聚二甲基硅氧烷对煤泥浮选泡沫的强制消泡研究  

Compulsory defoaming of coal flotation froth by polydimethylsiloxane

作　　者：赵辉[1] 崔广文[2] ZHAO Hui;CUI Guangwen(Shaanxi Energy Institute,Xianyang 712000,China;College of Chemical and Environmental Engineering,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]陕西能源职业技术学院,陕西咸阳712000 [2]山东科技大学化学与环境工程学院,山东青岛266590

出　　处：《洁净煤技术》2021年第6期212-217,共6页Clean Coal Technology

基　　金：中国博士后科学基金面上资助项目(2020M630658)。

摘　　要：浮选精煤泡沫过于稳定是造成选煤厂浮选精矿桶容积不足和浮选精煤脱水效率低的重要原因,向浮选精煤泡沫中添加消泡剂是一种有效的化学消泡方法。将聚二甲基硅氧烷作为消泡剂用于煤泥浮选泡沫,通过测量三相泡沫稳定性、矿浆黏度、溶液表面张力等方法研究了聚二甲基硅氧烷在不同水质硬度条件下对煤泥浮选泡沫的消泡效果。三相泡沫稳定性测试结果表明,随着消泡剂用量的升高(0~0.5 g/L),三相泡沫稳定性先降低而后略有升高,并且在水质硬度较低的情况下消泡效果更加显著。矿浆黏度测试结果表明,有机硅消泡剂可大幅降低矿浆的黏度,同样在低水质硬度的条件下效果更显著。表面张力测试结果表明,消泡剂单独存在时,具有与起泡剂类似的作用,会降低溶液的表面张力,但消泡剂和起泡剂共同存在时,消泡剂能够提高溶液的表面张力,从而促进气泡兼并和破裂,降低泡沫稳定性。聚二甲基硅氧烷可以作为煤泥浮选泡沫的消泡剂,可在低用量的情况下(0.1 g/L)使浮选精煤泡沫快速消泡,从而提高浮选精煤的脱水效率。The excessively stabilized coal flotation froth is the main reason of the insufficient volume of the flotation clean coal bucket and the low efficiency of clean coal dewatering.It is a useful solution to add defoamer in coal flotation froth as a chemical defoamation method.In this work,polydimethylsiloxane was used as a demoamer in coal flotation froth.The defoamation performance was evaluated via the measurements of three-phase froth stability,pulp viscosity,and solution surface tension under different water hardness.The three-phase froth stability results show that the froth stability first decreases and then increases with the increase of demoamer dosage from 0 to 0.5 g/L,and the defoamation effect is more significant at low water hardness.The pulp viscosity results show that polydimethylsiloxane defoamer can significantly decrease pulp viscosity and again the variation is more profound at low water hardness.The surface tension results indicate that defoamer can decrease the solution surface tension just like frother when it is used solely,but it can increase solution surface tension when frother is present.As a result,the bubble coalescence and bursting can promoted and the froth can destabilized.The work shows that polydimethylsiloxane can work as the defoamer of coal flotation froth,and it can destabilize the flotation froth quickly and improve clean coal dewatering efficiency at low dosage(0.1 g/L).

关 键 词：聚二甲基硅氧烷 消泡剂 煤泥 浮选 泡沫 

分 类 号：TD923[矿业工程—选矿]