerals in addition to scheelite said process involving the addition to the aqueous ore pulp of a carbonate alkalizing agent and a dispersant followed by an anionic collector, the improvement which comprises adding to the ore pulp, prior to the addition of the anionic collector and the dispersant, if added as a silicate dispersant, an amount of calcium oxide sufficient to raise the pH of the aqueous media of the pulp by 0.1 pH unit and form a precipitate of calcium upon conditioning the pulp by agitation sufficient to suspend substantially all of the solids in the pulp in the aqueous pulp media, said conditioning being for at least about five minutes and the pH of the ore pulp, prior to the addition of anionic collector being in the range of about 9-12.