新型脱硅剂水合碳铁酸钙合成过程的光谱学研究  

Spectroscopy Research on Synthesis of New Desilication Reagent-Calcium Hydroferrocarbonate

作　　者：洪涛[1,2] 郑诗礼[2] 张懿[2] 孟令媛[1] 

机构地区：[1]西安建筑科技大学,陕西西安710055 [2]中国科学院过程工程研究所,北京100080

出　　处：《光谱学与光谱分析》2009年第2期418-422,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金重点项目(50234040);国家“863”项目(2005AA647010)资助

摘　　要：亚熔盐溶出一水硬铝石型铝土矿过程中需在高浓介质条件下脱除二氧化硅杂质,研究采用合成水合碳铁酸钙做为脱硅剂;因水合碳铁酸钙合成过程中会有碳酸钙、氢氧化钙、铁酸钙等副产物,故合成条件对水合碳铁酸钙含量及脱硅效果有重要影响。为了探讨反应机理并优化合成参数,研究采用傅里叶变换红外光谱(FTIR)、电感耦合等离子发射光谱(ICP-AES)分析对合成过程产物进行了物相分析和脱硅实验。FTIR和脱硅过程元素分析表明水合碳铁酸钙在水溶液中为介稳物质,反应温度和反应时间对水合碳铁酸钙的合成具有重要影响,随时间和温度增加水合碳铁酸钙含量先增加后减少;单因素条件下最优的合成条件为,反应温度30℃,反应时间16 h,反应液固比20,搅拌强度500 r.min-1;对最优条件下合成水合碳铁酸钙的物相结构进行了研究,表明水合碳铁酸钙为斜方六面体晶体结构,其中存在结晶水、羟基、Fe—O特征峰。For removing silica from high concentration medium after digestion of the diasporie bauxite by sub-molten salt, the research used calcium hydroferroearbonate with the new desilication reagent. In the reaction, calcium carbonate, calcium hydroxide and calcium ferrite were by-product, therefore the reaction factors showed significant influence on the synthesis and disilieating efficiency. To explore the synthesis mechanism and optimize the reaction factors, the composition of the intermediate obtained from the synthesis reaction was investigated through the combination of FTIR, ICP-AES and desilieation reaction. The FTIR and desilieation reaction results revealed that caleiurn hydroferroearbonate is metastable compound in solution, and the reaction temperature and reaction time have significant influence on the systhesis. With the temperature and reaction time increasing, the content of calcium hydroferrocarbonate in the composition first increased and then reduced. The optimal factors were： temperature of 30 ℃, reaction time of 16 hours, the liquid to solid mass ratio of 20 and rpm of 500 r · min^-1. The crystal structure of calcium hydroferrocarbonate was investigated, and was found to be rhombohedral, including H2 O bond, -OH bond and Fe-O bond.

关 键 词：光谱学研究 脱硅剂合成 水合碳铁酸钙 物相分析 

分 类 号：O644.1[理学—物理化学]