Process for concentrating ores

摘要

In the froth flotation of sulphide ores are used collectors consisting of one or more polysiloxanes emulsified with a surface-active nitrogen-containing organic compound. The polysiloxane preferably contains 3-10 siloxane units in a linear unbranched chain, and the emulsifier may be a quaternary alkyl ammonium salt such as dodecyl-(dimethyl)-benzyl-ammonium chloride, or the sodium salt of stearoyl-hydroxyethylamide sulphate. In the flotation of lead-zinc ores, galena may be initially floated out from an alkaline pulp, and then sphalerite may be floated out after acidification of the pulp and addition of copper sulphate. The addition of zinc sulphate to the pulp before the operation affords a better depression of sphalerite during the galena flotation. The example discloses the use of CH3Si[OSi(CH3)3]2 (CH2)17.CH3 as the polysiloxane and terpene alcohol as the frother.