界面润湿性调控对氧化煤浮选的促进作用

Promoting Effects of Wettability Modification on Oxidized Coal Flotation

煤炭的氧化使其表面疏水性减弱,可浮性显著降低。表面活性剂通过其亲水基团作用于煤表面的极性含氧官能团能够改变其表面润湿性。本文用十六烷基三甲基溴化铵(CTAB)对氧化煤进行表面润湿性调控,通过红外光谱和润湿热测定分析了CTAB在煤表面的吸附特性及煤表面的润湿性变化,结果表明,氧化煤吸附CTAB后,煤表面疏水性增强,可浮性随CTAB吸附量增大而提高;CTAB吸附于煤的同时也吸附于矿物质,矿物质表面由亲水同样转为疏水,精煤灰分大幅提升,分别采用浮选作业前水热预处理和添加六偏磷酸钠作为灰抑制剂,浮选精煤降灰效果显著。

The decreasing of surface hydrophobicity duo to coal oxidation leads to flotability significantly reduced. The impact of surfactant hydrophilie hydrophilic end on lignite surface polar oxygen-containing groups groups have profound effects on coal surface wettability changes, which could bring coal surface wettability alteration from hydrophilicity to hydrophobicity. Surfactant cetyhrimethyl amonium bromide （CTAB）was chosen and its influence on the surface wettability of lignite were investigated. The adsorption characteristics of CTAB adsorbed on oxidized coal sur- face and the changes of wettability of were analyzed using FTIR and wettability heat measurement. The obtained re- suits show that the oxidized coal adsorbed CTAB leads to hydrophobicity increasing and flotability was effectively promoted. Moreover, flotability increased with CTAB adsorbing capacity. It was also observed that the adsorption of surfactant on coal could result in mineral matter wettability alteration from hydrophobicity to hydrophilieity, which bought clean coal ash increasing drastically. It was proved that the hydrothermal pretreatment before flotation opera- tion and using inhibitor respectively lead to clean coal ash decreasing efficiently.