Study On The Influence Mechanism Of Pretreatment On Fluorite Flotation

Fluorite is an important strategic resource in China,widely used in chemical industry,building materials,metallurgy and other fields,and the demand for high grade fluorite is increasing day by day.Pretreatment is usually carried out before fluorite flotation to improve the flotation index of fluorite.Microwave has the characteristics of selective heating,fast speed and high efficiency,which is widely used in the fields of ore dressing,metallurgy,materials and so on,especially in the aspects of crushing,leaching,roasting,drying and reduction of minerals.In this paper,with fluorite pure minerals as the research object,the effects of microwave pretreatment of pure minerals,deionized water,pulp and pulp with collector on the flotation recovery of fluorite was investigated under four ways,such as collector dosage,pH value,microwave time and power.The action mechanism of microwave on minerals flotation was analyzed by chemical calculation of sodium oleate solution,Zeta potential detection,infrared spectrum test,adsorption calculation of sodium oleate and flotation kinetics calculation.Flotation test results showed that compared with the best flotation results before microwave pretreatment,microwave pretreatment of pure minerals,deionized water and flotation of pulp with collector can improve the flotation recovery of fluorite,and the flotation recovery rate of fluorite is respectively improved 3.2 percent,4.5 percent,4.2 percent under the flotation conditions of pH value of 7 and the concentration of sodium oleate of 110mg/L;However,the flotation recovery of the pulp was obviously reduced by 1.6 percent under the flotation conditions of pH value of 8 and the concentration of sodium oleate of 120mg/L.The detection and analysis of Zeta potential and infrared spectroscopy showed that microwave pretreatment of pure minerals and deionized water increased the positiveness of the surface of fluorite,which promoted the adsorption of sodium oleate on the surface of minerals;microwave pretreatment of the slurry reduced the positiveness of the surface of fluorite,inhibits the adsorption of sodium oleate on the surface of minerals,and its adsorption methods included both physical adsorption and chemical adsorption.The adsorption capacity calculation results of sodium oleate on the surface of fluorite before and after microwave pretreatment showed that the sequence of sodium oleate adsorption capacity on fluorite surface was from top to bottom as microwave pretreatment of deionized water > microwave pretreatment of pulp with collector >microwave pretreatment of pure mineral > without microwave pretreatment,which was consistent with the law of fluorite flotation test.The flotation kinetics analysis results indicated that the fluorite flotation conformed to the first-order kinetics model before and after microwave pretreatment.Microwave pretreatment of fluorite pure minerals,deionized water and pulp with collector not only increased the flotation recovery of fluorite,but also accelerated the flotation rate,while microwave treatment of pulp decreased the flotation recovery and flotation rate of fluorite.