METHODS AND SYSTEMS USING ELECTROCHEMICAL CELLS FOR PROCESSING METAL SULFATE COMPOUNDS FROM MINE WASTE AND SEQUESTERING CO2

摘要

Systems and methods are provided for processing metal sulfate compounds and sequestering CO2. These systems and processes involve one or more electrochemical cells for producing an alkali-containing catholyte and involve a CO2 absorption reactor operatively connected to the electrochemical cell and to a CO2 source. The CO2 absorption reactor receives the alkali-containing catholyte and CO2 gas for forming an alkaline carbonate solution. The alkaline carbonate solution is directed to a vessel where it reacts with an acidic sulfate solution comprising metal ions resulting in precipitation of solid metal carbonate compounds. The acidic sulfate solution may comprise sulfide leachates from acid mine drainage, sulfide mine tailings and/or reacted pyrite concentrate. The acidic sulfate solution may be circulated through an optional SO2 reduction reactor prior to reaction in the vessel. The SO2 reduction reactor reduces trivalent metal compounds present in the acidic sulfate solution to divalent metal compounds.

主权项

1. A system for processing metal sulfate compounds and sequestering CO2, comprising:
an electrochemical cell producing an alkali-containing catholyte; a CO2 absorption reactor operatively connected to said electrochemical cell and to a source of CO2, said CO2 absorption reactor receiving said alkali-containing catholyte and said CO2 for forming an alkaline carbonate solution; and a vessel for receiving an acidic solution containing metal sulfate compounds and for receiving said alkaline carbonate solution, said vessel allowing precipitation of solid metal carbonate compounds.