煤用起泡剂乳液稳定性研究与形成机理分析

Stability study and formation mechanism analysis of coal frother emulsion

通过对起泡剂乳液乳滴粒径变化规律的探索,研究了乳化剂种类、用量、油水质量比以及剪切速率等因素对乳液稳定性的影响,并探讨了起泡剂乳液的形成机理。研究结果表明,以山梨醇酐油酸酯(Sapn80)与油酸钠(SO)复配的亲水亲油平衡值(HLB)为15的乳化剂,在乳化剂用量为3.5w%、油水质量比为3∶7、剪切强度为3000r/min时制备的起泡剂乳液粒径小且分布集中,乳液稳定性达到最佳,此时乳滴平均粒径(D_(50))为0.21μm、跨距((D_(90)-D_(10))/D_(50))为0.29。油水两相在剪切作用力下破碎成小液滴并呈分散状态,乳化剂通过降低体系油水界面张力,帮助形成小粒径液滴并吸附在油水界面形成界面膜阻止液滴聚并,维持液滴的分散状态,使乳液稳定存在。

The effect of emulsifier type and amount, oil-water mass ratio and shear rate and other factors on emulsion stabili ty had been studied by analyzing the variation rule of the emulsion droplet size of frother, and formation mechanism of the frother emulsion was discussed. The research results showed that the best emulsion stability with small particle size and concentrated dis- tribution occurred under the conditions that the mixture of sorbitan monooleate （Sapn 80） and sodium oleate （SO） was used as an emulsifier （HLB value of 1,5） with usage amount of 3.5 w%, the shear rate was 3000 r/min and oil/water mass ratio was 3 ： 7. In such conditions the emulsion droplets had average particle diameter （D50） of 0.21 〉m and span length （（D90-D10）/D50 ） of 0.29. Water-oil phase was broken into small droplets by shear forces and formed dispersed state. Emulsifier was conducive to the formation of small droplets by decreasing the surface tension of oil-water system, it also prevented colloidal particles coalescence, maintained the dispersion state of the colloidal particles and stabilized the emulsion by adsorbing on the oil-water interface and forming oil-water interracial film.