新型煤泥水力分选机研究

发布时间：2018-04-04 03:56

本文选题：煤泥水力分选机　切入点：浮选尾煤　出处：《太原理工大学》2016年硕士论文

【摘要】：在煤炭洗选过程中,由于分级设备存在随机性,使得部分粗粒煤进入浮选。而浮选对粗粒煤的分选作用较弱,致使浮选尾煤中粗粒灰分偏低,增加了浮选粗精煤的损失量,浪费了宝贵资源。因此,结合干扰床分选机工作特点,运用干扰沉降原理,设计并制作了一种具有水跃反射装置的新型煤泥水力分选机,规格为Φ=200mm,H=430mm,分析了它的工作原理和特点,将其应用于浮选尾煤再选和粗煤泥分选中。浮选尾煤再选中,分别进行了顶水量和入料浓度对分选效果的影响试验。结果表明,当顶水量为0.44 m3·h-1时,从浮选尾煤中回收了产率23.64%,灰分28.48%的+0.125mm低灰中煤。随着粒度的减小,进入溢流中的产率增加,特别-0.125mm细粒级70%左右产率进入溢流,说明该新型分选设备具有良好分选作用的同时,还起到了一定的分级作用,但过大的顶水量则会起到不利的影响。当入料浓度为180-240g·L-1时,底流各粒级灰分在68%以上,底流精煤损失量少,利于精煤回收。粗煤泥分选中,分别进行了顶水量、入料管插入深度、窄粒级入料和中流通道间隙大小对分选粗煤泥的影响试验。结果表明,该分选设备对粗煤泥有一定的分选效果,可以得到灰分11%的0.25-3mm精煤,而且粒度越粗灰分越小;入料管插入深度越深越好,本机采用167mm较适宜;入料量越大分选效果越差,选取3.5-4.5 m3·h-1较佳;中流通道间隙越小,底流精煤损失越严重,分选精度越差;而中流通道间隙越大,损失到中流的精煤就会增加,对分选也不利,故本机中流通道间隙设为5mm。分选机流场模拟结果表明,入料在反射水跃的作用下,形成了具有一定速度的向上折返流,提供了第一次上升水流;增设顶水提供了第二次上升水流。顶水对底锥内的流场分布影响大,对溢流柱体的影响较小。加大顶水后,大顶水量加大了流场的紊乱程度,不利于颗粒的分选。增大入料量,加剧了流场的紊乱,加快了物料的排出速度,降低了其在机体内的停留时间,不利于颗粒的稳定沉降分离。顶水量模拟和入料量模拟结果与实际带煤试验结果相符合。选取合适的顶水量和入料量很有必要。综上说明,新型煤泥水力分选机一次分选得到三个不同质量指标的产品。对浮选尾煤再选效果良好,可提高粗粒浮选尾煤灰分,是一种良好的粗粒浮选尾煤再选设备;并对不同性质煤泥有一定的适应性。
[Abstract]:In the process of coal washing, some coarse-grained coal come into flotation because of the randomness of classifying equipment.However, flotation has a weak separation effect on coarse-grained coal, which leads to the low ash content of coarse coal in flotation tail coal, which increases the loss of coarse coal in flotation and wastes valuable resources.Therefore, according to the working characteristics of the jammed bed separator and the principle of interference settlement, a new type of coal slime force separator with hydraulic jump reflector is designed and manufactured, the specification of which is 桅 200 mm HX 430mm. The working principle and characteristics of the separator are analyzed.It is applied to flotation tail coal reprocessing and coarse coal slime separation.The effect of top water amount and feed concentration on the separation efficiency of flotation tailings were tested.The results show that when the top water content is 0.44 m3 路h ~ (-1), the 0.125mm low ash medium coal with a yield of 23.64% and ash content of 28.48% has been recovered from the flotation tail coal.With the decrease of particle size, the yield of entering overflow increases, especially the yield of -0.125 mm fine grain grade about 70% enters overflow flow, which shows that the new separation equipment has good separation function, but also plays a certain role in grading.But too much top water will have a negative effect.When the feed concentration is 180-240 g 路L ~ (-1), the ash content of the bottom stream is above 68%, and the loss of the bottom flow clean coal is less, which is beneficial to the recovery of the clean coal.In the separation of coarse coal slime, the effects of top water amount, feed pipe insertion depth, narrow grained feed and middle flow channel clearance on the separation of coarse coal slime were tested.The results show that the separation equipment has a certain separation effect on coarse coal slime, and the ash content of 11% 0.25-3mm clean coal can be obtained, and the coarser ash content is smaller, the deeper the feed pipe is, the better the depth is, and the 167mm is more suitable for this machine.The bigger the feed volume is, the worse the separation effect is, the better is the selection of 3.5-4.5 m3 h-1; the smaller the clearance of the middle flow channel is, the more serious the loss of the bottom flow clean coal is and the worse the separation accuracy is; and the larger the clearance of the middle flow channel is, the more the loss of the refined coal to the middle stream will increase, which is also disadvantageous to the separation.Therefore, the flow channel clearance is set to 5 mm.The flow field simulation results of the separator show that under the action of the reflected water jump, the upward reentrant flow with a certain velocity is formed, and the first upward flow is provided, and the second upward flow is provided by adding the top water.The top water has great influence on the distribution of flow field in the bottom cone, but has little effect on the overflow cylinder.When the top water is increased, the large top water increases the disturbance of the flow field, which is not conducive to the separation of particles.The increase of the feed volume intensifies the disorder of the flow field, speeds up the discharge speed of the material, reduces its residence time in the body, and is not conducive to the stable settling separation of the particles.The simulation results of top water volume and feed rate are in agreement with the actual coal belt test results.It is necessary to select appropriate top water and feed quantity.In summary, three different quality indexes were obtained by a new coal slurry separator.It has good effect on flotation tailings and can improve ash content of coarse flotation tailings. It is a good equipment for flotation of coarse coal and has certain adaptability to different properties of coal slime.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD45

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