An Maoyan, Liao Yinfei, Yang Zhe, Cao Yijun, Hao Xiaodong, Song Xingwei, Ren Hourui, Yang Aosheng, Chen Luojian
School of Transportation Engineering, Jiangsu Vocational Institute of Architectural Technology, Xuzhou 221116, Jiangsu, P.R. China.
Jiangsu Engineering Lab of Biomass Resources Comprehensive Utilization, Jiangsu Vocational Institute of Architectural Technology, Xuzhou 221116, Jiangsu, P.R. China.
ACS Omega. 2022 May 25;7(22):18315-18322. doi: 10.1021/acsomega.2c00453. eCollection 2022 Jun 7.
It has been generally proved that mixed collectors can enhance the flotation of low-rank coal (LRC). However, the inhibition effect of mixed collectors on the detachment between particles and bubbles is still unclear. In this paper, the energy feature of air bubble detachment from the LRC surface in the presence of dodecane (D), oleic acid (OA), and the mixture of dodecane and oleic acid (OA-D) was studied. The effect of collectors on the LRC surface property was analyzed using contact angle measurement, X-ray photoelectron spectroscopy, and wetting heat measurement. The force and displacement during the detachment process were measured synchronously using microforce balance. The results showed that the collector treatment increased the C-C/C-H content and decreased the content of oxygen-containing groups on the LRC surface. The synergistic effect between OA and D enabled the mixed collector to exhibit higher contact angle and wetting heat. Bubble detachment from the LRC surface can be divided into two stages: bubble stretching and bubble sliding, which corresponded to activation energy and detachment work, respectively. The activation energy and detachment work decreased in the same order of OA-D > OA > D, indicating that the mixed collector OA-D increased the energy of bubble detachment from the LRC surface and enhanced the adhesion strength. The theoretical detachment work was calculated, and the calculated results were in agreement with the measured results. This research provides a new perspective on the mechanism of LRC flotation being improved by mixed collectors.
一般已证明，混合捕收剂可提高低阶煤（LRC）的浮选效果。然而，混合捕收剂对颗粒与气泡分离的抑制作用仍不明确。本文研究了在十二烷（D）、油酸（OA）以及十二烷与油酸的混合物（OA-D）存在下，气泡从LRC表面脱离的能量特征。采用接触角测量、X射线光电子能谱和润湿热测量等方法分析了捕收剂对LRC表面性质的影响。使用微力天平同步测量了脱离过程中的力和位移。结果表明，捕收剂处理增加了LRC表面的C-C/C-H含量，降低了含氧基团的含量。OA和D之间的协同作用使混合捕收剂表现出更高的接触角和润湿热。气泡从LRC表面的脱离可分为两个阶段：气泡拉伸和气泡滑动，分别对应活化能和脱离功。活化能和脱离功按OA-D>OA>D的顺序降低，表明混合捕收剂OA-D增加了气泡从LRC表面脱离的能量，增强了附着强度。计算了理论脱离功，计算结果与测量结果一致。本研究为混合捕收剂改善LRC浮选机理提供了新的视角。
