title: Recovery of calcium carbonate from waste gypsum and utilization for remediation of acid mine drainage from coal mines.
abstract: The recovery of calcium carbonate from waste gypsum (a waste product of the reverse osmosis (RO) desalination process) was tested using sodium carbonate. Batch recovery of calcium carbonate from waste gypsum slurries by reacting with sodium carbonate under ambient conditions was used to assess the technical feasibility of CaCO(3) recovery and its use for pre-treatment of acid mine drainage (AMD) from coal mines. The effect of key process parameters, such as the slurry concentration (%) and the molar ratio of sodium carbonate to gypsum were considered. It was observed that batch waste gypsum conversion significantly increased with decrease in the slurry concentration or increase in the molar ratio of sodium carbonate to gypsum. The CaCO(3) recovered from the bench-scale batch reactor demonstrated effective neutralization ability during AMD pre-treatment compared with commercial laboratory grade CaCO(3).
authors: Council for Scientific and Industrial Research, Natural Resources and the Environment, Meiring Naude, Brummeria, Pretoria, South Africa. jmulopo@csir.co.za
authors: J
authors: J
authors: Mulopo
authors: V
authors: V
authors: Radebe
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D002133:Calcium Sulfate / Q000737:chemistry*; D003031:Coal; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis*; D008906:Mining; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D003031:Coal; D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D002119:Calcium Carbonate; D002133:Calcium Sulfate