School of Chemical Engineering and Technology,China University of Mining and Technology,Xuzhou ,China

针对常规浮选药剂(如柴油、煤油等)难以实现难浮煤泥的高效浮选回收问题,以难浮炼焦煤泥为研究对象,基于炭黑颗粒的超疏水特性,将炭黑颗粒与正十二烷按1 g∶150 m L的比例混合配制成炭黑-正十二烷新型捕收剂,对比分析正十二烷和新型捕收剂对炼焦煤泥的浮选效果。采用X射线光电子能谱(XPS)和接触角测定仪对炭黑颗粒的表面疏水性进行测定,采用扫描电镜和能谱仪(SEM/EDS)分别对2种捕收剂作用前后煤表面颗粒形貌和元素进行表征。结果表明:炭黑颗粒主要含碳,表面官能团以C—C和CC为主,接触角达136°,极其疏水;新型捕收剂作用后的煤表面吸附有较多的纳微颗粒,且其表面碳元素含量显著高于正十二烷作用后的煤表面,表明炭黑颗粒可吸附于煤表面。炭黑-正十二烷的混合物作为捕收剂,不但增加了煤表面的疏水性,且炭黑颗粒吸附于煤表面可以增加煤表面的固体凸起点,从而在气泡-煤粒粘附过程中加速水化膜的破裂,促进煤粒-气泡粘附效率,提高难浮煤的浮选回收效果。

The common oily collectors,such as diesel,kerosene and others are not effective for difficult-to-float coal flotation.In this paper,the difficult-to-float coking coal was used as the coal sample,based on the super-hydrophobicity characteristics of soot particles,and the soot particles and n-dodecane were mixed in 1 g:150 mL ratio to form a novel soot- dodecane collector.The flotation results of coking coal using dodecane or novel collector were analyzed and compared.X-ray photoelectron spectroscopy (XPS) and contact angle measurements were used to indicate the surface hydrophobicity of soot.Scanning electron microscopy with energy dispersive spectrometer (SEM/EDS) was used to show the surface morphology and elements of the coal before and after the reaction with the two kinds of collectors.The results show that the soot particles mainly consisted of carbon,the surface functional groups are dominated by C—C and Cwidth=23,height=11,dpi=110C while the contact angle reaches 136°,and they are extremely hydrophobic.The coal surface after the new collector reactions adsorbed more nanoparticles and ultra-fine particles,and contained higher carbon content than that after dodecane reaction.It indicates that the soot particles can adsorb on the coal surface.The soot- dodecane mixture acts as a collector not only improving the surface hydrophobicity of coal but also increasing the surface solid convexity through the adsorption of soot particles on the coal surface,thereby speeds up the rupture of water film during bubble-coal adhesion,promotes the coal particle-bubble adhesion efficiency and improves the flotation recovery of difficult-to-float coal.

国家自然科学基金青年科学基金资助项目(51604272)；江苏省自然科学基金青年基金资助项目(BK20160260)；