药剂及格条作用下煤泥螺旋溜槽分选规律研究

发布时间：2018-02-03 09:59

本文关键词： 螺旋溜槽煤泥药剂格条精煤灰分数值模拟　出处：《太原理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：为降低螺旋溜槽精煤产品灰分及其分选密度，提高螺旋溜槽精煤产率及其综合分选效率，进行了普通界面煤泥螺旋溜槽分选规律试验、药剂作用下普通界面煤泥螺旋溜槽分选规律试验以及格条作用下煤泥螺旋溜槽分选规律试验。利用流体模拟软件Fluent分别对无格条螺旋溜槽和格条螺旋溜槽的流场进行了数值模拟，计算模拟结果较好的解释和验证了试验结果。增大给料旋流器底流口直径和入料压力，螺旋溜槽各粒级精煤灰分升高，同时各粒级尾煤灰分、精煤产率及综合效率也均升高，说明矿浆流量和入料浓度大小对螺旋溜槽分选效果影响较大。聚乙二醇400、仲辛醇和煤油分别作用下，随着药剂添加量的增加，各粒级精煤灰分和综合效率不断降低，除最细0.074mm粒级精煤产率升高外，其他粒级精煤产率均不断降低，说明三种药剂分别作用下可有效降低螺旋溜槽精煤产品灰分，但综合分选效果变差；煤油和仲辛醇共同作用下可降低粗粒级精煤灰分，没有两种药剂单独作用下效果好，但能提高细粒级分选效率。 2mm和3mm高度格条分别作用下，随着格条数量的增加，粗粒级精煤灰分不断降低，且后者降灰效果优于前者，各粒级精煤产率和综合效率均逐渐降低，4mm高度格条作用下粗粒级精煤灰分先降后升，可提高最粒级精煤产率，各粒级综合效率变化不大。格条外缘固定正角度时，3mm和4mm格条分别作用下各粒级精煤灰分和精煤产率显著上升，在45°达到最大值，可提高粗粒级分选效率，但细粒级分选效率降低；负角度时两种格条可降低粗粒级精煤灰分，同时精煤产率和综合效率降低，而4mm高度格条可提高细粒级精煤产率，这一点优于3mm高度格条，3mm高度格条作用下各粒级综合效率降幅较大，4mm高度格条变化较小。格条内缘固定正角度时，粗粒级精煤灰分、尾煤灰分、精煤产率和综合效率均降低，且角度越小降幅越大，细粒级精煤灰分和精煤产率升高，尾煤灰分和综合效率降低；负角度时各粒级精煤灰分、尾煤灰分、精煤产率和综合效率均比无格条时高。无格条螺旋溜槽流场模拟结果显示，螺旋溜槽槽面上的水流沿外缘运动，存在二次环流，内缘严重失水，这同光槽面螺旋溜槽实际流场相一致；铺设有8条向内缘导流螺旋溜槽流场模拟结果显示，槽面上流体遇到格条后，，明显向内移动，在槽面上覆盖面积显著增大，外缘水层变薄，同试验现象吻合，这也是精煤灰分和精煤产率降低的主要原因。螺旋溜槽是较好的粗煤泥分选设备，合理确定药剂制度和格条操作参数可达到降低螺旋溜槽精煤灰分和提高螺旋溜槽精煤产率和分选效率的目的。
[Abstract]:In order to reduce ash content and separation density of spiral chute clean coal product and improve the yield of spiral chute coal and its comprehensive separation efficiency, the separation law of common interface coal slime spiral chute was tested. The separation laws of common interface slime spiral chute and slime spiral chute under the action of fungicide and the slime spiral chute under the action of lattice strip were tested respectively by using the fluid simulation software Fluent. The flow field of the chute is simulated numerically. The experimental results are well explained and verified by the simulation results. With the increase of feed hydrocyclone bottom outlet diameter and feed pressure, the ash content of each grade of clean coal in spiral chute is increased, and the ash content of each grade of coal tail coal, the yield of clean coal and the comprehensive efficiency are also increased. The results show that slurry flow and feed concentration have great influence on the separation effect of spiral chute. Under the action of polyethylene glycol 400, para-octanol and kerosene, the ash content and comprehensive efficiency of each fine coal decreased with the increase of the amount of chemicals added, except that the yield of the finest 0.074 mm fine coal increased. The production rate of other fine coal has been decreasing, which shows that the ash content of spiral chute coal can be reduced effectively under the action of three kinds of chemicals respectively, but the comprehensive separation effect becomes worse. Coal oil and para-octanol can reduce the ash content of coarse-grained clean coal. The effect is good without two kinds of medicament alone, but it can improve the separation efficiency of fine grained coal. Under the action of 2 mm and 3 mm height bar respectively, with the increase of the number of the bars, the ash content of the coarse grained clean coal decreases continuously, and the ash reduction effect of the latter is better than that of the former, and the yield and comprehensive efficiency of each grain grade clean coal decrease gradually. Under the action of 4mm height bar, the ash content of coarse-grained clean coal decreases first and then rises, which can increase the yield of the most granular clean coal, and the comprehensive efficiency of each grain-grade coal does not change much. Under the action of 3mm and 4mm bars respectively, the ash content and the yield of clean coal increased significantly, and reached the maximum value at 45 掳, which can improve the separation efficiency of coarse grain. However, the separation efficiency of fine particles was decreased. When the angle is negative, the ash content of coarse-grained clean coal can be reduced, while the yield and comprehensive efficiency of clean coal can be reduced, while the yield of fine grained clean coal can be increased by 4mm height bar, which is better than that of 3mm height bar. Under the action of 3mm height bar, the decrease of the comprehensive efficiency of each grain level is larger than that of the 4mm height bar. When the inner edge of the grid is fixed at a straight angle, the ash content of the coarse grained clean coal and the coal ash content of the tail coal are fixed. The yield and comprehensive efficiency of clean coal are both decreased, and the smaller the angle is, the bigger the decrease is, the higher the ash and the yield of fine coal are, the lower the coal ash content and comprehensive efficiency of tail coal are. The ash content, tail coal ash content, clean coal yield and comprehensive efficiency are higher at negative angle than those without grid. The simulation results show that the flow on the helical chute surface moves along the outer edge with secondary circulation and serious loss of water in the inner edge, which is consistent with the actual flow field of the helical chute on the optical slot surface. The flow field simulation results show that the fluid on the slot surface moves inward obviously after it meets the grid, and the coverage area on the groove surface increases significantly, and the water layer on the outer edge becomes thinner, which coincides with the experimental phenomenon. This is also the main reason for the decrease of ash and yield of clean coal. Spiral chute is a good equipment for separating coarse coal slime. Reasonably determining the medicament system and the operation parameters of the sliver can reduce the ash content of the spiral chute and improve the yield and separation efficiency of the coals in the spiral chute.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD94

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