Removal of copper and zinc species from Bayer process liquor by filtration

摘要

A Bayer process solution is filtered through a bed of particles of a granular substance containing Fe.sub.2 O.sub.3 to remove copper and zinc species from the solution. The particles preferably have an Fe.sub.2 O. sub.3 content of about 40 to 100% by weight. For more effective removal of zinc, the particles are coated with a metal sulfide, preferably zinc sulfide.