【作者】 李洋；

【导师】 谢广元； 朱子祺；

【作者基本信息】 中国矿业大学 ， 资源与环境（专业学位）， 2024， 硕士

【摘要】 新郑精煤公司选煤厂现行工艺存在粗精煤灰分超标、精煤回收率低、浮选精煤灰分偏高和尾煤灰分偏低等问题。本文针对上述问题开展了实验室和工业试验,提出了粗、细煤泥分选工艺改造方案,工艺改造后,保证了选煤厂精煤产品质量。单机检查结果表明,TBS溢流中+0.25 mm粒级精煤灰分13.38%,高于总精煤要求灰分。粗精煤脱泥筛脱泥效果差,存在严重的筛上“夹细”与筛下“跑粗”问题;作为浮选入料的加压过滤机入料掺粗分级浓缩旋流器溢流与脱泥筛筛下水中存在大量粗粒煤泥;浮选机浮选效果差,浮精灰分超标、尾煤的灰分偏低。TBS分选试验结果表明:通过改变TBS的顶水流速能有效降低溢流中+0.25 mm粒级粗精煤灰分。调研国内选煤厂脱泥设备改造案例表明:叠筛比弧形筛有优异的脱泥效果,叠筛替代振动弧形筛可提高脱泥效果。浮选入料正交试验结果表明,影响浮精灰分与浮选完善指标的因素显著性顺序为:药剂用量>矿浆浓度>充气量。浮选机和旋流微泡浮选柱一次浮选试验结果表明,精煤灰分合格时,尾煤灰分偏低。通过调整现场浮选机参数,保证一、二室精煤灰分合格前提下,浮选尾煤灰分从57.62%提高至78.25%。对现场浮选机三、四室精煤分别进行浮选机和浮选柱精选试验,浮选精煤灰分合格,浮选柱精煤产率比浮选机高45.01个百分点。“浮选机粗选+三、四室浮选柱精选”可有效解决浮精灰分超标和浮尾灰分偏低的问题。粗、细煤泥分选工艺改造,TBS溢流中+0.25 mm粒级灰分由13.38%降低至9.69%,粗精煤质量得到明显改善。叠筛分级效率高达85%,有效地解决了筛上“夹细”与筛下“跑粗”问题。“浮选机粗选+三、四室浮选柱精选”工艺在保证浮选精煤灰分合格的前提下,一次浮选尾煤灰分可提升至80%以上。改造后每年可创收近1775万元,投资回收期不到六个月。更多还原

【Abstract】 The current process of the coal preparation plant at Xinzheng Clean Coal Company faces several issues,including excessive ash content in crude clean coal,low recovery rates of clean coal,high ash content in flotation clean coal,and low ash content in tailing coal.This study conducted both laboratory and industrial tests to address these problems and proposed a program to improve the separation processes for coarse and fine coal slimes.Following the process transformation,the quality of the clean coal products at the coal preparation plant was assured.The results of the single machine inspection indicate that the ash content of the+0.25 mm particle size clean coal in the TBS overflow is 13.38%,which exceeds the required ash content for the total clean coal.The desliming effect of the coarse coal desliming screen is inadequate,with significant issues of "fine particles trapped" on the screen and "coarse particles bypassing" below the screen.The flotation feed,which includes the feed from the pressurized filter mixed with the overflow from the coarse classification and concentration cyclone,contains a substantial amount of coarse-grained coal slime from the water under the desliming screen.Additionally,the flotation performance of the flotation machine is suboptimal,resulting in flotation fines with ash content exceeding the standard and tail coal with low ash content.The TBS separation test results indicate that adjusting the top water velocity of the TBS can effectively reduce the ash content of +0.25 mm particle size coarse clean coal in the overflow.Research on desliming equipment transformations in domestic coal preparation plants shows that stacked screens provide better desliming effects than curved screens.Consequently,replacing vibrating curved screens with stacked screens can enhance the desliming performance.The results of the flotation feeding orthogonal test indicate that the factors affecting the flotation ash content and flotation improvement index,in order of significance,are: reagent dosage > slurry concentration > aeration amount.Further tests using a flotation machine and a cyclonic microbubble flotation column demonstrate that when the ash content of the clean coal is within acceptable limits,the ash content of the tailing coal remains low.By adjusting the parameters of the on-site flotation machine to ensure the ash content of the clean coal in the first and second chambers is within acceptable limits,the ash content of the flotation tail coal increased from 57.62% to 78.25%.Selection tests with the flotation machine and flotation column were conducted on the clean coal in the third and fourth chambers of the on-site flotation machine,respectively.The ash content of the flotation clean coal met the required standards,and the yield of the flotation column clean coal was 45.01 percentage points higher than that of the flotation machine.The combined use of a "rough flotation machine and three-and four-chamber flotation column selection" effectively addresses the issue of excessive ash content in the flotation fines and low ash content in the flotation tailings.The coarse and fine coal slime separation processes have been modified,reducing the +0.25 mm particle size ash content in the TBS overflow from 13.38% to9.69%,significantly improving the quality of the coarse clean coal.The classification efficiency of the stacked-type screen has reached 85%,effectively addressing the issues of "fine particles trapped" on the screen and "coarse particles bypassing" below the screen.The process of "flotation machine roughing combined with three-and four-chamber flotation column selection" can increase the ash content of the flotation tail coal to over 80%,while ensuring that the ash content of the flotation clean coal meets the required standards.Following the renovation,the process is projected to generate an annual income of nearly 17.75 million yuan,with an investment payback period of less than six months.更多还原