INFLUENCE OF STICKY RICE AND ANIONIC POLYACRYLAMIDE ON THE CRYSTALLIZATION OF CALCIUM CARBONATE IN CHINESE ORGANIC SANHETU

Abstract

The crystallization of calcium carbonate ( CaCO 3) in soil controlled by natural organic material was considered a very important reason to enhance the property of ancient Chinese organic Sanhetu (COS), but how the organic material affected the crystallization of CaCO 3 in COS is still unclear. In this paper, a natural organic material (sticky rice, SR) and a synthetic organic material (anionic polyacrylamide, APAM) were selected as additives to investigate their effect on the crystallization of CaCO 3. The experimental results showed that the morphology and size of CaCO 3 crystals could be affected by the concentration of additives and reaction time, while only the size of CaCO 3 crystals could be affected by the concentration of reactant. Although the morphology and size of CaCO 3 crystals varied greatly with the variation of additive concentration, reactant concentration and reaction time, the polymorph of CaCO 3 crystals were always calcite, according to SEM/EDX, XRD and FTIR analyses. This study may help us to better understand the mechanism of the influence of organic materials on CaCO 3 crystallization and properties of COS.