本文關(guān)鍵詞： 柱浮選 煤粒 細(xì)泥 污染機(jī)理 抑制　出處：《中國礦業(yè)大學(xué)》2016年博士論文　論文類型：學(xué)位論文

【摘要】：高灰細(xì)泥污染導(dǎo)致浮精灰分超標(biāo)是煤泥浮選亟待解決的難題。本論文針對柱浮選過程中細(xì)泥污染問題,分析了工業(yè)浮選柱精煤中污染礦物特性,探究了細(xì)泥對疏水煤粒浮選行為的影響及細(xì)泥回收規(guī)律,研究了浮選柱內(nèi)煤粒與細(xì)泥的分布規(guī)律和細(xì)泥污染精煤的機(jī)理,提出了減少細(xì)泥污染的措施。主要研究成果如下:闡明了工業(yè)浮選柱精煤中污染礦物的粒度特性、礦物組成。浮精中+0.045 mm粒級灰分一般達(dá)標(biāo),但-0.045 mm粒級灰分遠(yuǎn)不達(dá)標(biāo);浮精中細(xì)泥含量一般小于5%,卻是導(dǎo)致浮精灰分超標(biāo)的主要原因;細(xì)泥顆粒的平均粒徑為10-20μm,其中-20μm粒級含量大于60%,且粒度越小越易污染精煤;細(xì)泥的礦物組成主要為親水的粘土類礦物和石英礦物。研究了細(xì)泥對低灰煤粒浮選行為的影響及細(xì)泥的回收規(guī)律。細(xì)泥與不同粒級低灰煤�；旌细∵x與低灰煤粒單獨浮選相比,細(xì)泥質(zhì)量比例小時能提高低灰煤粒的回收率,反之降低其回收率,且低灰煤粒的粒度越大,回收率降低越明顯;細(xì)泥質(zhì)量比例小時可提高0.5-0.25 mm粒級低灰煤粒的浮選速率常數(shù),反之降低其浮選速率常數(shù);不同質(zhì)量比例下,細(xì)泥主要提高0.25-0.125 mm粒級低灰煤粒的浮選速率常數(shù),但降低0.125-0.074mm粒級低灰煤粒的浮選速率常數(shù)。然而,同一粒級低灰煤粒的浮選速率常數(shù)均隨細(xì)泥質(zhì)量比例增大而減小,表明細(xì)泥質(zhì)量比例增大將減小低灰煤粒的浮選速度。低灰煤粒的浮選速度符合一級矩陣分布模型,細(xì)泥顆粒的浮選速度符合二級矩陣分布模型。細(xì)泥顆粒與低灰煤�；旌细∵x時,細(xì)泥顆粒的主要回收方式為水流夾帶,細(xì)泥的回收率隨細(xì)泥質(zhì)量比例增大而增大。揭示了浮選柱內(nèi)煤粒與細(xì)泥顆粒的分布規(guī)律。采用自制浮選柱研究了批處理與連續(xù)分選工況下低灰煤粒與細(xì)泥顆粒的軸向分布規(guī)律。批處理工況下,從泡沫區(qū)頂部至底部,低灰煤粒的濃度差異小,分布較均勻;細(xì)泥顆粒的濃度明顯呈增大趨勢。從礦漿區(qū)頂部至底部,低灰煤粒的濃度先增大后減小,但礦漿區(qū)底部濃度最大;細(xì)泥顆粒的濃度呈增大趨勢。連續(xù)分選工況下,從泡沫區(qū)頂部至底部,低灰煤粒的濃度差異小,分布較均勻;細(xì)泥顆粒的濃度明顯呈增大趨勢。從礦漿區(qū)頂部至底部,低灰煤粒的濃度先增大后減小,細(xì)泥顆粒的濃度逐漸增大。對比批處理與連續(xù)分選工況下顆粒的分布規(guī)律,泡沫區(qū)內(nèi)的低灰煤粒、細(xì)泥顆粒分布規(guī)律相同;礦漿區(qū)內(nèi)低灰煤粒分布規(guī)律不同,但細(xì)泥顆粒分布規(guī)律相同。通過采集工業(yè)旋流微泡浮選柱軸向、徑向不同點的物料,探究了樣品灰分、細(xì)泥顆粒的分布規(guī)律。軸向上,從泡沫區(qū)到捕集區(qū)再到旋流礦化區(qū),細(xì)泥顆粒的含量整體呈增大趨勢,不同分選區(qū)域內(nèi)細(xì)泥顆粒的含量差異明顯,但捕集區(qū)內(nèi)細(xì)泥顆粒的含量變化規(guī)律不明顯;徑向上,從中心至周邊,泡沫區(qū)內(nèi)細(xì)泥顆粒的含量明顯呈減小趨勢,捕集區(qū)內(nèi)細(xì)泥顆粒的含量變化規(guī)律不明顯,旋流礦化區(qū)內(nèi)細(xì)泥顆粒的含量明顯呈增大趨勢。工業(yè)浮選柱內(nèi)各點樣品灰分分布規(guī)律與細(xì)泥含量分布規(guī)律具有相關(guān)性。工業(yè)浮選柱軸向細(xì)泥顆粒的分布規(guī)律與實驗室浮選柱內(nèi)細(xì)泥顆粒的分布規(guī)律一致。闡釋了細(xì)泥污染精煤的機(jī)理。采用高速動態(tài)攝影儀、實時在線顆粒錄影顯微技術(shù)(PVM)、誘導(dǎo)時間測定儀證實了細(xì)泥的氣泡尾渦夾帶回收機(jī)制、氣泡邊界層粘附回收機(jī)制以及細(xì)泥罩蓋回收機(jī)制,并提出了多氣泡液流攜帶回收機(jī)制。氣泡尾渦夾帶回收機(jī)制不具有選擇性,微細(xì)煤粒與礦物顆粒均可通過該機(jī)制回收;顆粒粒度越小,氣泡尾渦夾帶現(xiàn)象越明顯。微細(xì)礦物顆粒與氣泡的粘附時間與相同粒級疏水煤粒與氣泡的粘附時間差異不大,表明微細(xì)礦物顆粒確實可以粘附在氣泡表面而跟隨氣泡運動。然而,粒度大于0.125 mm的礦物顆粒與氣泡的粘附時間大于5000 ms,表明粒度較粗的礦物顆粒不與氣泡粘附。微細(xì)礦物顆粒粘附氣泡的本質(zhì)是進(jìn)入氣泡表面液膜而跟隨氣泡運動的行為,與疏水煤粒穿破氣泡表面液膜真正粘附氣泡的行為具有本質(zhì)區(qū)別。在多氣泡連續(xù)上浮體系中,細(xì)泥顆粒還可通過多個氣泡的協(xié)同攜帶方式回收,定義為多氣泡液流攜帶回收機(jī)制,其本質(zhì)是水流夾帶機(jī)制的一種具體形式。細(xì)泥顆�？稍趬K精煤表面形成罩蓋現(xiàn)象,且高嶺石顆粒最易形成罩蓋,方解石顆粒在粗糙的塊精煤表面也存在罩蓋現(xiàn)象,而石英顆粒則很難罩蓋在塊精煤表面。提出了泡沫區(qū)內(nèi)置傾斜板、多點組合充氣、礦漿稀釋和添加泡沫噴淋水4種減少柱浮選過程中細(xì)泥污染的措施。試驗結(jié)果表明,上述4種措施均可有效降低浮精灰分,改善煤泥的浮選效果。
[Abstract]:High ash slime flotation concentrate ash pollution leads to exceed the standard problem of coal slime flotation to be solved. This thesis focuses on the problem of pollution of fine mud flotation process, analyzed the pollution characteristics of industrial minerals in coal flotation column, explores the effects of fine mud flotation behavior of hydrophobic coal particles and slime recovery law, study the mechanism of flotation column in the coal slime and the distribution and pollution of coal slime, proposed to reduce the fine mud pollution measures. The main results are as follows: to clarify the characteristics of grain size, mineral flotation column in coal industrial pollution. The mineral composition of +0.045 mm grade float ash