An Increase in Process Characteristics of Flotation of Low-Grade Fine-Disseminated Scheelite Ores

Abstract

The results of investigations into increasing the contrast of process properties of calcite and scheelite due to the combined application of water glass with salts such as sulfates of aluminum, zinc, iron, magnesium; mixtures of water glass and calcium chloride; sodium carboxymethyl cellulose (CMC); combinations of sodium oleate with low-polar compounds (neonol and fatty iso-alcohols); and data on the ultrasonic treatment of the liquid phase and oleate are described. The lowest recovery of calcite during the flotation of a monomineral calcite fraction in the Hallimond tube is attained when jointly using salts of iron(II) and water glass (3(4) : 1). The joint application of water glass and CaCl₂ during the flotation of the low-grade scheelite ore with a high carbonate modulus using tap water lowers the calcite flotability. When using recycled water, adding calcium chloride to water glass leads to a certain increase in the yield of the rough concentrate (from 13.8 to 14.1%) with a significant decrease in the recovery of WO₃ into the final selection concentrate of scheelite (from 72.7 to 53.3%) and worsens the concentrate quality. The replacement of water glass by CMC showed no satisfactory results. The ultrasonic treatment of the pulp, liquid phase, and collector leads to a certain increase in calcite flotation activity, possibly due to an increase in the liquid phase temperature and in the fraction of the ionic form of oleate. The use of neonols in the reagent flotation mode of the scheelite-containing ore with a high carbonate modulus does not confirm a decrease in the flotation activity of calcite formed when studying monomineral calcite fractions, in contrast with fatty iso-alcohols, which make it possible to fabricate the higher quality concentrates in the selection cycle when compared with one oleate.