ELECTROSTATIC FELDSPAR/QUARTZ SEPARATION WITHOUT HYDROFLUORIC ACID REDUCES POLLUTION

摘要

Years ago the electrostatic drum separators are replaced by a freefall separator. The setting and maintenance of the freefall separator is easier and it is cheaper to manufacture. It is somewhat more sensitive to the grain size distribution, compared to the drum separator. Moreover we still need an activation by hydrofluoric acid and elevated temperature. Looking for a possibility to avoid the hydrofluoric acid, to reduce pollution and the environmental risk, it was proposed to activate the feed with other organic and inorganic reagents. Tests with different polyelectrolytes are carried out. Just as much we studied the effect of pH, temperature, polarity, voltage, the material of the feeder, the electrode shape and configuration and the splitter settings. The target was a feldspar concentrate with >80 percent feldspar and a quartz product with <5 percent feldspar. The feed grain size was 0.1 mm to 0.5 mm. The latest results are a feldspar concentrate with 85 percent feldspar grade and 27 percent wt and a quartz product with 4.4 percent feldspar grade and 40% wt of the feed.