Preparation Of Fatty Acid Soap Collector And Its Flotation Performance On Fluorite

Fluorite ore is the main resource of fluoride in fluorine products and widely used in metallurgy, chemical engineering as an important nonmetal strategic resource. Froth flotation has become the most effective method for recovery of fluorite because of the problems of low grade, fine particle and complicated composition and the increasing difficulties in fluorite beneficiation. The method of saponification of fatty acid from hydrolysis was used to prepare fatty acid soap collectors of rubber seed oil, coconut oil and palm oil. The flotation performance of fatty acid soap collectors on pure fluorite and actual fluorite has been studied and the flotation mechanism has been investigated by means of adsorption capacity, Zeta-potential and FT-IR.Using rubber seed oil, coconut oil and palm oil as raw material, collectors named fatty acid soap of rubber seed oil, coconut oil and palm oil are prepared by saponification of the fatty acid from the hydrolysis of rubber seed oil, coconut oil and palm oil. The main factors influencing the hydrolysis ratio were determined, including temperature, emulsifier and its dosage, react time, dosage of catalyst and ratio of oil to water. The result shows that the hydrolysis rate of rubber seed oil, coconut oil and palm oil can be up to94.71%,96.14%and92.72%respectively.The results of flotation experiment of pure fluorite and quartz show that fatty acid soap collectors of rubber seed oil, coconut oil and palm oil have a good collective capability when flotation pH was adjusted to6-12. Besides, all three collectors exert much weaker flotation effects on quartz than fluorite. The recovery is less than17%when pH is12and the dosage of collector is100mg/L too, which also indicates that a good separation of fluorite and quartz can be achieved by these three collectors. The closed circuit flotation conditions which were obtained by roughing experiment are-200mesh of grinding of60%, sodium carbonate of1400g/t, sodium silicate of400g/t, fatty acid soap collector of rubber seed oil of500g/t. The concentrate floated by the close flow, which includes one step of roughing, one step of cleaning, one step of scavenging and six steps of cleaning after rough concentrate regrinding, has reached a grade of97.43%with recovery96.02%.The adsorption capacity of fatty acid soap collectors on the surface of fluorite tested by TOC (total organic carbon analyzer) shows that three collectors can be well adsorbed on the surface of fluorite. The adsorption capacity improves with the increase of the concentration of collectors. The adsorption capacity order of three collectors is in accordance with the result of flotation test of actual fluorite mineral. Zeta-potential test indicates the point of zero charge in water is9.0. The Zeta-potential of fluorite shift toward negative after the mutual reaction between fatty acid soap collector of rubber seed oil and fluorite that means large amounts of anion of fatty acid soap collector of rubber seed oil have been adsorbed on the surface of fluorite. Determination of the differences among fatty acid soap collector, fluorite and the fluorite which adsorbed collectors by FT-IR indicates chemical adsorption mainly takes place when pH of pulp is alkaline.