general standard, but the -0.045 mm particles of ash far standard; float in fine silt content is generally less than 5%, is the main cause of float ash exceed the standard; the average particle size of 10-20 fine particles M, which -20 m particle content is more than 60%, and the smaller the particle size of the coal slime pollution; The main mineral composition of hydrophilic clay minerals and quartz minerals. The recovery law effects of fine mud on low ash coal particle flotation behavior and slime. Fine mud with different particle level low ash coal particle mixed flotation compared with low ash coal slime flotation particles alone, the proportion of hours can improve the recovery quality low ash coal particles rate, and reduce the recovery rate, particle size and particle low ash coal is bigger, the recovery rate decreased more obviously; the proportion of fine quality hours can improve the flotation rate constant 0.5-0.25 mm grade low ash coal particles, and reduce the flotation rate constant; different quality ratio, improve fine mud flotation rate constant 0.25-0.125 mm particle low ash coal particle level, but reduce the flotation rate constant of 0.125-0.074mm grade low ash coal particles. However, the flotation rate constant with the same grain size increased with the proportion of low ash coal particle slime quality increases, that the proportion of fine quality Increase will reduce the flotation rate low ash coal particles. The flotation rate low ash coal particle accords with the first-order matrix distribution model, the flotation rate fine mud particles with two stage matrix distribution model. Fine clay particles and low ash coal particle mixed flotation, the main way for the recovery of fine mud particles entrained flow, the recovery rate with fine mud the proportion of fine quality increases. The distribution of coal particles and fine particles flotation column. Using the self-made flotation column of batch and continuous separation under the condition of low ash coal slime particles and particle axial distribution. Batch processing conditions, from top to bottom foam area, low concentration difference ash particle is small, uniform distribution; concentration of fine mud particles significantly increased. From the top to the bottom area of pulp, low ash coal particle concentration increased firstly and then decreased, but the concentration of the maximum concentration area at the bottom of the pulp; fine mud particles increased. Continuous separation conditions, from the top to the bottom of the bubble zone, the concentration difference of low ash coal particle size, uniform distribution; concentration of slime particles obviously increased. From the top to the bottom area of pulp, low ash coal particle concentration increases and then decreases the concentration of fine mud particles increases gradually. Compared the distribution of particle number treatment with continuous separation conditions, the foam within the area of low ash coal slime particle, particle size distribution of the same area of low ash coal slurry; particle distribution is different, but the fine particle size distribution of the same industry. Through the acquisition of axial swirl micro bubble flotation column, the material of different points on the radial