药剂协同强化不连沟煤泥浮选试验研究

Experimental study on synergistic effect of collectors to strengthen the flotation of Buliangou coal slime

不连沟煤泥为长焰煤,其灰分高、微细粒含量及高密度物含量均高,浮选分离难度大。为实现不连沟煤泥的有效分选,分别以十二烷(非极性药剂)、苯甲酸戊酯(酯类极性药剂)和双十二烷基二甲基溴化铵(DDAB,阳离子型Gemini表面活性剂)为捕收剂,探究了不同种类的药剂及复配药剂对不连沟煤泥的分选效果。通过接触角、FT-IR红外光谱、Zeta电位测定和量子化学计算分析了药剂作用机理。试验结果表明,单独以上述药剂为捕收剂时,十二烷捕收效果差,高药剂用量下苯甲酸戊酯展现出较好的捕收能力和选择性,DDAB捕收能力较好,但选择性差。以DDAB为基础分别与十二烷和苯甲酸戊酯复配使用,发现复配药剂作用下不连沟煤泥浮选效果得到有效改善,其中,DDAB与苯甲酸戊酯复配时,添加2%的DDAB获得的精煤可燃体回收率达到83.63%,有效改善了不连沟煤泥的浮选效果。通过药剂作用机理发现,DDAB首先通过静电作用吸附在煤泥表面,在增强煤泥表面疏水性的同时对煤泥表面亲水位点起到掩蔽作用,强化了后续药剂在煤表面的吸附能力,即对亲水性煤泥表面起到活化作用。

Buliangou coal slime is a long-flame coal,and its ash content,fine particle content and highdensity content are high,and it is extremely difficult to separate by flotation.In order to achieve the effective separation of Buliangou coal slime,dodecane(non-polar agent),amyl benzoate(ester polar agent),and didodecyldimethylammonium bromide(DDAB,cationic Gemini surfactant)are used as collectors to investigate the selective effect of each reagent on Buliangou coal slime,and then the mechanism of action of the agent is analyzed by contact angle,FT-IR infrared spectroscopy,Zeta potential determination and quantum chemical calculation.The results show that when the above agents are used as collectors alone,the dodecane capture effect is poor,and amyl benzoate shows better capture and selectivity under high drug dosage,and DDAB has better capture,but the selectivity is poor.Based on DDAB,it is found that the flotation effect of Buliangou coal slime is effectively improved under the action of compound agent,and when DDAB is compounded with amyl benzoate,the recovery rate of refined coal combustible gas obtained by adding 2%DDAB reaches 83.63%,which effectively improved the flotation effect of Buliangou coal slime.Through the mechanism of action of the collectors,it is found that DDAB is first adsorbed on the surface of the slime through electrostatic action,which not only enhances the hydrophobicity of the surface of the slime,but also masks the hydrophilic sites on the surface of the slime,and strengthens the adsorption capacity of the follow-up agent on the coal surface,that is,it plays an activation role on the surface of the hydrophilic slime.