CARBONATION OF WOLLASTONITE USING SUPERCRITICAL CARBON DIOXIDE

摘要

The feasibility of a CO_2 disposal method based on combining CO_2 chemically with silicate rocks was tested in this experiment. The process utilized a stirred batch reactor in which supercritical CO_2 was absorbed into a wollastonite (CaSiO_3) slurry to cause the dissolution of mineral and then the precipitation of calcium carbonate. The amount of CO_2 fixed in the solid phase was determined by a thermogravimetric analysis. The effect of operating variables, including reaction temperature, mineral particle size, and CO_2 pressure on the conversion of wollastonite were investigated. A high conversion of 82% for the wollastonite of 40.5μm mean size was achieved when the sample reacted at 80°C and 8.6 MPa for 6 h.