矿浆受迫高频振动的空化微泡激发机制研究

Microbubble flotation is an effective method to recover minerals with fine size. However, except for flotation column and jet flotation machine, it is hard for regular flotation machine to obtain a satisfied economic benefit for fine mienrals, due to its difficulty for microbubble generation. Based on the fact that microbubble could generate through water stimulated by forced vibration of mechanical wave in high frequency, technique prototype of cavitating microbubble stimulation flotation for fine minerals was proposed. In this project, spectral analyzer will be used to determine the transmission characters of mechanical wave in the three-dimensional space of water. High speed dynamic video camera will be performed to measure the size, shape, distribution and amount of microbubble. Microbubble characters influenced by the frequency, intensity and echo of the high frequency vibration machine wave will be studied to investigate the stimulation mechanism of cavitation microbubble. Using chalcopyrite and pyrite with size under 20μm as objects, flotation test will be conducted to compare the flotation performance of cavitation microbubble and regular aeration bubble. It will be also explored that the influence of intensity and frequency of machine wave on the flotation behavior. The flotation characters of cavitation microbubble will be investigated in detail. This project will provide theoretic principal for fine mineral flotation using cavitating microbubble flotation.

微泡浮选已经成为回收微细粒级矿物的有效方法，但除浮选柱和射流浮选机外，常规浮选机由于产生微泡困难，对微细粒级矿物的回收存在效益低下的问题。本项目基于水溶液在受迫高频振动机械波的空化激发下，可以产生微泡的事实，提出微细粒级矿物空化微泡激发浮选方法技术原型。项目采用波谱仪检测振源发射的机械波，研究高频振动机械波在水溶液三维空间的传播特性；采用高速动态摄影仪对空化激发产生的微泡进行摄影，研究微泡的尺寸、形状、分布、数量等参数，同时研究高频振动机械波频率、强度、回波等参数对微泡特性的影响，探索水溶液受迫高频振动时的空化微泡激发机制。以粒度小于20微米的微细粒级黄铜矿和黄铁矿纯矿物为研究对象，通过浮选试验，比较空化激发微泡与常规充气气泡的浮选效果，考察高频振动机械波频率、强度等参数对浮选回收率指标的影响，研究空化激发微泡的浮选性能，为微细粒级矿物空化微泡激发浮选方法的应用提供理论依据。

微泡的发生装置和相应的机理研究已经成为矿物浮选的一个研究热点。本课题提出使用空化作用产生微泡，以提高矿物的浮选效率。目前空化作用在浮选中的运用大多集中于预处理阶段，对其在浮选过程中的影响尚不完善，尤其缺乏对矿物表面性质和气泡大小的影响研究。申请人通过本课题的研究，将空化作用直接作用于矿物浮选的粗选和精选阶段，阐明了高频机械波在矿浆中的能量衰减，揭示了可见微泡（毫米级）的发生和运动机制，同时运用多种表面研究的手段考察了空化作用对黄铁矿表面性质改性的作用原理。最后研究了空化作用对黄铁矿粗选、精选过程浮选动力学的影响。