煤泥絮团分选超净煤的试验研究

为探索处理动力煤选煤厂煤泥的新途径，以动力煤选煤厂煤泥为研究对象，分析了煤泥的性质、煤泥中矿物质的种类和嵌布特征，通过分步释放浮选试验考察了该煤泥的理论精煤产率和灰分，分析了煤泥经超细粉碎后分选超净煤的可行性。基于扩展DLVO（EDLVO）理论，论证了絮团浮选前采取高剪切搅拌的必要性，研究了高速搅拌对颗粒和药剂之间的促进作用。采用絮团浮选方法，对超细粉碎后的煤泥进行了超净煤分选试验，探讨了高剪切搅拌叶轮线速度、搅拌时间、煤泥粒度和非极性油用量与分选效果的关系。试验结果表明，只有在高速搅拌的情况下超细粉碎后的煤泥颗粒才能形成絮团，并且在与药剂作用后，降低了需要输入的搅拌功耗；高速搅拌还可以促进药剂的分散，从而增加药剂与煤颗粒的碰撞概率；若要达到较好的絮团分选效果，需要一定程度的搅拌强度和适当的搅拌时间。当粉碎平均粒度为4.70 μm、非极性油用量为135.24 kg/t、叶轮线速度为12.56 m/s、搅拌时间5 min时，分选出的超净煤灰分达到1.15%，产率为69.23%。

Experimental study on flocculation flotation of ultra-clean coal from slime

In order to explore new ways of processing coal slime in the steam coal preparation plant，the coal slime of thermal coal preparation plant was investigated in this study，including the properties of coal slime，mineral types and dissemination characteristics in coal slime.A regressive release flotation test was designed for theoretically investigating the ash and yield of low ash clean coal.The feasibility of ultra-clean coal separation after super fine crushing was analyzed.Based on the extended DLVO (EDLVO) theory，the necessity of high shear stirring for the ultra-fine grinding slime before flocculation flotation was attested.Also，the acceleration effect of high speed stirring between particle and reagent was studied.With the flocculation flotation method，the ultra-clean coal separation of the slime after ultra-fine grinding were carried out.The effect of mixer impeller linear speed and stirring time，particle size，non-polar oil dosage on the separation results were discussed.The separation results show that the floccules can form capably only in the case of high speed stirring，and the power consumption is reduced after the action between coal particle and non-polar oil.High-speed stirring can also promote the dispersion of agent，then the collision probability of agent and coal particle is increased.A better flocculation separation requires a certain degree of stirring intensity and an appropriate stirring time.When the average particle size is 4.70 μm，non-polar oil dosage is 135.24 kg/t，the impeller linear speed is 12.56 m/s，and the stirring time is 5 min，the ash of ultra-clean coal separated reaches 1.15%，and the yield reaches 69.23%.