硫酸氢铵与石棉尾矿混合焙烧浸取MgO过程分析  

Research on MgO extracted in chrysotile asbestos tailings with ammonium bisulfate via mix-roasting

作　　者：孙红娟[1] 宋鹏程[1,2] 彭同江[1,3] 谭道永[1] 张海阳[1] 

机构地区：[1]西南科技大学固体废物处理与资源化教育部重点实验室,四川绵阳621010 [2]绵阳市环境监测中心站,四川绵阳621010 [3]西南科技大学分析测试中心,四川绵阳621010

出　　处：《岩石矿物学杂志》2015年第6期853-859,共7页Acta Petrologica et Mineralogica

基　　金：四川省创新团队项目(14TD0012);固体废物处理与资源化教育部重点实验平台基金(14tdgk02)

摘　　要：主要化学成分是SiO2和MgO的石棉尾矿与作为化学助剂的硫酸氢铵混合焙烧后可提取MgO并分离出活性SiO2残渣。本文研究了这一焙烧过程中主要金属氧化物的浸取率(以MgO表征)、焙烧产物水浸残渣剩余量及其与物相组成之间的相互关系,获得了优化的混合焙烧工艺参数,并结合焙烧水浸产物的物相变化,分析了焙烧过程中矿物和生成物的变化。结果表明,在NH4HSO4/MgO(摩尔比)为4、焙烧温度为500℃、焙烧时间为2 h、尾矿粒度为120目的条件下,石棉尾矿中的矿物分解最为彻底,MgO提取率最高;焙烧过程中,水镁石、方解石和富铬斜绿泥石反应活性高,蛇纹石次之,滑石最差;石棉尾矿中的金属氧化物与硫酸氢铵反应形成可溶硫酸盐,而硅氧四面体骨架转变成无定形活性SiO2残骸。研究结果对石棉尾矿的资源化利用和环境保护具有重要意义。Based on the fact that the compositions of chrysotile asbestos railings are mainly SiO2 and MgO）, me authors efficiently extracted MgO from chrysotile asbestos tailings with ammonium bisulfate via mix-roasting, and investigated the interrelationships between MgO extracting rate, washing mix-roasting residue and phase so as to get the optimal mix-roasting parameters. According to the physical phase variationd the washing mix- roasting residues, the authors analyzed the change of minerals and products in the mix-roasting process. The re- sult shows that the optimum conditions for the elimination of mental oxides in mix-roasting were 4 for NH4HSO4/MgO molar ratio, 500℃ for the roasting temperature, 2 h for the roasting time, and 120 mesh for the particle size. Brucite, calcite and kotschubeite were most reactive in the mix-roasting process, followed by serpentite and then by talc. The mental oxides in chrysotile asbestos railings were changed into soluble sulfate af- ter being reacted with ammonium bisulfate. Meanwhile, Si-O tetrahedral sheet was retained and modified, and finally active silica residue was preserved. The results obtained by the authors have an important significance for the efficient utilization of chrysotile asbestos tailings.

关 键 词：石棉尾矿 硫酸氢铵 MGO 活性SiO2 

分 类 号：X753[环境科学与工程—环境工程] P579[天文地球—矿物学]