The Relationship Between The Flotation Behavior Of Kaolinite And Its Surface Properties

Kaolinite exists in a large amount in coal slime water,which seriously affectsthe recovery of fine coal in coal slime water.Because the surface of kaolinite is charged with negative electricity and has a low hardness of only about 2.8 mohs,it is easy to slime,which makes it difficult to recover and utilize useful components in slime water.In the process of aluminum industry smelting in China,diaspore with an aluminum silicon ratio of more than 8 is needed,and kaolinite is the main gangu.How to effectively separate kaolinite from minerals is a difficult problem.In this paper,kaolinite is taken as the research object to study the influence of the change of surface properties on the flotation behavior of minerals in different flotation systems,so as to establish the relationship between the crystal structure,surface properties and flotation behavior of minerals,and through solution chemical calculation,infrared spectroscopy and XPS analysis.Detection and other research methods to explore the way of action of reagents and ions on minerals.Through the calculation of crystal structure,the unique crystal structure of kaolinite determines the condition and strength of its adsorption with the agent.In the slurry solution,Al-OH and Si-OH on the end face of kaolinite will change with the change of pH value.In the bottom of kaolinite?0 0 1?and?0 0-1?,due to the isomorphism and lattice substitution,Al³⁺and Si⁴⁺will be replaced by Mg²⁺,Fe²⁺,and Al³⁺,and the order of strength and weakness of Mn+xn bond of metal ions is obtained by calculation:Si-O>Al-O>Fe-O>Ca-O.In the single mineral flotation system,the optimal pH of anionic collector sodium oleate for kaolinite flotation is in the alkaline range,while the optimal pH of cationic collector for kaolinite is in the acid range,and the effect of dodecylamine on kaolinite is better than that of sodium oleate;the particle size has a great influence on kaolinite flotation,and the recovery of kaolinite fine-grained flotation can be more than 95%under the appropriate conditions.After choosing the cationic collector dodecylamine,sodium hydroxide and dilute hydrochloric acid as pH adjusters,the effect of metal ions on the flotation of kaolinite with different particle sizes was studied.The results showed that trivalent ions promoted the flotation of kaolinite The effect is generally stronger than that of divalent metal ions,but the promotion of metal ions is also closely related to environmental factors,such as the pH of the pulp,the type and amount of flotation reagents,and two inhibitors selected in this experiment.Inorganic inhibitor sodium hexametaphosphate and organic inhibitor sodium lignosulfonate,these two inhibitors also have an inhibitory effect under acidic conditions,kaolinite flotation effect is weakened,but in alkaline or neutral environment,the two All kinds of inhibitors can improve the recovery rate of kaolinite flotation.The mechanism study shows that both sodium oleate and dodecylamine are chemically adsorbed on the mineral surface,the characteristic peaks of the reagents can be seen in the infrared spectrum,and the binding energies of Al and Si can be seen to shift in XPS.No obvious new peaks were found in sodium hexametaphosphate and sodium lignosulfonate.It is speculated that they can affect the test mainly by changing the flotation environment of kaolinite to affect the flotation behavior of kaolinite.