Experimental Study And Mechanism Discussion Of Feldspar Beneficiation In Yichun, Jiangxi

Feldspar is widely distributed in the earth’s crust.As a rock forming mineral with important industrial value,it is widely used in glass,ceramics,refractories and other industries.The better its quality is,the higher its application value is.In natu re,feldspar is associated with quartz,mica,amphibole and other silicate minerals.Because of the similar structure of feldspar and quartz,the separation of feldspar and quartz is the key to improve the quality of feldspar minerals.At present,the flot ation separation of feldspar and quartz is usually used in industrial field.The flotation separation of feldspar and quartz has experienced three stages:fluorinated acid method,fluorine free acid method and fluorine free acid method.Among them,fluorinated acid method is still the most advanced flotation process.Taking a feldspar sample in Jiangxi Province as the research object,this paper carried out the experimental study on flotation with fluorine and acid,and discussed the mechanism of hydrofluoric acid activating feldspar.The study on the properties of the ore sample shows that the ore contains K₂O3.17%and Na₂O 4.96%;The main useful minerals are albite,potash feldspar and muscovite,and the gangue minerals are mainly quartz;There is a little intergrowth between the target minerals and quartz.The results show that it is difficult to recover feldspar effectively by fluorine-free process,and it is better to float feldspar with fluorine and acid.The mica preferential flotation process was determined,and the systematic beneficiation test was carried out,including flotation pH value test,grinding fineness test,collector condition test,flotation process structure,flotation open circuit and closed circuit test.Finally,the grade of K₂O and Na₂O in mica concentrate was 9.76%and 1.20%,and the recovery was 46.32%and 3.62%;The grade of K₂O and Na₂O in feldspar concentrate is 2.85%and 8.35%,and the recovery is49.38%and 92.52%;The contents of K₂O and Na₂O in tailings are 0.46%and 0.65%respectively.Mica concentrate can be used as mica by-product;Feldspar products can be used as first-class products in flat glass.The screening analysis and microscopic identification of the tailings show that the lost K₂O and Na₂O are mainly concentrated in the+0.15 mm size fraction.Part of the feldspar and quartz in this size fraction form syntectic particles,and some of them are wrapped by quartz,which are difficult to dissociate and are difficult to recover.The activation of feldspar by sodium fluoride under acidic conditions was studied by means of photoelectron spectroscopy,time-of-flight secondary ion mass spectrometry,zeta potential measurement and hydrolysis equilibrium of sodium fluoride.The results show that the mechanism of activation of feldspar by sodium fluoride is:in acidic medium,hydrofluoric acid produced by hydrolysis of sodium fluoride dissolves Si-O bond in feldspar,exposing more active ion Al³⁺on its surface,The F-containing ions are mainly adsorbed on the Al³⁺region of feldspar surface in the form of F^-,which increases the negative charge of feldspar surface and is more conducive to the electrostatic adsorption of cationic collectors.