针状纳米活性碳酸钙合成改性一体化的研究

Study on the Integration of Preparation and Modification of Acicular Nanometer Active Calcium Carbonate

以电石渣为原料制备纳米活性碳酸钙,不仅能够将电石渣进行循环利用,减少环境污染,同时生成的针状纳米活性碳酸钙,市场需求量大,经济价值高。本研究以电石渣和氯化铵为初始原料首先制备得到CaCl2,然后采用复分解法与(NH4)2CO3反应,选用合适的改性剂,将针状纳米活性碳酸钙合成和改性一体化完成进行。实验综合考察了溶液浓度、改性剂用量、反应温度、滴加速度等反应条件对碳酸钙形貌和粒径的影响,并设计正交实验进行优化,得出最佳反应条件:CaCl2和(NH4)2CO3溶液浓度0.15mol/L,反应温度65℃,改性剂用量1.25%,滴加速度3mL/min。通过验证实验,最终制得平均粒径55nm,长径比15.35,活化度98.86%,吸油值43.75g/100g的针状纳米活性碳酸钙。

For the cyclic utilization of carbide slag, this experiment prepared CaCl2 with carbide slag and NH4Cl as the raw mate- rial in the first, then used the double decomposition method and chose the appropriate modifier to synthesize and modify acicular nanometer active calcium carbonate with CaCl2 and（NH4）2 CO3. Various reaction conditions, such as the concentration of sol u tions,dosage of modifier,reaction temperature,dropping speed were investigated. Then we designed orthogonal experiment for the these factors, and obtained the optimum reaction conditions： the concentration of CaCl2 and（NH4）2CO3 solution is 0. 15 mol/L, the dosage of modifier is 1.25%, the reaction temperature is 65℃, the dropping speed is 3 mL/min. Acieular nanometer active calcium carbonate was prepared by verification test with the size of 55 nm, the ratio of length to diameter of 15.35, the ac- tivation degree of 98.86% ,oil absorption value of 43.75 g/100g. Nanometer active calcium carbonate was prepared by carbide slag as the raw material, which realizes the cyclic utilization of carbide slag, reduces pollution on environment and offers high e conomic benefit.