Adhesion forces for water/oil droplet and bubble on coking coal surfaces with different roughness  

作　　者：Chunyun Zhu Guosheng Li Yaowen Xing Xiahui Gui 

机构地区：[1]Chinese National Engineering Research Center of Coal Preparation and Purification,China University of Mining and Technology,Xuzhou 221116,China [2]School of Chemical Engineering and Technology,China University of Mining and Technology,Xuzhou 221116,China [3]School of Chemical Engineering and Technology,Zhengzhou University,Zhengzhou 450052,China

出　　处：《International Journal of Mining Science and Technology》2021年第4期681-687,共7页矿业科学技术学报（英文版）

基　　金：This work was supported by the Jiangsu Natural Science Fund-Youth Fund(BK20190639);National Nature Science Foundation of China(Nos.21978318,51904300,and 51922106);National Key R&D Program of China(2020YFC1908803).

摘　　要：Surface roughness plays a significant role in floatability of coal.In the present paper,coking coal surface was polished by three different sandpapers and the surface properties were characterized by contact angle and roughness measurements.The effect of surface roughness on floatability was investigated by adhesion force measurement system for measuring interaction forces between droplets/bubbles and coking coal surfaces with different roughness.The results showed that the contact angle decreased with increasing roughness yet the adhesion force between the water droplet and coal surface increased owing to the increased contact line and the appearance of line pinning.Maximum adhesion forces between water and surfaces were 111.70,125.48,and 136.42μN when the roughness was 0.23,0.98,and 2.79 μm,respectively.In contrast,under a liquid environment,the adhesion forces between air bubble/oil droplet and coal surfaces were decreased with increasing roughness because of the restriction by water.Maximum adhesion forces of increasing roughness were 97.14,42.76,and 17.86 μN measured at interfaces between air bubble and coal surfaces and 169.48,145.84,and 121.02 lN between oil droplet and surfaces,respectively.Decreasing roughness could be beneficial to the spreading of oil droplets and the adhesion of bubbles which is conducive to flotation separation.

关 键 词：Adhesion force Water/oil droplet Air bubble ROUGHNESS FLOATABILITY 

分 类 号：TD94[矿业工程—选矿] TD923