Preventing Chromium Leaching from Waste Slag Exposed to Simulated Acid Precipitation: A Laboratory Study

摘要

The Bureau of Mines tested chromium-bearing waste slags from industrial stainless steel and other chrome alloy operations to determine their chromium leachability characteristics under acid precipitation conditions and to devise measures to prevent any pollution originating from this source. Addition of magnesium silicates to molten slag to fix the chromium in the MgO:Cr2O3 form was successful in preventing chromium leaching in simulated acid rain solutions. Experiments showed olivine and waste taconite tailings were suitable for this purpose. Olivine addition to a waste slag having a composition vulnerable to leaching (CaO:SiO2 > 2) reduced the chromium leachability more than 80 pct.