distribution of the ash samples. Fine clay particles. The axial direction from the bubble zone to the trapping zone to the cyclone mineralized area, content of fine mud particles showed an increasing trend, the difference of content of fine particles of different separation region is obvious, but the trapping zone containing fine mud particles The amount of variation is not obvious; the radial direction, from the center to the periphery, the content of fine particle bubble area was decreased, the changing rule of the contents in the trapping area of fine mud particles is not obvious, the content of fine particles in cyclone mineralization area was significantly increased. The industrial flotation column of each point in the distribution of ash samples law and fine silt content distribution is consistent correlation. Distribution of industrial flotation column axial fine mud particle distribution and laboratory flotation column in fine clay particles. The mechanism explains the slime coal pollution. Using high-speed dynamic camera, real-time video microscopy on line particle (PVM), confirmed the fine measuring instrument mud bubble wake entrainment recovery mechanism of induction time, recovery mechanism of bubble boundary layer and adhesion of fine mud cover recovery mechanism, and puts forward the multi bubble flow carrying recovery mechanism. Bubble wake entrainment mechanism has not recovered Selective, coal particle and mineral fine particles can be recovered through the mechanism; particle size is smaller, the bubble wake entrainment phenomenon is more obvious. The adhesion time of fine mineral particles and bubbles with the same size and hydrophobic coal particles bubble adhesion time difference, that fine mineral particles can adhere to the surface of the trailing bubble bubble sports. However, the adhesion time of mineral particles and bubble size is greater than 0.125 mm greater than 5000 ms, indicating that the mineral particle size of coarse and fine mineral particles. The essence of bubbleattachment adhesion bubble is into the bubble liquid film on the surface and follow the bubble movement behavior, has the essential difference with the hydrophobic coal particles through the bubble liquid film on the surface of real adhesion the behavior of bubbles. The bubbles floating in the continuous system, fine clay particles may also be carried through collaborative way to recycle multiple bubbles, as many articles back to the definition of bubble flow This mechanism, its essence is a specific form of water entrainment mechanism. Fine clay particles can be formed in blocks of coal surface cover, and kaolinite particles formed most easily cover, calcite grains also exist in the block coal surface roughness, and quartz particles are difficult to cover on the surface. The inclined coal block foam district built board, multi-point combination inflatable, slurry adding foam spray water dilution and fine mud pollution 4 reduction measures in the process of flotation column. The experimental results show that the above 4 measures can effectively reduce float ash, improve the effect of slime floatation.

【學(xué)位授予單位】：中國礦業(yè)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：TD94;TD923
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本文編號：1457892