Study On Flotation Behavior And Mechanism Of Kyanite

Kyanite is widely used,and the flotation is one of the main beneficiation methods in preparation for kyanite concentrates.This paper will focus on the effects of metal ions and regulators on the floatability of kyanite,to find out how to use（or eliminate）the effects of metal ions and regulators on the floatability of kyanite.The research includes the flotation conditions of single mineral and the action mechanism of pharmacy and kyanite surface under the flotation system of sodium dodecyl sulfonate and dodecyl sodium.Under the system of sodium dodecyl sulfonate:Two kinds of monovalent ions Na⁺and K⁺had no effect on the floatability of kyanite;Two kinds of divalent ions Ca²⁺and Mg²⁺showed inhibitory effects on the formation of Ca²⁺and Mg²⁺components,and Mg²⁺ion showed the weaker inhibitory effect than that of Ca²⁺ion.Two kinds of trivalent ions Fe³⁺and Al³⁺showed activation effects on the formation of Fe（OH）₂⁺,FeOH²⁺,Fe（OH）_3（s）and Al（OH）₂⁺,AlOH²⁺,Al（OH）_3（s）components,and Fe³⁺ion showed the weaker activation effect than that of Al³⁺ion;Sodium hexametaphosphate inhibited the kyanite to float,the inhibitory effect of H₂PO₄component was more remarkable than H₃PO₄;Starch inhibited the kyanite to float and the inhibitory effect of starch in the strong acid medium was more remarkable;Citric acid inhibited the kyanite to float,the inhibitory effect of C₆H₇O₇^-and C₆H₆O₇^2-components were more remarkable than C₆H₈O₇ component.Under the system of dodecyl sodium:Before the addition of metal ions,the PZC of kyanite was 6.5;the PZC of kyanite increased to 7.3 after the addition of Ca²⁺ion,the PZC increased to 7.1 after the addition of Mg²⁺ion,the PZC increased to 7.5after the addition of Al³⁺ion,the PZC increased to 7.8 after the addition of Fe³⁺ion,the increase rate of PZC was Fe³⁺>Al³⁺>Ca²⁺>Mg²⁺,and this was consistent with their ability to inhibit kyanite;When 3≤pH≤7,calcium ion and magnesium ion mainly existed in the form of Ca²⁺and Mg²⁺,and the concentration of RNH₃⁺in the interfacial layer was less than that of RNH₃⁺in the liquid phase,under these conditions two ions had strong inhibitory effect on kyanite.When 7<pH≤9,the components of CaOH⁺and MgOH⁺began to form and increase gradually,but at this time the activation component concentration was low and the activation was not strong,and the concentration of RNH₃⁺in the interfacial layer was greater than the concentration of RNH₃⁺in the liquid phase,the inhibition of the two ions gradually weakened;When 3≤pH≤9 in the range of whole flotation slurry pH,the aluminum ion was mainly in the form of Al³⁺and Al（OH）_3（s）components,iron ion was mainly in the form of Fe（OH）_3（s）,these three components could adsorb on the surface of kyanite and weakened the electrostatic attraction force of dodecylamine,and when3≤pH<8,the concentration of RNH₃⁺in the interfacial layer was less than that of RNH₃⁺in the liquid phase,two ions had strong inhibitory effects on kyanite.When8≤pH≤9,the concentration of RNH₃⁺in the interfacial layer was greater than that of RNH₃⁺in the liquid phase,the inhibition of the two ions gradually weakened;Sodium hexametaphosphate inhibited the kyanite to float,the inhibitory effect of H₃PO₄ and H₂PO₄^-components were more remarkable than HPO₄^2-and PO₄^3-components;Starch inhibited the kyanite to float and the inhibitory effect of starch in the acid medium was more remarkable;Citric acid showed activation effect on kyanite flotation,the activation effects of C₆H₇O₇^-and C₆H₆O₇^2-components were more remarkable than C₆H₅O₇^3-component.The results of FTIR test showed that sodium dodecyl sulfonate,dodecylamine,sodium hexametaphosphate and citric acid were adsorbed on the surface of kyanite,and starch may have occurred physical adsorption.