利用电石渣制备针叶形碳酸钙的研究

Needle-like calcium carbonate synthesized by carbide residue

为有效利用电石渣资源,以电石渣为原料合成了针叶形碳酸钙。利用XRD、SEM等研究了电石渣的预处理方式、溶液的pH值对碳酸钙纯度和白度的影响,以及碳化反应温度、添加剂对针叶形碳酸钙形成的影响。结果表明:电石渣在105℃下干燥2h的方式进行预处理,且控制碳化反应溶液的pH>7时,可获得纯度>97%、白度>98的针叶形碳酸钙。碳化反应温度是影响针叶形碳酸钙形成的主要因素,合成针叶形碳酸钙的最佳碳化反应温度为80℃左右,其含量可达94%左右。添加剂MgCl2对针叶形碳酸钙晶体的长径比也有较大影响。利用工业副产物电石渣可以合成高纯度针叶形碳酸钙。

To recycle calcium carbide residue that was the waste by-product of industry, needle-like calcium carbonate was synthesized by calcium carbide residue. Effects of the pretreatment method of calcium carbide residue and the pH on the purity and the brightness of calcium carbonate, and the carbonization reaction temperature and the additive on the formation of needle-like aragonite, were investigated by XRD and SEM. The result shows that needle-like calcium carbonate has the purity above 97% and the brightness above 98, while calcium carbide residue was dried at 105℃ for 2h and the pH of carbonization reaction resolution was controlled above 7. The carbonization reaction temperature was the main effect on the formation of calcium carbonate, and the optimal carbonization reaction temperature was 80℃, at which the purity of needle-like calcium carbonate was above 94%. Magnesium chloride has great effect on the length-to-width ratio of needle-like calcium carbonate. High purity needle-like calcium carbonate can be synthesized by calcium carbide residue.