氯化铁溶液赤泥控碱作用及效果  

Function and effect of ferric chloride solution in alkaline regulation of red mud

作　　者：岳远隋 成官文[1] 徐敏 徐晓宇 张振林 农国武[2] YUE Yuansui;CHENG Guanwen;XU Min;XU Xiaoyu;ZHANG Zhenin;NONG Guowu(College of Environmental Science and Engineering,Guilin University of Technology,Guilin 541006,China;Guangxi Branch of Aluminum Corporation of China Limited,Baise 531499,China)

机构地区：[1]桂林理工大学环境科学与工程学院,广西桂林541006 [2]中国铝业股份有限公司广西分公司,广西百色531499

出　　处：《无机盐工业》2023年第11期121-129,共9页Inorganic Chemicals Industry

基　　金：中国铝业股份有限公司科技攻关项目(gxzz201903);广西重点研发计划项目(桂科AB20297039);矿泥土壤化处置示范及赤泥矿泥土壤化处置技术工程应用项目(gxzz202210)。

摘　　要：针对赤泥碱性调控过程中存在的碱性强、控碱成本高等难题,以赤泥回收精铁矿生产的FeCl_(3)溶液为控碱药剂,对赤泥进行控碱及陈化处置。结果表明:FeCl_(3)溶液会使赤泥中可溶性钠碱含量显著降低,水化石榴石、方钠石等结合碱出现不同程度的溶解、转化,置换出的Na^(+)、Ca^(2+)等离子以石盐、Ca Cl2等矿相的形式在控碱赤泥表层结晶析出;Fe^(3+)的吸附、聚集作用使得控碱赤泥表层孔径降低、比表面积显著增加、表面更为致密,致使药剂在赤泥控碱前期下渗缓慢,控碱效果受限;FeCl_(3)溶液可以通过中和、沉淀作用显著降低赤泥碱分,控碱反应至30 d时整体控碱赤泥pH稳定在8.50左右,且随着陈化时间的延长其碱性并无显著反弹,反应、陈化历程可依次分为快速反应、迁移转化、溶解反弹、平衡构建4个阶段。To address the problems of strong alkalinity and high cost of controlling alkalinity in the process of alkaline regu-lation of red mud,it was proposed that FeCl_(3) solution produced by recovering refined iron powder from red mud worked as an alkali control agent to control alkalinity and conduct aging of red mud.The results showed that FeCl_(3) solution could sig-nificantly reduce the soluble alkali,such as NaOH,Na_(2)CO_(3),NaHCO_(3),NaAl(OH)_(4)in red mud,and the combined alkali,like hy-drated garnet and sodalite,had different degrees of dissolution and transformation.The replaced Na+and Ca^(2+)ions crystal-lized in the surface layer of alkali-controlled mud as halite,CaCl_(2) and other mineral phases.The adsorption and aggregation of Fe^(3+)made the surface pore diameter of alkali-controlled mud decrease,and the specific surface area was increased signifi-cantly,and the surface became compact accordingly,which made the agent penetrate slowly in the early stage of alkali con-trol of red mud and limited alkali control performance.In addition,FeCl_(3) solution could significantly reduce the alkali con-tent of red mud through neutralization and precipitation.After 30 days of reaction and aging,the pH of the red mud was sta-bilized at about 8.50,and there was no significant rebound in late aging.The reaction and aging process could be divided into four stages,such as rapid reaction,migration and transformation,dissolution and rebound,and balanced construction.

关 键 词：赤泥 FeCl_(3)溶液 碱性调控 矿相组分 控碱机制 

分 类 号：X753[环境科学与工程—环境工程]