低品位高硫铝土矿脱硅精矿溶出及微观结构演变  

Digestion performance and microstructure evolution of desilicated concentrate from low-grade high sulfur bauxite

作　　者：吴鸿飞 夏飞龙 李军旗[1,2] 陈朝轶 徐树涛[3] 张仕恒 WU Hongfei;XIA Feilong;LI Junqi;CHEN Chaoyi;XU Shutao;ZHANG Shiheng(School of Materials and Metallurgy,Guizhou University,Guiyang 550025,China;Guizhou Province Key Laboratory of Metallurgical Engineering and Process Energy Saving,Guiyang 550025,China;Guiyang Aluminum Magnesium Design&Research Institute Co.Ltd.,Guiyang 550025,China)

机构地区：[1]贵州大学材料与冶金学院,贵州贵阳550025 [2]贵州省冶金工程与过程节能重点实验室,贵州贵阳550025 [3]贵阳铝镁设计研究院有限公司,贵州贵阳550025

出　　处：《中南大学学报（自然科学版）》2019年第9期2074-2083,共10页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(U1812402,51774102,51574095,51564003);贵州省科技平台及人才团队建设计划项目([2015] 4005，黔教合KY字[2015]334号)~~

摘　　要：为有效开发与利用低品位高硫铝土矿,降低拜耳法流程中硫矿物的危害并提高氧化铝溶出率,采用高压溶出工艺考察苛碱质量浓度、时间、石灰添加量和温度对脱硅精矿溶出性能的影响。研究结果表明:最佳溶出条件为溶出条件为温度280℃,苛碱质量浓度245 g/L,时间70 min,石灰添加质量分数8%,在此条件下的相对溶出率为95.14%,比原矿和焙烧矿相对溶出率分别提高7.50%和9.77%,脱硅精矿溶出液中硫质量浓度为0.11 g/L,硫的实际溶出率为11.2%;脱硅精矿比表面积增大为31.25 m^2/g,孔容和孔径分别增至0.0784 cm^3/g和14.76 nm;氧化铝晶体[113]面在碱浸过程中晶粒粒径减小;脱硅精矿晶面间距减小,Al—O键长变大并存在0.185 4和1.971 0 nm 2种键长。To effectively develope and utilize the low grade high sulfur bauxite,and reduce the hazards of sulfur minerals in the Bayer process and improve the digestion properties of alumina,the effects of caustic alkali mass concentration,time,lime addition amount and temperature on the digestion performance of desilicated concentrate were systematically investigated after roasting desulfurization and alkali leaching desilication.The results show that the best digestion conditions are as follows:the digestion temperature is 280℃;the caustic mass concentration is 245 g/L;the digestion time is 70 min;the lime mass fraction is 8%.The relative digestion ratio is 95.14%,which is 7.50%higher than that of the raw ore and 9.77%higher than that of the calcined ore,respectively.The mass concentration of sulfur in the digestion solution of desilicated concentrate is 0.11 g/L,and the actual digestion ratio of sulfur is 11.2%.The specific surface area of desilicated concentrate increases to 31.25 m^2/g,pore volume and pore diameter increase to 0.078 43 cm^3/g and 14.76 nm,respectively.The reaction of[113]surface of alumina crystal during alkali leaching process leads to the decrease of grain size.The interplanar spacing of desilicated concentrate decreases and the length Al-O increases,with two bond lengths of 0.185 4 nm and 1.9710 nm,respectively.

关 键 词：高硫铝土矿 高压溶出 比表面积 晶体结构 

分 类 号：TF11[冶金工程—冶金物理化学]