This paper investigates one aspect of surface air nucleation in froth flotation, namely the impact of frother-type surfactants like Methyl isobutyl carbinol (MIBC). During this study, tap water was pressurized in an autoclave to produce air-oversaturated water for air nucleation precondition in flotation. Various experiments were carried out with graphite particles to investigate the influences of gas nucleation and MIBC on flotation: micro-flotation, single bubble collision experiments in hydrodynamic conditions and pick-up experiments in static conditions. In addition, microscopic observations were combined with agglomeration analysis to clarify the effects of the frother MIBC on the air nucleation and agglomerate formation. The experimental results show the combination of MIBC and air nucleation can significantly increase the graphite recovery compared to using air-oversaturated water or normal tap water with MIBC alone, respectively. The analysis indicates that MIBC can improve the air nucleation probability on graphite surfaces by enhancing the stability of the air nuclei to form more microbubbles on the surface. Meanwhile, the surface microbubbles can collide with other particles forming coarser aggregates, improving their collision probability and with this increasing the recovery of fine particles. Furthermore, the results show that MIBC can reduce the detachment of particles from the surface of nucleation bubbles, leading to an increase in particle load of the bubble-particle aggregates in hydrodynamic conditions, improving the graphite recovery significantly.

本文研究了泡沫浮选中表面空气成核的一个方面，即甲基异丁基甲醇 (MIBC) 等起泡型表面活性剂的影响。在这项研究中，自来水在高压釜中加压以产生空气过饱和水，用于浮选中的空气成核前提。用石墨颗粒进行了各种实验来研究气体成核和 MIBC 对浮选的影响：微浮选、流体动力学条件下的单气泡碰撞实验和静态条件下的拾取实验。此外，将微观观察与团聚分析相结合，阐明了起泡剂 MIBC 对空气成核和团聚体形成的影响。实验结果表明，与单独使用空气过饱和水或普通自来水与单独使用 MIBC 相比，MIBC 和空气成核的组合可以显着提高石墨回收率。分析表明，MIBC可以通过增强空气核的稳定性在石墨表面形成更多的微泡来提高空气在石墨表面的成核概率。同时，表面微泡可以与其他颗粒碰撞形成更粗的聚集体，提高它们的碰撞概率，从而增加细颗粒的回收率。此外，结果表明，MIBC可以减少颗粒从形核气泡表面的脱离，导致在流体动力学条件下气泡-颗粒聚集体的颗粒负荷增加，从而显着提高石墨回收率。