School of Chemical and Environmental Engineering,China University of Mining and Technology(Beijing),Beijing　 100083,China

为探讨超细粉碎对煤表面性质及絮团和超净煤分选的影响,选取淮南气煤(HN)和太西无烟煤(TX)2种不同变质程度的煤样,利用傅里叶红外光谱仪(FTIR)、ζ电位仪、比表面分析仪、微量热仪分析了不同超细粉碎时间后煤颗粒表面官能团、电位以及润湿性的变化,分别研究了粒度、表面电位和润湿性对絮团形成的影响,结合超净煤的分选结果,综合探讨了超细粉碎、表面性质变化、絮团形成以及超净煤分选的关系。结果表明:超细粉碎改变了煤粒表面的亲水基和疏水基的比例;随着粒度的减小,太西煤的电动电位绝对值先减小后增大,在粒度8.30μm时电负性最弱,润湿热出现小的峰值,搅拌过程中形成的大尺度絮团较多,在乳化柴油用量67.62 kg/t时,分选出的超净煤灰分0.68%,产率高达97.26%;而淮南煤随着粒度的减小,电负性逐渐增强,润湿热单调递减,润湿性逐渐减弱,在相同搅拌强度下,细颗粒形成的大尺度絮团减少,分选出的超净煤产率降低;分散剂的加入有效地降低了淮南气煤分选出超净煤的灰分,粒度越小,灰分减小愈明显。

In order to understand the effect of ultra-fine grinding on the coal surface properties and super clean coal separation,Huainan gas coal (HN) and Taixi anthracite (TX) were investigated in this study. Fourier transform infra- red spectroscopy (FTIR),ζ potential meter,microcalorimeter and specific surface analyzer were used to analyze the variation of surface functional groups,electric potential and wettability after ultra-fine grinding. The effects of particle size,surface potential and wettability on the formation of floccules were studied. Also,combined with the separation re- sults of ultra-clean coal,the relationship between ultra-fine grinding,surface property change,floccules formation and the separation of ultra-clean coal was discussed synthetically. The results show that ultra-fine crushing changes the pro- portion of hydrophilic group and hydrophobic group on coal surface. With the decrease of particle size,the electric po- tential absolute value of TX coal decreases firstly,then increases. In the particle size of 8. 30 μm,the negative power is the weakest,the wetting heat is larger,more large scale floccules are formed in the process of mixing. When the usage of emulsified diesel oil is 67. 62 kg / t,the ash of ultra clean coal ash separated is 0. 68% and the yield is 97． 26% . Whereas,with the decrease of particle size,the electric potential absolute value of HN coal increases gradually,and the heat of wetting is monotonously decreasing. Under the same stirring intensity,the amount of floccules formed by fine particles is decreased,and the yield of ultra clean coal separated is reduced. The addition of dispersant effectively re- duces the ash of clean coal,and the difference of ash content is gradually increasing with the decrease of particle size.

国家自然科学基金资助项目(51474221)；

Wang Jie,Fu Xiaoheng,Zhao Jing,et al. Effect of ultra-fine grinding on coal surface properties and ultra-clean coal separation[J]. Journal of China Coal Society,2016,41(6):1524-1532.