Study On The Mechanism Of Selective Flotation Separation Of Magnetite And Apatite

China is extremely rich in high phosphate iron ore resources.However,there is the high content of harmful phosphorus elements in iron ore,the availability of such iron ore is reduced.In the smelting process,the harmful phosphorus elements in the iron ore are removed in advance,which can avoid the"cold and brittle"phenomenon of the smelting products due to the excessive phosphorus content,and improve the quality of the smelted products.This paper is supported by the National Natural Science Foundation of China"Fe-S-P system calcium component-induced activation-sulfur-phosphorus synchronous flotation separation mechanism".Using magnetite and apatite pure minerals as the research object,this paper adopt a new collector and mixed inhibitors to conduct flotation test research.Combined with the joint characterization of multiple inspection methods,this paper conduct a mechanism study on the selective flotation separation of magnetite and apatite,and to reveal the internal laws of the flotation separation of the two.This paper will provide some basic theory and technical support for the research of iron removal and dephosphorization of high phosphorus magnetite in China.In the flotation experiment,a specific ratio of oleic acid amide and sodium dodecylbenzene sulfonate was used as a new type of apatite collector,and starch and sodium lignin sulfonate were used as a mixed inhibitor of magnetite.In the slurry p H=8～9,the ratio of oleic acid amide to sodium dodecylbenzenesulfonate is 2:1（molar ratio）,the total amount is 4×10^-4mol/L;The preferred ratio of inhibitor starch to sodium lignosulfonate is 8:1,and the total amount is 135mg/L;the recovery rate of apatite is 97.09%,and the recovery rate of magnetite is 15.9%.The synergistic effect between oleic acid amide and sodium dodecylbenzenesulfonate improves the effect of apatite flotation.In the binary artificial mixed ore,the optimal dosage of the reagent is determined by flotation of pure minerals.After a rough sweep of the flotation process,the separation of apatite and magnetite is achieved,and the dephosphorization rate is about 70%.The iron concentrate contains 0.46%phosphorus and the iron recovery rate is 83.12%.After the collector is added,the surface potential of apatite decreases significantly,and the C-H stretching vibration absorption peak is generated on the apatite surface;After the addition of inhibitors,the electrokinetic potential of the magnetite surface decreased significantly,and the-CH₂-asymmetric stretching vibration absorption peak was generated on the magnetite surface,and the Fe-O bending vibration absorption peak shifted,and the characteristic absorption peak of starch appeared.The combined characterization of electrokinetic potential and infrared spectroscopy proves that the collector is chemically adsorbed on the surface of apatite,the inhibitor and the magnetite surface have obvious adsorption,which is one of the important reasons for the selective separation of magnetite and apatite.Through the detection methods of XPS and TOF-SIMS,the adsorption type of the agent on the mineral surface was studied.X-ray photoelectron spectroscopy（XPS）results showed that after the addition of the new collector,two characteristic peaks of amine compound-NH-C=O and amino NH₃⁺appeared in the N1s fitted spectrum of the apatite surface,and the cation RNH₃⁺,the generation of hydrophobic species enhances the activity of oleic acid amide,and promotes the apatite to float up.When the inhibitor is added,the content of N1s on the surface of the magnetite decreases from 2.09%by 0.1.3%,the adsorption of the new collector on the surface of the magnetite decreases,and the concentration of oxygen atoms in Fe-OH increases by 15.18%.A large amount of hydrophilic hydroxy iron components are formed on the surface,thereby inhibiting magnetite.Time-of-flight secondary ion mass spectrometer（TOF-SIMS）results further indicate:the synergy between oleic acid amide and sodium dodecylbenzene sulfonate has been created,which enhances the adsorption of the new collector molecules on the apatite surface.The adsorption of sodium lignosulfonate and starch on the apatite surface is weak.This creates good conditions for the selective flotation separation of magnetite and apatite.