Mineralizing CO2 as MgCO3 center dot 3H(2)O Using Abandoned MgCl2 Based on a Coupled Reaction-Extraction-Alcohol Precipitation Process

摘要

A novel coupled reaction-extraction-alcohol precipitation process was proposed to mineralize CO2 as MgCO3 center dot 3H(2)O directly by abandoned MgCl2. Rod-like crystal MgCO3 center dot 3H(2)O was obtained, and the conversion rate of MgCl2 increased sharply by using this novel coupled reaction-extraction-alcohol precipitation process. The effect of an added C1-C3 alcohol precipitation agent on the conversion rate of MgCl2 was in the following order: ethanol > isopropanol > n-propanol > methanol. Moreover, the optimal conditions for the highest conversion rate of MgCl2 by single-factor experiments were obtained as follows: initial concentration of MgCl2 solution is 2 mol.L-1, volume ratio of ethanol and aqueous phase is 2, mole ratio of N235 and aqueous phase is 2, volume ratio of diluent and N235 is 0.5, with a stirring rate of 300 r.min(-1) at 298.15 K and at atmospheric pressure.