文献类型：会议论文

英文题名：Preparation of calcium carbonate and hydrogen chloride from distiller waste based on reactive extraction-crystallization process

作者：Li, Yunzhao[1];Song, Xingfu[1];Chen, Guilan[1];Sun, Ze[1];Xu, Yanxia[1];Yu, Jianguo[1]

机构：[1]E China Univ Sci & Technol, Sch Resources & Environm Engn, Natl Engn Res Ctr Integrated Utilizat Salt Lake R, Shanghai 200237, Peoples R China

会议论文集：23rd International Symposium on Chemical Reaction Engineering (ISCRE)

会议日期：SEP 07-10, 2014

会议地点：Bangkok, THAILAND

语种：英文

外文关键词：Distiller waste; N235; Reactive extraction-crystallization; Calcium carbonate

摘要：The distiller waste containing mainly calcium chloride (CaCl2) is being discharged in the Solvay process, and it has not been recycled comprehensively. In this study, a novel route for the treatment of the distiller waste was developed, in which CaCl2 solution was transformed into calcium carbonate and hydrogen chloride based on a reactive extraction-crystallization process using N235-isoamyl alcohol as the extraction system. Experimental results showed that the optimum conditions were 240 min as reaction time, 20 degrees C as the best temperature, 1.0 mol L-1 as initial concentration of CaCl2, 50% volume fraction of N235, 2:1 as the best phase ratio, and one-time feeding pattern. The conversion rate of CaCl2 was up to 75% under the optimized conditions; moreover, the concentration of H+ in organic phase was 0.70 mol L-1 and rhomibic calcite of high purity could be obtained. The products were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and thermogravimetry/differential scanning calorimetry. The extraction mechanism involved the ion-pair formation and the extraction complex R3N center dot HCl was determined by saturation method. The enthalpy change of the overall reaction Delta H was -36.47 kJ mol(-1), indicating that it was an exothermic reaction with the possibility of getting hindered at high temperature. (C) 2014 Elsevier B.V. All rights reserved.