Study On Minerals Particles Containing Calcium And Bubble Interaction

In this paper, electro-flotation method is applied to study flotation performances of scheelite, calcite and fluorite particles with three different size fractions in a modified hallimond tube. The effects of gas holdup, bubble size and particle size on the interaction between bubble and three minerals containing calcium with three size fractions at various collector concentrations were investigated. Furthermore, the paper is studying on changes in bubble size and the distribution under the different electrolysis conditions, and form of bubble-particle by using high speed video camera. A bubble-particle interaction model is also established in the paper.The study by high speed CCD finds that there is evidence for a decrease in bubble size, and the median bubble size is smaller and the distribution more even in the presence of collector. Bubble clusters occur only when solid particles are present. The collector concentration has a strong effect on the size of the clusters. For different minerals, the influence is not the same. In addition, there is a remarkable correspondence between the clusters diameter and the shape factor. The size of the bubble clusters increases as the solids concentration increases.It is found that gas holdup and bubble size have pronounced effect on the recoveries of minerals. Gas holdup increases obviously with the increase of current intensity, while bubble size decreases. The flotation recoveries of minerals with three size fractions increase with the increasing of slurry gas holdup in the experiments. For the different size minerals, their flotation behavior is diverse in different sizes of bubbles. It is also found that calcite had good flotation behavior, but flotation recoveries of scheelite and fluorite declined obviously at low collector concentration.Through the model establishment, process of bubble-particle interaction was divided into three stages. (1) Capture of individual particles by individual 'clean' bubbles; (2) Capture of further particles by the particular bubble; (3) Collision of two or three loaded bubbles leads to combining together to form clusters.