热处理温度对菱镁尾矿合成Mg_(2)SiO_(4)-MgAl_(2)O_(4)-MgO复相砂的影响  

Influenceof heat treatment temperature on synthesis of Mg_(2)SiO_(4)-MgAl_(2)O_(4)-MgO complex sand from magnesite tailings

作　　者：林浩鑫 田琳 刘晓妍 解重重 宋博 李国华 LIN Haoxin;TIAN Lin;LIU Xiaoyan;XIE Chongchong;SONG Bo;LI Guohua(School of Materials and Metallurgy,University of Science and Technology Liaoning,Anshan 114051,China)

机构地区：[1]辽宁科技大学材料与冶金学院,辽宁鞍山114051

出　　处：《化工环保》2024年第3期427-431,共5页Environmental Protection of Chemical Industry

基　　金：国家自然科学基金项目(U20A20239)。

摘　　要：向菱镁尾矿中添加12%(w)Al_(2)O_(3),采用固相法合成Mg_(2)SiO_(4)-MgAl_(2)O_(4)-MgO复相砂。研究了热处理温度对合成复相砂的矿物相组成及结构的影响。结果表明:热处理温度1400~1600℃均可合成Mg_(2)SiO_(4)-MgAl_(2)O_(4)-MgO复相砂,热处理温度升高可促进复相砂中镁铝尖晶石含量的增加,及镁橄榄石与镁铝尖晶石晶体发育程度的完善;1600℃下所合成复相砂具有完善的晶体结构与最高的致密度;1400℃热处理后的试样疏松,存在大量气孔,镁橄榄石分布在孔壁处,镁铝尖晶石分布在孔隙之中。随着热处理温度升高,镁橄榄石和镁铝尖晶石晶粒迅速长大,同时菱镁尾矿中的Fe^(3+)、Ca^(2+)杂质会与镁铝尖晶石和镁橄榄石形成固溶体,热处理温度的提升和固溶体的形成共同促进试样烧结致密化,使体积密度提高,显气孔率降低。Mg_(2)SiO_(4)-MgAl_(2)O_(4)-MgO complex sand was synthesized byadding 12%(w)Al_(2)O_(3)to magnesite tailingsby means of the solid phase method.The influenceof heat treatment temperature on the mineral phase composition and microstructure of the synthesized complex sand was investigated.The results show thatMg_(2)SiO_(4)-MgAl_(2)O_(4)-MgO complex sand can be synthesized at a heat treatment temperature of 1400-1600℃,and the increase inheat treatment temperature will enhance thecontent of magnesium-aluminum spinel in complex sand and improve the development degree of magnesium-aluminum spinel and forsterite crystals.Complex sand synthesized at 1600℃has a well-developed crystal structure,with the highest density.After heat treatment at 1400℃,the sample is loose and has a large number of pores.Forsterite is distributed in the pore wall,and magnesium-aluminum spinel is distributed in the pores.With the increase inheat treatment temperature,the forsterite and magnesium-aluminum spinel crystals rapidly grow.At the same time,the Fe^(3+)and Ca^(2+)impurities in the magnesite tailings will form solid solutions with the forsterite and magnesium-aluminum spinel.The increase in heat treatment temperature and the formation of solid solutions promote the sintering densification of the sample,increase the bulk density,and decrease the apparent porosity.

关 键 词：菱镁尾矿 热处理温度 复相砂 镁橄榄石 镁铝尖晶石 显微结构 

分 类 号：X781.5[环境科学与工程—环境工程]