Effect Of Metal Ions On Dispersion And Aggregation Behavior Of Fine Wolframite,Chlorite And Quartz

Due to the influence of high surface solubility of fine mineral,production water,crushing and grinding technology,a large number of unavoidable metal ions are often introduced.These inevitable metal ions adsorption on the mineral surface will change the physical and chemical properties of the mineral surface,affect the dispersion and aggregation behavior of mineral particles,and then affect the flotation of minerals.In this paper,micro-fine wolframite,chlorite and quartz were selected as the research objects,and different metal ions were selected to systematically study the influence of the valence state,concentration and p H value of metal ions on the dispersion and coagulation behavior of minerals.Through Zeta potential test,DLVO theory calculation,adsorption capacity experiment,XPS test and component analysis of metal ion hydrolysis,the mechanism of metal ion’s influence on mineral dispersion and agglomeration behavior was clarified.The experiment on the influence of metal ions on the dispersion and coagulation of minerals shows that the valence state of metal ions has a great influence on the dispersion and coagulation behavior of the three minerals.The monovalent metal ions potassium and sodium have little effect on the dispersion and aggregation behavior of the three minerals.The addition of divalent and trivalent metal ions can significantly damage the dispersion stability of the three minerals in a certain p H range,and with the increase of the concentration of metal ions,the phenomenon of mineral agglomeration becomes more obvious.The results of FBRM and optical microscope showed that the compact aggregates of wolframite and chlorite could be observed under optical microscope in the presence of metal ions.Therefore,stirring has little effect on the dispersion and aggregation behavior of wolframite and chlorite,but it has obvious effect on the agglomerates of quartz particles.Flotation experiments show that the agglomeration of minerals with sodium oleate as collector can significantly improve the flotation rate and recovery of micro-fine minerals.The results of Zeta potential measurement showed that the addition of Pb²⁺,Mn²⁺,Fe²⁺and Al³⁺had a great effect on the surface potential of the three minerals,and the Zeta potential on the surface of the minerals all showed an overall positive shift.DLVO theory calculation well explain the three types of dispersion condensing behavior of minerals in deionized water system,but after introduction of metal ions,in a certain p H range can be more significantly lower barrier between mineral grains,but has not completely eliminate the barrier between mineral grains,the addition of metal ions,make mineral the interparticle forces become more complex,therefore cannot well explain metal ions join results in significant condensation phenomenon between mineral grains.The experimental results of metal ions adsorption on mineral surface show that the greater the amount of metal ions adsorption on mineral surface,the more obvious the mineral agglomeration.The hydrolytic component calculation and XPS analysis of metal ions further revealed that the positively charged hydroxyl complexes and their hydroxide precipitation were the main components promoting the agglomeration of the three minerals,and the positively charged hydroxyl complexes mainly caused the agglomeration of the three minerals through electrostatic bridging.The hydroxide precipitation causes the agglomeration of the three minerals by precipitation net.