Ultrasonic-enhanced Trial And Mechanism Study Of Pyrite Flotation

In China’s non-ferrous metal mines,easily selection of the single pyrite deposits are very seldom,and the high sulfur mixed ore with high pyrite content accounts for the majority.Natural pyrite have a better hydrophobicity in the anaerobic environment,However,when pyrite are exposed to the air or aqueous solution conditions,the surface is easy to generate iron oxides or hydroxides,which is resulted in pyrite oxidation and the surface hydrophobicity decreased.Ultrasonic treatment is a very good assistant way to improve the floatability of oxidized pyrite.This paper takes pyrite as the research object,the effect of ultrasound have an effect on the flotation effect of pyrite and flotation kinetics of pyrite different particle size under ultrasonic effect are studied.on this basis,the thesis carrys on research on the strengthening effect of ultrasonic on the surface properties of pyrite,in order to reveal the mechanism of ultrasonic wave strengthening pyrite flotation.The properties of pyrite ore were studied in a concentrator in Yunnan.Through the multi element analysis,it is found that the content of S is 14.51%in the raw ore,and the content of the main valuable metal elements is low,gangue minerals are mainly quartz and calcium,aluminum,magnesium silicate.Through flotation test,floatation effectiveness of pyrite under conventional and ultrasonic effect conditions are compared,the test results show that the pyrite recovery rate increased gradually in the roughing process with the increase of ultrasonic power.when the ultrasonic power is increased to 70W,the pyrite recovery rate reached maximum value(89.32%).compared with the conventional under the condition,the pyrite recovery rate increased by 10.85%.The recovery of pyrite is also improved in concentrate process of ultrasonic action,but the process of scavenging and pretreatment is not obvious.Flotation kinetics of pyrite different particle size under ultrasonic effect was investigated.The final results show that the optimum size of the pyrite flotation mineral under roughing and concentrate process of ultrasonic effect conditions was-74+45μm.In the optimum size of the flotation mineral,ultrasonic can increase the roughing and concentrate recovery of pyrite.Comparison pyrite under the conventional flotation conditions,they were increased by 6.17%and 6.06%,respectively.Six flotation kinetic models were selected.In Origin 8.6,the flotation recovery results of pyrite with-74+45μm under ultrasonic irradiation carry on the nonlinear regression fitting analysis,it was found that the fitting effect of the classical first dynamic model under roughing process is the best.It can be expressed as:ε=39.5271[1-exp(-0.841t)]However,in the process of concentrate,the fitting effect of the first dynamic model of rectangular distribution is the best.It can be expressed is:ε = 42.631{1-1/1.775t[1-exp(-1.775t)]}The effect of ultrasonic wave on the surface properties of pyrite was studied.Contact angle analysis found that 0.3W/cm2 or higher intensity of the ultrasound display on the surface of pyrite with cleaning and oxidation.Scanning electron microscopy analysis found that ultrasonic have the cleaning and erosion effect on the surface of pyrite,it can remove the impurities adhered to the cover surface of pyrite and some harmful minerals contained in pyrite.Pyrite oxidation of 12min and 20min in H2O2 solution,respectively,represents mild oxidation and severe oxidation.The results showed that the surface was subjected to a certaindegree of oxidation after 12 min and 20 min reaction in H2O2 solution,and the concentration of oxygen was significantly affected by ultrasonic treatment.In the mild oxidation,the ultrasonic effect of 20s time can effectively removed to cover the pyrite surface of the oxidation products.Under the severe oxidation,the oxygen concentration increases to acertain extent when the ultrasonic treatment time vary from 10s to 50s,ultrasound can play the oxidation role in the surface of pyrite.