脉动粗煤泥分选机分选理论及其应用研究

Separation theory and applied research of coarse coal slime pulsation separator

为改善粗煤泥的分选效果,结合国内外较细颗粒矿物分选技术和粗煤泥难选的特点,确定采用脉动方式即跳汰方式分选粗煤泥。介绍了主要的跳汰分选学说,研究了脉动水流作用下的跳汰分层理论,从颗粒受力出发,形成了跳汰分层机理的新学说。重力、浮力和压力梯度力是跳汰分层的本质力,其中压力梯度力是可变的,是跳汰分层的根本动力。对跳汰分层过程进行了重新认识,确定跳汰分层主要发生在水流上升末期。在新学说的指导下,明确了粗煤泥分选应具备的条件,研发出新型无风源脉动粗煤泥分选机,并以此指导生产操作。简要介绍了脉动粗煤泥分选机的结构和工作原理。生产实践表明,脉动粗煤泥分选机的分选效果好,分选下限达到0.25 mm,对-0.25 mm的细煤泥也有较好的分选效果。

In order to improve the separation effect of Coarse coal slime,according to domestic and international technology of mineral separation of finer particles and coarse coal slime,this paper applied the method of pulsation,otherwise known as jigging,to separate the coarse coal slime. Based on the introduction of the main theories of jigging separation,the stratification theory of jigging concerning pulsation current of water and analysis of force on the particles,the new theory of jigging stratification mechanism was illustrated. There is a theory that gravity,buoyancy and pressure gradient force contribute to the jigging separation. Moreover,the pressure gradient force is variable which is the fundamental driving force of jigging stratification mechanism. Recognition of the jigging separation process indicate that jigging stratification takes place mainly at the end of the upward water flow. On the basis of the new theory of jigging stratification,the proper conditions of coarse coal slime separation have been explicited,a new type of coal slime pulsation separator without wind source has been designed to guide production operation. After the brief introduction of the new coarse coal slime separator structure and working principle. Experiments show that the new coarse coal slime separator meet our requirements. Moreover,results of the separator prove that not only lower limit of separation can achieve at0. 25 mm,but also the separation effect is ideal in terms of particles with size of- 0. 25 mm.