Mineralogical study of original and crushed zinc ores as well as mill products was made in order to find out the cause of low-grade concentrate and the scheme of raising its grade. Low-grade concentrate is due to 1) the abundance of other independent ...
Mineralogical study of original and crushed zinc ores as well as mill products was made in order to find out the cause of low-grade concentrate and the scheme of raising its grade. Low-grade concentrate is due to 1) the abundance of other independent sulfides (arsenopyrite, pyrrhotite, chalcopyrite, stannite) and silicate (quartz) in the zinc concentrate, 2) the presence of composite grains of sphalerite and other sulfides or silicate, 3) the presence of a lot of very fine-grained particle of stannite and chalcopyrite within the sphalerite grains, and 4) the high content of iron in sphalerite. It is proposed that further crushing and other appropriate processing should be made in order to increase the grade of zinc concentrate.