新型双层浮选柱分选宽粒级煤粉试验研究

发布时间：2018-08-23 09:03

【摘要】：选煤厂煤泥常采用0.5 mm分级,大于0.5 mm采用重力分选,小于0.5 mm煤泥采用浮选。但由于煤泥离心机筛篮破损等原因,离心液和磁选尾矿中常常含有较多粗粒精煤,加之分级设备(比如分级旋流器)分级效率不可能达到100%,导致入浮煤泥中含有较多粗粒精煤,传统的浮选机和浮选柱都不能很好的回收这部分煤泥。本论文在旋流微泡浮选柱(FCMC)基础上,运用串联浮选的思想,构建了新型双层浮选柱试验系统,由一段短体充气式浮选柱和二段FCMC组成。通过析因试验和正交试验,探索了一段充气量、入料浓度、捕收剂用量、循环压力对浮选效果的影响规律,确定了较佳工艺参数。在相同工艺条件下,对比浮选机、FCMC和新型双层浮选柱对宽粒级煤粉的浮选效果,探究新型双层浮选柱提高粗粒煤泥回收率的可行性。试验采用宽粒级煤样(0.7~0 mm),新型双层浮选柱试验结果表明:在相同一段充气量、相同入料浓度下,随着循环压力增大,总精煤产率和灰分逐渐增大,循环压力为0.14MPa时,浮选完善指标较高;在相同一段充气量、相同循环压力下,随着入料浓度升高,总精煤产率和灰分呈增大趋势,浮选完善指标先增大后减小;在相同入料浓度、相同循环压力下,随着一段充气量增大,二段精煤产率逐渐减小,二段精煤灰分呈增大趋势,总精煤灰分也增大,一段充气量为0.05 m3/h时,浮选完善指标最大。入料浓度、捕收剂、一段充气量对总精煤产率影响均较显著,入料浓度、一段充气量、捕收剂对总精煤灰分影响均较显著,入料浓度对浮选完善指标影响显著。相同工艺条件下,对于0.7~0.25 mm粒级,FCMC回收率(占本级)为51.85%,灰分为5.91%,浮选机比FCMC回收率高3.77%,灰分高0.59%;新型双层浮选柱比浮选机回收率高4.06%,灰分下降0.43%。新型双层浮选柱尾煤中低密度物(-1.5 kg/L)含量比浮选机、FCMC低,高密度级(+1.5 kg/L)灰分比FCMC、浮选机高,然而新型双层浮选柱精煤中高密度级(+1.5 kg/L)含量比FCMC和浮选机略高。新型双层浮选柱通过两段浮选,有效提高了粗粒精煤的回收率。与浮选机、FCMC相比,新型双层浮选柱浮选粗粒含量较多的煤泥时,对粗颗粒的回收率更高。
[Abstract]:Coal slime in coal preparation plant is usually classified by 0.5 mm, gravity separation is used for more than 0.5 mm, and flotation is used for slime less than 0.5 mm. However, due to the breakage of the sieve basket of the slime centrifuge, the centrifugal fluid and magnetic separation tailings often contain more coarse-grained refined coal, and the classification efficiency of the classifying equipment (such as the classifying cyclone) cannot reach 100%, which results in the inclusion of more coarse-grained coal in the floating slime. The traditional flotation machine and flotation column can not recover this part of coal slime very well. On the basis of (FCMC), a new double-layer flotation column test system is constructed by using the idea of series flotation. The system is composed of a short-body aerated flotation column and a two-stage FCMC. By means of factorization test and orthogonal test, the effects of charge volume, feed concentration, collector dosage and circulation pressure on flotation effect were investigated, and the better technological parameters were determined. Under the same technological conditions, the flotation effects of FCMC and a new double-layer flotation column on wide-grained pulverized coal were compared, and the feasibility of the new double-layer flotation column to increase the recovery rate of coarse coal slime was explored. The test results of a new double-layer flotation column with wide grain size (0.7 ~ 0 mm),) showed that the total clean coal yield and ash content increased with the increase of circulation pressure at the same aeration rate and the same feed concentration, and when the circulation pressure was 0.14MPa, the total clean coal yield and ash content gradually increased with the increase of circulation pressure. The improvement index of floatation is higher, the total clean coal yield and ash content increase with the increase of feed concentration under the same aeration volume and the same circulation pressure, and the flotation consummation index increases first and then decreases, and at the same feed concentration, the total clean coal yield and ash content increase at the same feed concentration. Under the same circulation pressure, the yield of the second stage of clean coal decreases gradually with the increase of the aeration rate of the first stage, the ash content of the second stage of the clean coal increases, and the total ash content of the clean coal increases, and the flotation consummation index is the largest when the air volume of the first stage is 0.05 m3 / h. The effect of feed concentration, collector and first stage aeration rate on the total clean coal yield is significant. The feed concentration, the first stage aeration rate and the collector have significant effects on the ash content of the total clean coal, and the feed concentration has a significant effect on the flotation consummation index. Under the same technological conditions, the recovery rate of 0.70mm 0.25mm particle grade FCMC is 51.85, the ash is 5.91, the floatation machine is 3.77g higher than FCMC, and the ash content is 0.59.The new double-layer flotation column has a higher recovery rate of 4.06g and a decrease of 0.43. The content of low density (-1.5 kg/L) in the new double-layer flotation column tail coal is lower than that in flotation machine. The ash content of high density grade (1.5 kg/L) is higher than that of FCMC and flotation machine. However, the content of high density grade (1.5 kg/L) in the new double-layer flotation column coal is slightly higher than that in FCMC and flotation machine. The new double-layer flotation column can effectively improve the recovery rate of coarse-grained clean coal by two-stage flotation. Compared with floatation machine FCMC, the recovery rate of coarse particles is higher when the coal slime with more coarse particles is floated by the new double-layer flotation column.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD94

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