Study On The Flotation Separation Between Fluorite And Phlogopite

Fluorite has become more and more important and had increasingly broad application in the areas of industry and daily life. The demand for fluorite has been greatly increased with the rapid development in these sectors of industry in China. The fluorite was successfully separated from the gangue mineral phlogopite and the low grade beryllium ore concentrate was comprehensively recycled on the basis of the process mineralogy and pure minerals tests.Pure minerals flotation tests and flotation separation of artificially mixed minerals have been carried on for the flotation test of fluorite and phlogopite in order to reveal the flotation performance of these two minerals. The flotation performance and mechanism of collectors, metal ions and modifiers on fluorite and phlogopite have been discussed by using crystal structure analysis, solution chemistry analysis and various measurements techniques.The techniques used include Zeta potential determinations on the surface of these two minerals, infrared spectroscopy and so on.The results of pure mineral test indicate that fluorite was collected well by sodium oleate while phlogopite was hardly floated in the neutral and weak alkaline pulps; that fluorite was depressed while phlogopite was activated due to the presence of Fe³⁺and Al³⁺in the pulp; and that the detrimental effect of the metallic ions on separation between fluorite and phlogopite was eliminated by using sodium carbonate and sodium sulfide as regulators. When the dosages of NaS2and sodium oleate were2.0×10^-3mol/L and3.0X10^-5mol/L respectively, effective separation of fluorite and phlogopite was achieved at the pH value of10.0, and under these conditions the flotation separation of artificially mixed minerals were carried out quite well.The results of mechanism study indicate that in pH range of7-11, the surface potential of fluorite and phlogopite are both negative; that the acid-soap（RCOOHRCOO^-） and oleate（RCOO^-） of the collector are presumably the key roles respectively for fluorite and phlogopite by the solution chemistry analysis of sodium oleate. Sodium oleate reacts on surface of fluorite and phlogopite by adsorption. Both metal ions Fe³⁺and A1³⁺react well on the surface of fluorite and phlogopite. Na2S react well on the surface of fluorite and phlogopite, which are effected by Fe³⁺and A1³⁺. When the pH value is in the vicinity of10, potential difference between the two kinds of mineral is maximum. Infrared spectroscopic analysis shows that sodium oleate at the surface of fluorite is chemisorption; that it is physisorption and weakly chemisorption at the surface of phlogopite; but when it is effected by metal ions, it will become to chemisorption; and it will be chemisorption at the surface of phlogopite when effected by metal ions and sodium sulfide.In the real ore tests, the process mineralogy of beryllium-containing fluorite ore was studied. After the flowsheet of a rougher and five cleaning flotation, fluorite concentrate with the content of CaF₂91.27%was obtained and meanwhile a concentrate of low grade beryllium was also achieved as a by-product.