高灰细粒难浮煤泥浮选工艺研究

发布时间：2019-03-03 17:28

【摘要】：随着采掘工艺的不断机械化以及优质煤炭的枯竭,出现了大量的高灰细粒煤泥,浮选是处理高灰细粒煤泥最有效的方法之一。高灰细粒难浮煤泥主要是煤粒中掺杂有大量的细粒脉石矿物,在传统浮选过程中,传统烃类捕收剂在捕收煤粒的同时会携带有大量的脉石矿物,造成大量细泥夹带,出现选择性差的问题。同时,由于煤粒表面含有含氧官能团,疏水性差,传统烃类捕收剂难以捕捉到煤粒,所以也会出现捕收性差的问题。在捕收剂中添加适量的表面活性剂可以改善浮选效果,实现煤粒与脉石矿物的高效分离。如何寻找合适的表面活性剂是浮选过程中的一大难题。本文针对高灰细粒煤泥难浮的特性,以聚氧乙烯醚型和烷醇酰胺型非离子表面活性剂与煤油复配、以及形成乳化液来代替单纯使用煤油做捕收剂的浮选工艺,来探究其对煤泥浮选的促进作用。在实验过程中,以神东某选煤厂的煤泥为研究对象,通过浮选实验,对不同类型捕收剂对煤泥的浮选效果进行评定,考察其对浮选的影响情况。另外,采用高剪切调浆预处理技术,比较不同转速和不同调浆时间对浮选的影响。与常规浮选对比,分析高剪切调浆对浮选的影响。然后用红外光谱研究了乳化后捕收剂的增效机理。实验内容以及所得结论如下:1.以传统烃类捕收剂煤油对实验煤样进行单元浮选实验。研究捕收剂用量、起泡剂用量和矿浆浓度对浮选的影响,确定最佳浮选工艺条件为:煤油用量为12kg/t,起泡剂用量为500g/t,矿浆浓度为80g/L。2.分别用脂肪醇聚氧乙烯醚(AEO9)、壬基酚聚氧乙烯醚(NP10)和油酸二乙醇酰胺(ODEA)三种非离子表面活性剂与煤油按照不同配比复配,制得复配型捕收剂,然后进行浮选实验。结果表明,经过复配后,要达到相似的浮选效果,所耗用的复配型捕收剂用量仅为单独使用煤油的1/3。在相同配比下,捕收剂用量增大,精煤产率、尾煤灰分和可燃体回收率均增大,最终确定复配型捕收剂中表面活性剂与煤油的最佳配比为1:10。3.分别用脂肪醇聚氧乙烯醚(AEO9)、壬基酚聚氧乙烯醚(NP10)和油酸二乙醇酰胺(ODEA)三种非离子表面活性剂、水和煤油按照一定比例制得稳定的乳化液,用乳化液对实验煤样进行浮选实验,探究其对浮选的促进作用。结果表明,乳化液做捕收剂可以更好的完善浮选指标。乳化后煤油粒度变细,在矿浆中分散更均匀,更易附着于煤粒表面,提高精煤的上浮率。AEO9和ODEA混合乳化液对煤样存在协同作用,两者混合可以使乳化液中胶束浓度增多,改善乳化液的性质,从而提高煤泥浮选的捕收性。4.采用高剪切调浆技术对煤泥进行预处理,与常规浮选进行对比,结果表明高剪切条件技术的应用对煤泥浮选具有一定的促进作用。红外光谱表明,含氧官能团和烃类基团特征峰的强度变化大小为:乳化液煤油,即乳化液与煤泥的作用强度大于煤油。
[Abstract]:With the mechanization of mining technology and the depletion of high-quality coal, a large number of high-ash fine-grained coal slime has emerged. Flotation is one of the most effective methods to deal with high-ash fine-grained coal slime. In the traditional flotation process, traditional hydrocarbon collectors carry a large number of gangue minerals while collecting coal particles, resulting in a large number of fine slime entrainment. There is a problem of poor selectivity. At the same time, because of the oxygen-containing functional groups on the surface of coal particles and poor hydrophobicity, it is difficult for traditional hydrocarbon collectors to catch coal particles, so the problem of poor collector performance will also occur. Adding a proper amount of surfactant to the collector can improve the flotation effect and realize the high efficiency separation of coal particles and gangue minerals. How to find a suitable surfactant is a difficult problem in flotation process. In view of the difficult floating characteristics of fine coal slime with high ash, polyoxyethylene ether type and alkanolamide type Nonionic surfactants were mixed with kerosene, and emulsion was formed instead of flotation process using kerosene alone as collector. To explore its promoting effect on the flotation of coal slime. In the process of experiment, taking the slime of a coal preparation plant in Shendong as the research object, through the flotation experiment, the flotation effect of different types of collectors on the coal slime was evaluated, and its influence on the flotation was investigated. In addition, the effect of different rotation speed and different pulping time on flotation was compared with the pretreatment technology of high shear pulping. Compared with conventional flotation, the influence of high shear sizing on flotation is analyzed. Then the synergistic mechanism of emulsified collector was studied by infrared spectroscopy. The contents of the experiment and the conclusions obtained are as follows: 1. The unit flotation experiment of experimental coal samples was carried out with the traditional hydrocarbon collector kerosene. The effects of collector dosage, frother dosage and slurry concentration on flotation were studied. The optimum flotation conditions were determined as follows: the dosage of kerosene is 12 kg / t, the amount of foaming agent is 500 g / t, and the concentration of slurry is 80 g / L. Using fatty alcohol polyoxyethylene ether (AEO9), nonylphenol polyoxyethylene ether (NP10) and oleic acid diethanolamide (ODEA) as Nonionic surfactants and kerosene in different proportion, the complex collector was prepared, and then flotation experiment was carried out. The results show that in order to achieve similar flotation effect after blending, the amount of compound collector consumed is only 1 / 3 of kerosene used alone. Under the same ratio, the yield of refined coal, ash content and combustible recovery of tail coal increased with the increase of collector dosage. Finally, the optimum ratio of surfactant and kerosene was determined to be 1 / 10. 3. Stable emulsions were prepared by using fatty alcohol polyoxyethylene ether (AEO9), nonylphenol polyoxyethylene ether (NP10) and oleic acid diethanolamide (ODEA) as Nonionic surfactants, water and kerosene in a certain proportion. The experiment of flotation of experimental coal samples with emulsion was carried out to explore its promoting effect on flotation. The results show that the flotation index can be improved better by using emulsion as collector. After emulsified kerosene particle size became finer, dispersed more evenly in slurry, more easily attached to the surface of coal particle, and increased the floating rate of fine coal. AEO _ 9 and ODEA mixed emulsion had synergistic effect on coal sample, and the micelle concentration in emulsion could be increased by the mixture of AEO _ 9 and AEO _ 9. Improve the properties of emulsion so as to improve the collector of slime flotation. 4. The pretreatment of coal slime by high shear mixing technology is compared with that of conventional flotation. The results show that the application of high shear condition technology can promote the flotation of coal slime to a certain extent. The infrared spectra show that the intensity changes of the characteristic peaks of oxygen-containing functional groups and hydrocarbon groups are as follows: emulsified kerosene, that is, the interaction strength between emulsion and kerosene is greater than that of kerosene.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD94;TD923

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