充气旋流浮选柱充气性能对煤泥粒度影响研究

发布时间：2018-03-01 07:20

本文关键词： 充气旋流浮选柱充气量粒度组成浮选动力学浮选效果　出处：《中国矿业大学》2017年硕士论文　论文类型：学位论文

【摘要】：针对当前浮选工艺中加强粗粒物料的回收,造成高灰细泥在泡沫产品中的机械夹带,导致细精煤灰分偏高;相反,降低细泥对精煤灰分的影响,又导致部分粗粒精煤损失在尾煤中,而传统浮选设备难以对粗细煤泥同时实现有效分选,结合旋流浮选柱和充气浮选柱的优点,开展了充气旋流浮选柱充气性能对煤泥粒度影响研究,通过经典动力学对不同粒级煤泥的浮选动力学过程进行了探究。充气旋流浮选柱煤泥浮选试验研究对于提高全粒级煤泥浮选效果具有非常重要的意义,0.5-0.25mm粒级煤泥,柱体从下到上,产率逐渐降低,而0.125-0.074mm和-0.074mm粒级,其产率逐步增加,处于中间的0.25-0.125mm粒级煤泥,低充气量下,产率随柱体高度变化不明显,充气量达到一定程度时,产率波动较大,总体呈上升趋势;煤泥灰分随柱体高度的升高而降低,柱体上浮选段煤泥灰分梯度相比中、下浮选段更大,而且充气量越高,灰分梯度越明显;精煤筛分结果发现,充气量由0.25m3/h提高到1.0m3/h时,0.5-0.25mm和0.25-0.125mm煤泥回收率加和从15.20%增至39.35%,而0.125-0.074mm和-0.074mm粒级煤泥增幅则缓慢很多。充气旋流浮选柱不同粒级煤泥浮选动力学研究发现,增加充气量能显著提高各粒级煤泥的浮选速度常数,浮选早期阶段,细粒级煤泥(0.25-0.074mm)浮选速度最快,随着时间延长,粗粒级煤(0.5-0. 25mm)浮选速度优于细粒级,且回收率更高,通过增加充气量可提高粗粒煤泥在充气旋流浮选柱中的分选效果。对充气旋流浮选柱各粒级煤泥浮选动力学试验结果进行了拟合,0.25m3/h充气量下,0.5-0.25mm煤泥符合经典一级动力学模型,0.5m3/h和0.75m3/h充气量时,一级矩形分布模型符合度最高,1.0m3/h充气量下,二级动力学模型拟合度最好;而0.25-0.074mm和-0.5mm煤泥,充气量为0.75m3/h时,符合一级矩形分布模型,其他充气量下,浮选过程二级动力学模型匹配度最高;建立了适合描述不同充气量下各粒级煤泥浮选过程的新动力学模型,其表达式为:式中a、b、c、d为相关参数,通过验证,该模型具有较高的可靠性。充气旋流浮选柱提高充气量能明显改善煤泥的分选效果,可实现对粗粒煤泥的有效回收,对于工业应用有一定的借鉴意义。
[Abstract]:In view of strengthening the recovery of coarse grain materials in the current flotation process, the mechanical entrainment of high ash and fine mud in foam products leads to higher ash content of fine clean coal, on the contrary, reducing the influence of fine mud on ash content of clean coal, However, it is difficult for traditional flotation equipment to realize effective separation of coarse and fine slime at the same time, which combines the advantages of swirl flotation column and aerated flotation column. The effect of aeration performance on the particle size of coal slime was studied. The flotation kinetics of coal slime with different particle size was studied by classical kinetics. The experimental study on flotation of coal slime with aerated swirl flotation column is of great significance for improving the flotation effect of coal slime with full particle size of 0.5-0.25mm. From the bottom to the top, the yield of the column gradually decreased, while the yield of 0.125-0.074mm and -0.074mm increased gradually, and the coal slime of 0.25-0.125mm was in the middle. Under the condition of low aeration, the yield did not change obviously with the height of the column, and when the aeration reached a certain degree, the yield fluctuated greatly. As a whole, the ash content of coal slime decreases with the increase of column height. Compared with the gradient of ash content in the column flotation section, the lower section is larger, and the higher the amount of aeration, the more obvious the ash gradient is. When the aeration rate increased from 0.25 m3 / h to 1.0m3 / h, the recoveries of 0.5-0.25mm and 0.25-0.125mm slime increased from 15.20% to 39.35mm, while the increase of 0.125-0.074mm and -0.074mm granular slime was much slower. At the early stage of flotation, the floatation rate of fine coal slime is the fastest. With the increase of time, the flotation rate of coarse grained coal is better than that of fine coal, and the recovery rate is higher. The separation effect of coarse coal slime in aerated swirl flotation column can be improved by increasing the amount of aeration. The flotation kinetic test results of each particle grade slime of aerated swirl flotation column are fitted with the results of 0.25m3 / h aeration volume and 0.5-0.25mm coal slime accords with the classical first order. When the kinetic model is 0.5 m3 / h and 0.75 m3 / h, The fitting degree of the second-order dynamic model is the best when the consistency of the first-order rectangular distribution model is the highest (1.0 m3 / h), but when 0.25-0.074 mm and -0.5 mm slime, the aeration rate is 0.75 m3 / h, it accords with the first-order rectangular distribution model and other inflatable quantities. A new dynamic model is established to describe the flotation process of coal slime with different amount of aeration. The expression of the model is as follows: a / B / C / d is the relevant parameter, and it is verified that the model can be used to describe the flotation process of coal slime. The model has a high reliability and can obviously improve the separation effect of coal slime by increasing the aeration volume of the aerated swirl flotation column, and can realize the effective recovery of coarse coal slime, which has certain reference significance for industrial application.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD94;TD923

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