化学沉淀法制备纳米乳酸钙

以乳酸与氢氧化钙为原料，采用化学沉淀法制备了纳米乳酸钙，研究了影响所制备乳酸钙粒径的因素，采用粒度分析仪、分光光度计、XRD及TEM对粉体进行表征。研究结果表明：采用化学沉淀法制备纳米乳酸钙需在乳酸钙溶液接近饱和时，过滤除去未反应的氢氧化钙，抑制目标产物二次成核；向滤液中加入适量的乙醇，促进成核，抑制晶体的生长，并提高纳米粉体的分散性；采用化学沉淀法适宜的工艺条件制备乳酸钙粉体平均粒径分别可达52．3nm，粒度分布窄，乳酸钙纯度达到99％以上，质量符合食品级乳酸钙的国家标准（GB6226-86中砷及重金属含量）要求。

Preparation of nanometer calcium lactate via chemical precipitation method

Nano calcium lactate was prepared by chemical precipitation procedure and lactic acid and calcium hydroxide were selected as raw materials in the method. The influencing factors were studied, and the prepared samples were characterized by multi-angle sub-micro particle size analyzer, spectrophotometer, XRD and TEM. The experimental results showed that when the nano particles were prepared in terms of chemical precipitation method, it was necessary to make calcium lactate solution close to super-saturation solution with the aim of inhibiting the secondary nucleate, and filtrate unreacted calcium hydroxide from the mother liquor; then, add the proper quantity of ethanol into the filtration liquor so as to increase the nucleation rate and control the crystal growth, thus increase the dispersity of nanopowder. The average particle size of prepared calcium lactate powders using the chemical precipitation method was 52.3 nm with narrow crystal size distribution; the purity of calcium lactate was up to 99 %. The specification for the samples obtained by the method met the requirements stipulated in the standard of calcium lactate with food grade （GB 6226--86 arsenic and heavy metals）.