HELVETICA CHIMICA ACTA, vol.92, no.3, pp.502-513, 2009 (SCI-Expanded)
The effects of time, CO2-gas-injection pressure, and bulk temperature on the precipitation of Ca2+ ions as a precipitated calcium carbonate (PCC) from a dolomite leach solution were investigated. Precipitation periods from 1 to 7 min were examined, and experiments were run at CO2-injection pressures of 200 – 800 kPa. Effects of bulk temperature were studied in the range from 40 to 708, and recipitation rates of PCC were determined by measuring the Ca2ş concentrations in the initial and effluent solutions. Influences of these parameters on the subsequent incorporation of Mg2ş ions with the nprecipitate are discussed in detail. Kinetic analysis of the precipitation was performed by considering the rates as a function of CO2_ 3 -ion concentrations. Results obtained by this process clearly show that Ca2 ions in the solution can successfully be precipitated as a calcium carbonate product containing 54.70% of CaO and 0.77% MgO, at the rate of 2.01 mm h_