超重力反应结晶法合成微细针状碳酸钙研究  

Synthesis of Ultra-fine Needle-like Calcium Carbonate Particles by High-Gravity Reactive Precipitation

作　　者：朱万诚[1] 王玉红[1] 陈建峰[1] 

机构地区：[1]教育部超重力工程研究中心,北京化工大学北京100029

出　　处：《高校化学工程学报》2002年第5期560-564,共5页Journal of Chemical Engineering of Chinese Universities

基　　金：北京市新星计划资助项目(9558103500);新加坡纳米材料科技公司资助项目。

摘　　要：采用超重力反应结晶法,在旋转填充床(RPB)反应器中,以Ca(OH)2-CO2为反应物系,MgCl2作为晶形控制剂,合成出了短轴为80～200nm、长径比为12～20且短轴及长径比分布较窄的微细针状碳酸钙,并对Ca(OH)2初始浓度、气液比、旋转床转速、反应温度以及MgCl2浓度等因素的影响进行了深入的研究.结果表明,当Ca(OH)2初始浓度为6.0%～7.5%、气液比为0.08～0.2、旋转床转速为900～1200r.min-1、反应温度为55～75℃、MgCl2浓度为2.0%～6.0%时能稳定地生成微细针状文石型碳酸钙.合成等量的针状碳酸钙,超重力反应结晶法所需碳化时间约为文献值的1/18.Needle-like calcium carbonate is well noticed for its higher reinforcement than granular calcium carbonate particles, a novel technology to synthesize ultra-fine needle-like calcium carbonate was studied in this paper. Ultra-fine needle-like calcium carbonate particles were successfully synthesized by high-gravity reactive precipitation in the rotating packed bed (RPB) reactor. The particles have the mean shaft diameter of 80~200nm and the average aspect ratio of 12~20 with the narrow distribution of the short shaft and the aspect ratio. In the experiments, Ca(OH)2 milk and CO2 were used as reactants and MgCl2 was used as the shape-control additive. The effects of initial concentration of Ca(OH )2 milk, volumetric flow rate ratio of gas to liquid, rotating speed of RPB, reaction temperature and concentration of the additive on the preparation process were investigated. The results showed that ultra-fine needle-like CaCO3 can be synthesized and well-controlled under the following conditions: the initial concentration of Ca(OH)2 6.0%~7.5%, volumetric flow rate ratio of gas to liquid 0.08~0.2, rotating speed of RPB 900~1200r穖in-1, reaction temperature 55~75C and concentration of MgCl2 2.0%~6.0%. The needed carbonation time that the same amount of needle-like CaCO3 are synthesized by high-gravity precipitation is 1/18 of that has been reported by using other technology.

关 键 词：微细针状碳酸钙 超重力反应结晶法 旋转填充床 合成 

分 类 号：TQ132.32[化学工程—无机化工]