超声乳化与化学改性协同作用对起泡剂性能的影响

发布时间：2018-03-25 09:32

  本文选题：浮选　切入点：起泡剂　出处：《太原理工大学》2015年硕士论文

【摘要】：在煤炭浮选中，起泡剂的性能不仅影响气泡的质量和数量，也影响着煤炭颗粒之间的碰撞行为，且能促进泡沫层中粘附在气泡上的不同疏水性的矿粒分离。目前，选煤厂现场常用的起泡剂有仲辛醇、杂醇、2#油等，这些起泡剂，尤其是天然起泡剂，来源有限，且由于起泡性能差、泡沫稳定性差等原因，浮选效果不甚理想。本文通过超声乳化、化学改性、化学改性与超声乳化联合作用等试验方法，用溶解度、表面张力、浮选效果等指标进行表征，对实验室常用起泡剂仲辛醇及现场常用的杂醇类起泡剂进行改性，以提高仲辛醇等起泡剂的利用率和起泡性能。结果表明，，经过超声乳化后，起泡剂利用率提高，浮选效率提高；经化学改性得到的新药剂也大大提高了浮选效率；且超声乳化与化学反应协同作用改性的起泡剂的浮选效率高于超声乳化、化学反应单独作用的浮选效率。得到以下结论： 1、通过对试验煤样的工业分析、XRD分析及粒度组成分析可知，晋城无烟煤样中含有高岭土，导致煤粒泥化严重，不利于浮选；煤样中小于0.045mm的极细粒级含量较多，约30%，且灰分很高，为33.72%；经浮选得其可燃体回收率为61%，晋城无烟煤为中等可浮性煤。 2、在25kHz的超声功率下，对所选起泡剂进行乳化处理，得到仲辛醇、A、B三种起泡剂各自的最优乳化条件，即仲辛醇：起泡剂与水比例1:5，乳化时间8min，超声强度为100%，变幅杆长度为8mm；起泡剂A：起泡剂与水比例1:2，乳化时间4min，超声强度为100%，变幅杆长度为8mm；起泡剂B：起泡剂与水比例1:1，乳化时间4min，超声强度为100%，变幅杆长度为8mm。对乳化后的起泡剂进行稳定性探究，得知：仲辛醇等在合适的条件下均能乳化，但乳化效果不稳定；加入稳定剂后，各乳液能保持稳定。 3、对起泡剂进行酯化、酸化改性试验，得到结论如下：用邻苯二甲酸酐酯化的方法改性仲辛醇得到的起泡剂浮选精煤产率提高了8%，效果较明显，但起泡剂A、B经酯化后浮选性能没有改变，说明这种改性方法对仲辛醇是有效的；用硫酸酸化改性仲辛醇、A、B浮选的精煤产率分别提高了10%，9%，13%，效果明显，说明这种改性方法是有效的；用磷酸酸化的方法改性仲辛醇、A、B得到到的对应起泡剂浮选的精煤产率分别提高了5%，6%，7%，效果较明显，说明这种改性方法是有效的；仲辛醇、A、B的最佳酯化条件是：酯化时间采用5h，催化剂选择硼酸，溶剂选择环己烷，醇与酸酐比例1:1.6，酯化温度100℃。 4、对起泡剂进行化学改性与超声乳化联合作用改性试验，得到结论如下：对仲辛醇、A、B单独进行超声乳化或化学改性，均能提高其浮选产率；对仲辛醇、A、B联合进行超声乳化和化学改性，其浮选产率比超声乳化或化学改性单独作用效果好。
[Abstract]:In coal flotation, the properties of foaming agents not only affect the quality and quantity of bubbles, but also the collision behavior of coal particles, and can promote the separation of different hydrophobic particles adhered to bubbles in the foam layer. The commonly used foaming agents in coal preparation plants are secondary octanol, hetero alcohol oil, etc. These foaming agents, especially natural foaming agents, have limited sources, and because of poor foaming performance and poor foam stability, The flotation effect is not ideal. In this paper, the solubility, surface tension and flotation effect are characterized by ultrasonic emulsification, chemical modification, chemical modification and phacoemulsification combined with phacoemulsification. In order to improve the efficiency and foaming performance of common foaming agents such as para-octanol in laboratory and hetero alcohol foaming agent in field, the results show that the utilization ratio of foaming agent is increased after phacoemulsification. The flotation efficiency is improved, the flotation efficiency is greatly improved by chemical modification, and the floatation efficiency of the foaming agent modified by phacoemulsification and chemical reaction is higher than that of phacoemulsification. The flotation efficiency of chemical reaction alone. The following conclusions are obtained:. 1. According to the industrial analysis and particle size composition analysis of the coal sample, it can be seen that there is kaolin in the coal sample of Jincheng anthracite, which leads to the serious slime of coal particles, which is not conducive to flotation, and the content of very fine grain in the coal sample is more than that of 0.045mm. About 300.The ash content is very high, 33.72.The combustible recovery rate is 61and the Jincheng anthracite is medium floatable coal by floatation. 2. Under the ultrasonic power of 25kHz, the optimum emulsifying conditions of the three foaming agents were obtained by emulsifying the selected foaming agents. That is, the ratio of foaming agent to water is 1: 5, emulsifying time is 8 minutes, ultrasonic intensity is 100 and the length of horn is 8mm; foaming agent A: the ratio of foaming agent to water is 1: 2, emulsifying time is 4 minutes, ultrasonic intensity is 100 and the length of horn is 8 mm; foaming agent B: foaming agent and water. The ratio is 1: 1, emulsifying time is 4 minutes, ultrasonic intensity is 100, and the length of amplitude lever is 8 mm. the stability of foaming agent after emulsification is studied. The results show that the emulsion can be emulsified under suitable conditions, but the emulsifying effect is not stable, and the emulsion can be kept stable after the addition of stabilizer. 3. The experiments of esterification and acidification of foaming agent were carried out, and the conclusions were as follows: the yield of fine coal flotation by modified secondary octanol by phthalic anhydride was increased by 8%, and the effect was obvious. However, the flotation performance of foaming agent Anb has not changed after esterification, which shows that the modified method is effective for secondary octanol, and the refined coal yield by sulfuric acid acidizing modified para-octanol Anb floatation has been increased by 10% and 13% respectively, which shows that the modified method is effective. The effect of phosphoric acid acidizing method on the yield of purified coal from the floatation of the corresponding foaming agent was increased by 5% and 6% respectively, which shows that the modified method is effective. The optimum esterification conditions are as follows: the esterification time is 5 h, the catalyst is boric acid, the solvent is cyclohexane, the ratio of alcohol to anhydride is 1: 1.6, and the esterification temperature is 100 鈩

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