机械能输入对超净煤分选中絮团生成的影响

研究了超净煤制备工艺中机械能输入对絮团生成的作用机理，利用扩展的DLVO理论计算微细煤粒间的作用势能并绘制势能曲线，说明机械能的输入是使微细煤粒间克服势能曲线能垒形成絮团的必要条件；对絮团生成过程进行动力学分析计算，说明机械能输入对絮团生成的影响。为了验证机械能输入对絮团生成的影响，通过沉降试验，证实机械能输入对絮团效率的作用，发现搅拌速度在500~2 000 r/min时，絮团效率迅速增加，在2 000 r/min时达到峰值，此后搅拌速度增加絮团效率基本稳定,无明显变化；通过分析金相显微镜拍摄的絮团图片，证实机械能输入对絮团形态的作用，发现絮团的结构随着机械能的输入由松散逐渐紧实，而机械能输入过量后，絮团结构又重新被破坏，最终成为疏松的链状絮团；通过常规浮选法，证实不同机械能输入对超净煤品质的作用，发现在搅拌速度为2 000 r/min时，超净煤产品产率最高，灰分最低。

Effect of mechanical energy input on formation of flocculation in ultra-clean coal separation

In order to study the formation mechanism of flocculation by mechanical energy input in ultra-clean coal preparation process,the input of mechanical energy,which can overcome the energy barrier between coal particles to form flocculation,is investigated by using the extended DLVO theory to calculate the potential energy of fine coal particles and draw the potential energy curve.The effect of mechanical energy input on flocculation is confirmed by analyzing and calculating the formation of flocculation kinetic process.In order to test the reliability of the theoretical analysis part,the effect of mechanical energy input on the efficiency of the group was confirmed by using sedimentation experiment,the effect of mechanical energy input on the morphology of the flocculation was confirmed by using the optical microscope and the effect of different mechanical energy input on the quality of ultra clean coal was confirmed by using conventional flotation method.The conclusion is that the Ec increases rapidly with the increase of stirring speed when the speed changes from 500 r/min to 2 000 r/min and basically does not change when the stirring speed continues to increase.The structure of flocculation changes from loose to compaction with mechanical energy input and becomes loose chain after the overdose mechanical energy input destroying the structure of the flocculation.The highest yield and the lowest ash content of ultra-clean coal is found when the stirring speed reaches 2 000 r/min.