胜利褐煤的改性油泡浮选机理

针对胜利褐煤亲水性强、可浮性差的特点,从降低表面亲水性入手,采用2-乙基己醇、2-辛酮和苯乙酸甲酯对普通柴油油泡进行了改性,通过诱导时间对改性油泡的黏附性能进行了表征,借助傅里叶变换红外光谱技术分析了表面活性剂的吸附位点,并通过计算基团电负性进行了药剂吸附方式的分析,丰富了低阶煤油泡浮选的基础理论。实验结果表明:2-乙基己醇和2-辛酮改性的油泡对褐煤的诱导时间可以降低至40 ms左右,在相同的药剂消耗下,改性油泡比普通油泡的可燃体回收率最高增幅超过60%。FT-IR的分析表明表面活性剂能够抑制褐煤表面—OH的亲水作用,从而提高其可浮性。结合各项测试和基团电负性计算的结果进行分析,可以认为醇—OH能够与煤表面O发生氢键作用,能有效降低亲水性;2-辛酮在高浓度配比下有良好的效果;苯乙酸甲酯中的苯环容易吸附到褐煤的疏水表面,会对药剂中含氧基团的作用效果起到负面影响。

Mechanism of modified-oily-bubble flotation of Shengli lignite

Characterized by high hydrophilicity,Shengli lignite is difficult to obtain satisfactory flotation results.In order to inhibit hydrophilic effect of oxygen-containing groups,oily-bubble modified respectively by 2-ethyl hexanol,octanone and methyl phenyl acetate was tested in flotation.Induction time was used to evaluate the adhesion capacity of modified-oily-bubble and the adsorption sites of surfactants was analyzed by FT-IR technique.Combining test results and group electronegativity,a comprehensive analysis of adsorption mechanism was carried out,which enriched the basic theory of oily-bubble flotation.The results showed that the induction time of oily-bubble modified by 2-ethyl hexanol and octanone can be reduced to about 40 ms,meanwhile,combustible matter recovery was increased over 60%.FT-IR analysis indicates that surfactants used above could enhance the floatability of Shengli lignite mainly by inhibit hydrophilic effect of -OH.Compared the group electronegativity and test results,it can be concluded that alcoholic hydroxyl group interact with the oxygen-containing groups of lignite surface by hydrogen bond,which is the most effective way.Ketonic oxygen of octanone associated with coal surface groups by covalent bond and it works well in high surfactant concentration.The benzene ring of methyl phenyl acetate was more readily to adsorb onto hydrophobic sites of coal surface,thus prevent valid interaction of agent oxygen-containing groups.