官能团对起泡性能和泡沫稳定性影响的研究

浮选是分离微细物料的重要方法,起泡剂类型和泡沫稳定性显著影响浮选效果。本文选取醇类(MIBC)、酯类(DEP)和醚醇类(DGBE)三种起泡剂,通过实验研究官能团对起泡性能和泡沫稳定性的影响。实验用Foamscan测定起泡剂溶液的起泡性能和泡沫稳定性,用Tracker流变仪测定表面张力和气液界面黏弹模量。研究结果表明：起泡速率随表面张力的减小呈线性增大,当气液界面吸附起泡剂达到饱和时起泡速率最大,其中MIBC的起泡速率最高,DGBE最小;起泡剂浓度为临界质量分数时,起泡能力最大,MIBC、DEP和DGBE的临界质量分数分别为1.1%、0.4%和0.8%;气泡的大小随溶液表面张力减小而减小,气泡平均尺寸由大至小顺序为：DGBE>DEP>MIBC;在泡沫稳定性方面,醚醇类起泡剂最强,醇类起泡剂最差,同时MIBC、DEP和DGBE质量分数分别为0.4%、0.5%和0.8%时,起泡剂生成的泡沫最稳定。

The influence of functional groups in frothers on foaming performance and foam stability

Flotation is an important method for the separation of fine materials.The type of frothers and the stability of the foam significantly affect flotation performance.In this paper, three foaming agents of alcohols (MIBC), esters (DEP) and ether alcohols (DGBE) are selected to investigate the effect of functional groups in frothers on foaming performance and foam stability.Foamscan was used in the experiment to determine the foaming performance and foam stability of the frothers, and the Tracker rheometer was used to determine surface tension and the viscoelastic modulus of the air-liquid interface.Results show that the foaming rate increases linearly with the decrease of surface tension.It reaches its peak/the maximum when the gas-liquid interface adsorbs the foaming agent to saturation, and when the adsorption of the foaming agent on the gas-liquid interface reaches saturation.The foaming rate of MIBC reaches its peak/the maximum and that of DGBE its trough/the minumum.When the concentration of the frother reaches the critical mass fraction, the foaming ability reaches its peak/the maximum, and the critical mass fractions of MIBC, DEP and DGBE are 1.1 %, 0.4 % and 0.8 %.The size of the bubbles decreases with the decrease of the surface tension of the solution, and the order of the average bubble size from large to small is: DGBE>DEP>MIBC.The ether alcohol frothers have the strongest foam stability, while the alcohol frothers have the worst foam stability.The foam is the most stable.when the mass fractions of MIBC, DEP and DGBE are 0.4 %, 0.5 % and 0.8 %.