In order to depress quartz activated by Zn(II) or Pb(II), sodium silicate
and sodium fluoride could not completely depress the activated
quartz, and also starch has little effect on the activated quartz.
Regarding sodium sulfide, SH, and CMC as depressants of activated
quartz, by using sodium sulfide and SH, the recovery of the quartz
activated by Zn(II) or Pb(II) plummets from 85 to 0%, but they have
also tangible negative effect on smithsonite recovery. CMC showed
the best results as depressant, with increasing CMC concentration,
the recovery of activated quartz has dropped down to 0%, whereas,
it does not have any impact on smithsonite recovery. Under these circumstances,
it can be claimed that CMC is an appropriate depressant
to depress quartz activated by Zn(II) or Pb(II) without exerting any
adverse influence on smithsonite flotation.