油泡-低阶煤颗粒间的黏附特性

在浮选矿浆中矿物颗粒能够有效地黏附在气泡上完成矿化过程是浮选技术的关键。用油泡代替气泡,研究难浮低阶煤颗粒与油泡间的相互作用及其黏附特性对于弄清其矿化机制至关重要。从矿物表面电性入手,探究了溶液p H值和表面活性剂对煤样与油泡间作用力的影响,运用DLVO理论计算了相互作用力的大小,并通过诱导时间这一重要参数评价了黏附效率。实验结果表明,DLT煤样和油泡的等电点分别出现在p H值2~3和p H值3~5之间;当p H=3时溶液中煤样与油泡之间的相互作用不存在能垒;p H3时开始出现能垒,并随p H值的增大而增大。2-乙基己醇和双十二烷基二甲基溴化铵的加入能够有效地减小煤样与油泡之间的能垒并降低诱导时间,最大降幅分别为74.35%和86.45%。

Attachment characteristics between oily bubbles and low rank coal particles

Bubble-mineral particles attachment and mineralization process are critical to flotation technology which can realize the effective separation of coal and gangue.It is indispensable for understanding the mechanism of mineralization process in flotation to investigate the interaction between low rank coal particles and reactive oily bubbles by electrochemistry studies and induction time measurements.In this paper,the influence of pH of solution and surfactants on the interaction between low rank coal particles and reactive oily bubbles which can be estimated by the DLVO theory was investigated.And the attachment efficiency was evaluated by the induction time measurements.The results showed that the isoelectric point(IEP) of coal particles and diesel oily bubbles was observed over the range of pH 2-3 and pH 3-5,respectively.No interaction energy barrier between coal particles and diesel oily bubbles was observed in the tested solution of pH 3,while the interaction energy barrier appeared and gradually increased with the increase of pH value when it exceeded 3.It indicated that the interaction energy barrier and induction time between coal particles and diesel oily bubbles modified by surfactants 2-ethylhexanol and didodecyldimethylammonium bromide were lower than diesel oily bubbles,with the maximum decrease of 74.35% and 86.45% respectively.