Opportunities for Zinc Compound Recovery from Mining Influenced Water

摘要

The zinc value in mining influenced water (MIW) is lost when conventional alkaline water treatment process trains are employed for removal. Recovering the zinc value from MIW requires modifying the treatment sequence to produce a metal with a chemical form of value to a market/buyer. One market for zinc is the fertilizer industry, which requires feedstock that can be economically converted to zinc oxide or zinc sulfate.This paper examines the constraints that should be considered when determining the potential value of zinc in MIW. Contaminant specifications for zinc fertilizer include limits on arsenic, cadmium, chromium, mercury and lead, metals that can co-occur with zinc in MIW. Selective recovery of zinc from MIW in the oxy-hydroxide or carbonate form has the potential to provide a usable feedstock for fertilizer manufacture. Additional processing is required of zinc feedstock to produce a salable product.An evaluation of potential for zinc fertilizer feedstock recovery from the Nelson Tunnel drainage (Colorado, USA) is presented. The relative concentration of co-contaminants that may occur with zinc oxy-hydroxide or zinc carbonate precipitate formation is estimated. Low relative concentration of metal co-contaminants in MIW is an important factor in producing a zinc feedstock that can meet the acceptance specifications.