The Separating And Classifying Cyclone For Coal Slime—Performance And Industrial Application

The three-product separating and classifying cyclone for coal slime (TP-SCC for short) was successifully developed which was based on the coal slime hydrocyclone gravity separation column patented by Taiyuan University of Technology. The equipment can achieve classification and separation at the same time and produce three different kinds of products:fine-grained overflow, side-overflow contains clean coal and high ash underflow. The structural and operating parameters influenced the performance of the TP-SCC were systematically studied. Its effect was assessed under particular structure and the separation effect to flotation tailings was also investigated. The combination experimental research with the multi-product separating and classifying cyclone (MP-SCC for short) constructed on the basis of the experimental results of the TP-SCC was studied. In addition, the MP-SCC was enlarged and applied in industry.The impacts of structural parameters (overflow diameter, depth of overflow tube, side-overflow diameter, sleeve length and cone structure) and operating parameters (inlet pressure and feed concentration) on the TP-SCC were studied. The overflow diameter and side-overflow diameter are the major factors influenced the classifying effect of the TP-SCC. The side-overflow diameter, sleeve length and cone structure are the major factors influenced the separating effect of the TP-SCC. The rule of depth of overflow tube isn’t obvious and it should not be too shallow and too deep. With the increase of inlet pressure, the classifying and separating effects are better. Low feed concentration basically has no influence on the classifying effect, but the classifying effect becomes poor when the concentration exceeds150g/L. The side-overflow ash increases with the increase of feed concentration, and the separating effect becomes poor.The experiment results of flotation tailings showed that the TP-SCC can recover the clean coal lost into the flotation tailings as the scavenging assignment. The effect of the TP-SCC under particular structure was assessed. For the size greater than0.125mm, the possible deviation Ep is indicated to be0.176and the imperfection I about0.266. For the size greater than0.25mm, the possible deviation Ep is indicated to be0.163and the imperfection I about0.258. For the size greater than0.5mm, the possible deviation Ep is indicated to be0.103and the imperfection I about0.19.The experiments were conducted in the different combination structures of the MP-SCC constructed on the basis of the experimental results of the TP-SCC. It shows that the MP-SCC can produce four different kinds of products:fine-grained overflow, side-overflow contains clean coal, middings and high ash gangue, which achieve the desired purpose.The MP-SCC of φ700mm was applied to the coarse coal preparation system in Shuguang coal preparation plant which was enlarged on the basis of the structures of the MP-SCC of φ150mm. It is proved that the system operates properly and economic benefit followed is significant.