超声条件下离子与表面活性剂对低阶煤泥浮选的影响

Effects of ions and surfactant on low-rank coal slime flotation under ultrasonic conditions

低阶煤中有机质与矿物质润湿性的差异决定了浮选作业的效果,为提高低阶煤的浮选效率,采用先后吸附钙离子与表面活性剂(C12EO15),再用超声波脱附C12EO15的方法处理低阶煤泥。结果表明,钙离子会促进C12EO15吸附在有机质表面,吸附量由7.14 mg/g提升至7.39 mg/g。当脱附处理60 s后,C12EO15会从有机质表面脱附下来,但会进一步吸附在矿物质表面。脱附处理后有机质表面疏水官能团与亲水官能团的含量同时增加,润湿热值由31.79 J/g提升至32.93 J/g。随脱附时间的增加,浮选精煤的产率与精煤灰分也随之上升,脱附处理30 s时,可以得到较优浮选效果,精煤产率为72.01%,精煤灰分为30.85%。

The quality of flotation depends on the different wettability between organic and mineral matter.A method was adopted in order to promote the performance of low-rank coal flotation,in which the low-rank coal slime first adsorbed calcium ions and then surfactant molecules(C12EO15)and reached adsorption equilibrium,and was finally treated by ultrasonic wave to desorb the surfactant.The results indicated that calcium ions could promote the adsorption of C12EO15 on the surface of organic matter,in which the adsorption capacity was increased from 7.14 mg/g to 7.39 mg/g.When the time of desorption treatment reached 60 s,C12EO15 molecules would desorb from the surface of organic matter but further adsorb on the surface of mineral matter.The amounts of hydrophilic and hydrophobic functional groups on the surface of organic matter both increased after desorption treatment,and the wetting heat was improved from 31.79 J/g to 32.93 J/g.As the time of desorption treatment increased,the yield and ash content of clean coal increased,respectively.When the time of desorption treatment was 30 s,the best flotation performance could be obtained,in which the yield of clean coal was 72.01%and the ash content of clean coal was 30.85%.