Study On Morphogenesis Of Calcium Carbonate

There is plentiful Calcium ore in nature, most of which can be used to prepared for industrial grade calcium carbonate through a simple process. Since the last century, calcium carbonate had become a kind of important inorganic chemicals. As early as 1850, Europeans invented the method of industrial production of calcium carbonate. After 160 years, the production of calcium carbonate has been developed into a huge industry, of which market worth is billions of dollars at present. Typically, the calcium carbonate is used as filler and reinforcing materials in rubber, plastics, inks, food, paper, paint, and medicine etc. which are closely related to human life. In recent years, the extreme demand for high quality calcium carbonate products increases year by year, which are mainly a variety of special crystal form of calcium carbonate products. The morphologies of calcium carbonate has been studied in Europe, the United States and many other countries.In this paper, a series of calcium carbonate with different morphologies are prepared in a bench-scale batch reactor by adding crystal-controlling additives. Three kinds of CaCO3 with different morphologies, including cube CaCO3 with the size of 50nm, chain CaCO3 with the size of 50nm~100nm and 100nm~300nm, and sphere CaCO3 with the size of 30nm~50nm,were synthesized under the reaction temperature of 15℃~20℃, calcium hydroxide concentration of 130g/L, gas flow of CO2 of 5.55L/h, stirring speed of 200rpm and different amount of additives. Spindle-shaped calcium carbonate with size of 0.5μm~1μm was prepared under 30℃and 0.05% additive of A or B. Cube CaCO3 with size of 0.2μm~0.8μm was synthesized under 70℃and the amount of crystal-controlling additive A bellow 0.05%.Based on the bench-scale experiments, pilot-scale experiments were also made in this stusy. spindle-shaped , sphere and needle-like CaCO3 were synthesized under initial temperature of 41℃and the amount of additive A below 0.05%, 0.2% and 2.0% respectively in the pilot experiments. The results also showed that additive and reaction temperature are the important factors for the morphogenesis of calcium carbonate.