摘要
针对煤泥浮选过程中蒙脱石等黏土矿物难以与煤分离的难题,采用溶液化学计算、Zeta电位测试和吸附量测定等方法,结合煤和蒙脱石浮选分离实验结果,研究了Na_(2)SiO_(3)强化煤和蒙脱石浮选分离的作用机理。结果表明:采用Na_(2)SiO_(3)作抑制剂进行人工混合煤泥浮选实验,矿浆pH<6时,Na_(2)SiO_(3)水解产物以Si(OH)_(4)为主,此时对蒙脱石的选择性抑制效果更强,精煤灰分显著降低、精煤产率变化不大;矿浆pH>6时,Na_(2)SiO_(3)水解产物以SiO(OH)^(-)_(3)和SiO_(2)(OH)_(2)^(2-)为主,此时对煤和蒙脱石的抑制选择性变差,精煤灰分降低的同时、精煤产率也有所降低。同时,矿浆中添加抑制剂Na_(2)SiO_(3)后,煤和蒙脱石表面电位均发生负移且负电位均增大,导致煤和蒙脱石的相互分散效果增强;随着Na_(2)SiO_(3)初始浓度的增加,煤和蒙脱石表面Na_(2)SiO_(3)吸附量均逐渐增大,且蒙脱石对Na_(2)SiO_(3)的吸附量始终大大高于煤对Na_(2)SiO_(3)的吸附量。采用Na_(2)SiO_(3)作抑制剂用于实际煤泥浮选生产可显著改善浮选效果,精煤灰分可由16.22%降低为14.35%,且浮选精煤产率变化不大。
In view of the difficulty in the separation of clay minerals such as montmorillonite from coal in flotation,the mechanism of enhanced flotation separation of coal and montmorillonite using Na_(2)SiO_(3)was studied through flotation test by means of solution chemical calculation,Zeta potential test and adsorption capacity measurement.The results show that,using Na_(2)SiO_(3)as inhibitor for artificial slime flotation experiment,when the flotation pulp pH<6,the hydrolysate of Na_(2)SiO_(3)is mainly Si(OH)_(4) which have stronger selective inhibitory effects on montmorillonite than coal.Consequently,the clean coal ash content decreases significantly,and the clean coal yield changes little.When the pH>6 in the pulp,the hydrolysate of Na_(2)SiO_(3)is mainly SiO(OH);and SiO_(2)(OH)_(2)^(2-) which have poorer selective inhibitory effects on montmorillonite than coal.Consequently,the clean coal ash content and yield decrease.Besides,when the inhibitor Na_(2)SiO_(3)was added to the pulp,the surface potential of coal and montmorillonite both shifted negatively and increased,leading to the enhancement of the mutual dispersion effect of coal and montmorillonite.With the increase of the initial concentration of Na,SiOs,the adsorption capacity of Na_(2)SiO_(3)on the surface of coal and montmorllonite increases gradually,and the adsorption capacity of montmorillonite on Na_(2)SiO_(3)is always much higher than that of coal.Using Na_(2)SiO_(3)as inhibitor for flotation of actual production slime can significantly improve flotation effect.Clean coal ash content reduces from 16.22%to 14.35%,and the clean coal yield has little change.
作者
李大虎
汪录
徐东方
王建忠
荣令坤
曹钊
LI Dahu;WANG Lu;XU Dongfang;WANG Jianzhong;RONG Lingkun;CAO Zhao(School of Mining and Coal,Inner Mongolia University of Science and Technology,Baotou 014010,China;School of Chemical and Environmental Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China)
出处
《煤炭工程》
北大核心
2023年第5期160-165,共6页
Coal Engineering
基金
国家自然科学基金资助项目(51904160)
内蒙古科技大学创新基金项目(2017QDL-B13)。
关键词
水玻璃
煤泥浮选
黏土矿物
抑制剂
sodium silicate
slime flotation
montmorillonite
inhibitor
