Flotation Performance And Mechanism Of Anion-cationic Combined Collector On Tungsten Minerals

Tungsten ore is an important strategic mineral resource in China and plays an important role in the world.However,there are many special attribute in tungsten resources such as low grade and fine particle size,and it is difficult to separate tungsten minerals from gangue minerals by flotation with traditional collectors.In this paper,wolframite,scheelite and their associated gangue minerals quartz,fluorite and calcite were selected as the research objects.Through the pure mineral flotation test,the effects of single and combined use of sodium oleate（Na OL）,benzohydroxamic acid（BHA）,dodecylamine（DDA）and cocamine（ACO）on the floatability of five minerals were systematically studied.The experimental results of artificial mixed ore show that,the flotation separation of tungsten minerals and gangue minerals can be achieved better with the BHA-ACO combined collector with the BHA:ACO mass concentration ratio of 1:1.By means of adsorption capacity test,contact angle test,infrared spectrum analysis and XPS photoelectron spectroscopy test,the mechanism of interaction between the BHA-ACO combined collector and minerals was studied.This study has certain theoretical significance and guiding value on solving the flotation separation of large number of low-grade fine tungsten mines in our country and improving the development and utilization of tungsten resources.The findings and conclusions are as follows:1.The study of pure mineral flotation showed that the flotation separation of tungsten minerals and gangue minerals could not be effectively achieved by using Na OL,BHA,DDA and ACO alone or in combination;However,when the pulp pH was 10,the recovery of wolframite was 90.68%and 88.62%with 100mg/L the BHA-ACO combined collector.The best reagent mass concentration ratio of the combined collector flotation is BHA:ACO=1:1.2.The flotation study of artificial mixed ore showed that the BHA-ACO combined collector could obtain wolframite coarse concentrate with WO₃ grade of 66.15%and WO3 recovery of 89.85%,and scheelite coarse concentrate with WO₃ grade of 69.36%and WO₃ recovery of 82.38%.The above industrial indexes show that the combined collector is an efficient collector of tungsten minerals,and can better realize the flotation separation of wolframite,scheelite and three gangue minerals.3.Studies on the selective action mechanism of the BHA-ACO combined collector on the surface of tungsten minerals and gangue minerals show that the chemical adsorption of the BHA-ACO combined collector on the surface of wolframite and scheelite occurs.The adsorption capacity test results showed that ACO in the BHA-ACO combined collector could selectively increase the adsorption capacity of BHA on wolframite and scheelite surface.Contact angle test results show that the BHA-ACO combined collector can selectively increase the contact angle of wolframite and scheelite surface.The results of infrared spectrum analysis show that the chemical adsorption of BHA on wolframite and scheelite surface is obvious,but the chemical adsorption of quartz,fluorite and calcite surface is weak or does not exist.XPS analysis showed that the chemisorption mechanism of the BHA-ACO combined collector with wolframite and scheelite was that the-CONHOH group of BHA in the combined collector formed Fe（BHA）₂ with the Fe site on wolframite surface,and Ca（BHA）₂ with the Ca site on the scheelite surface.