碱溶—碳分法生产氧化铝过程中的质量控制  

Quality Control of Alkali Dissolution-Carbonation Precipitation Process for Alumina Producing

作　　者：马科友[1] 王红伟[1] 张学英 董凯伟 马靖威 潘晓林 MA Ke-you;WANG Hong-wei;ZHANG Xue-ying;DONG Kai-wei;MA Jing-wei;PAN Xiao-lin(Metallurgical and Chemical Department,Jiyuan Vocational and Technical College,Jiyuan 459000,Henan,China;School of Metallurgy,Northeastern University,Shenyang 110819,China;College of Chemistry and Chemical Engineering,Guangxi University,Nanning 530004,China)

机构地区：[1]济源职业技术学院冶金化工系,河南济源459000 [2]东北大学冶金学院,沈阳110819 [3]广西大学化学化工学院,南宁530004

出　　处：《有色金属（冶炼部分）》2022年第2期40-47,共8页Nonferrous Metals（Extractive Metallurgy)

基　　金：国家自然科学基金资助项目(51104041,22078055)。

摘　　要：碱溶—碳分法生产氧化铝打破了拜耳法Na_(2)O-Al_(2)O_(3)-H_(2)O体系固有的相平衡,分解效率大幅度提高。研究了用NaOH溶液溶解铝土矿得到铝酸钠溶液,考察了铝酸钠溶液脱硅净化、碳酸氢钠分解及氢氧化铝焙烧对氧化铝产品质量的影响。结果表明,经两次石灰净化脱硅(净化温度98℃;一次净化时间1 h,石灰添加量15 g/L;二次净化时间1 h,石灰添加量10 g/L),二段分解(分解温度90℃,碳酸氢钠质量浓度90~100 g/L,缓慢持续加入,分解时间不大于16 h(其中一段8~10 h),第一段分解率控制在85%左右),适宜条件下,所得氢氧化铝质量达到一级品或接近一级品,在1200~1250℃煅烧后所得氧化铝产品质量可达二级品要求。Alkali dissolution-carbonation precipitation process for alumina producing is a new process,which equilibrium of Na_(2)O-Al_(2)O_(3)-H_(2)O system in Bayer process is broken and production efficiency is enhanced significantly.Applying sodium aluminate solution leached by NaOH solution as raw materials,effects of desilication from sodium aluminate solution,decomposition of sodium aluminate with sodium bicarbonate,carbonization with sodium bicarbonate,and aluminum hydroxide roasting process on quality of products were investigated.The results show that quality of first-stage aluminum hydroxide meets or close to the standard of the first grade under the suitable conditions of twice purification desilication with lime(desilication temperature of about 98℃,first stage purification time of 1 h with lime addition of 15 g/L,and second stage purification time of 1 h with lime addition of 10 g/L),and two-stage decomposition of sodium aluminate solution(decomposition temperature of 90℃,concentration of sodium bicarbonate solution of 90~100 g/L,decomposition time of first stage of 8—10 h,total decomposition time of 16 h below,and decomposition ratio first stage of about 85%).The quality of alumina products of aluminum hydroxide calcined at 1200-1250℃can reach the requirements of second grade products.

关 键 词：碳酸化分解 脱硅 焙烧 氢氧化铝 氧化铝 质量控制 

分 类 号：TF821[冶金工程—有色金属冶金]