CO2 UPTAKE USING NEUTRALIZATION PROCESS OF MINE DRAINAGE

Among various technologies for capturing and storing CO₂, the mineral carbonation technology stores CO₂ by reacting natural minerals and industrial byproducts containing a lot of Ca or Mg with CO₂ and resultantly forming carbonate minerals. As a method of capturing CO₂, this study utilized the neutralization process of mine drainage using hydrated lime. The neutralization-carbonation treatment of mine drainage was performed by input of hydrated lime followed by agitation to increase pH sufficiently and then injection of CO₂ to react with dissolved Ca to form calcium carbonate precipitates. According to the results of preliminary tests for highly metal concentrated synthetic mine drainage, field mine drainage samples were treated by the neutralization-carbonation processes with nearly optimal CO₂ injection rate and resultantly getting a reasonable efficiency of CO₂ immobilization. Also metal redissolution from sludge did not take place during the injection of CO₂, which suggests that the neutralization-carbonation processes can be adopted to treat mine drainage and uptake CO₂ efficiently.