Study On Floatability Of Collophane And Dolomite And The Absorption Property Of The Collector On Its Surface

Flotation is the main method for beneficiation of middle and low grade calcium magnesium phosphate ores,and the adsorption of collectors on the mineral surface is the key to the high efficiency flotation separation.The study on the relationship between the adsorption properties of collector and floatability of the collophite and dolomite is of great guiding significance for the high efficiency flotation of low and middle grade calcium magnesium phosphate ores.The effects of mineral particle size,pulp pH and collector GJBW concentration on the flotation behavior of collophite and dolomite were investigated by pure mineral flotation test.The effects of mineral particle size,pulp pH,GJBW concentration and pulp temperature on the adsorption behavior of GJBW on the surface of collophite and dolomite were investigated by adsorption measurement system.Finally,the GJBW adsorption mechanism of collophite and dolomite surface is further revealed by analysis of angle,surface tension,Zeta potential and microcalorimetry.The flotation test results of pure mineral show that the floating rate of phosphorite and dolomite rises first and then decreases with the decrease of grain size,and the floating rate difference is better when the size composition is 45-75 um.In acid conditions,the flotation separation of phosphorite and dolomite can be achieved,while the alkaline condition is not good for separation.When the pH value is 4,the difference between the floating rate and the floating rate is large.It is a suitable flotation separation condition.When the pH was 4,the concentration of GJBW increased from 0 to 350 mg/L,the dolomite floated first grew and then decreased,and the floating rate of the phosphate rock increased gradually.At 200 mg/L,the floating rate of dolomite reached the maximum,and the difference between the floating rate of the two minerals was the largest,so the GJBW concentration of the two floatation separation was 200 mg/L.The adsorption test results show that with the decrease of the size of phosphorite and dolomite,the adsorption of GJBW on the surface of phosphorite and dolomite increases,which is due to the increase of the specific surface area with the decrease of the size of two minerals.With the increase of pH value,the adsorption amount of GJBW on the phosphorite and dolomite surface first increased and then decreased,and the difference of adsorption capacity gradually decreased.When the pH value is 4,the difference between them is larger.When the pH value is 10,the GJBW adsorption capacity reaches the maximum.The adsorption amount of GJBW on two kinds of minerals increased gradually with the increase of its concentration,and increased faster than 350 mg/L.The adsorption capacity of GJBW on two kinds of minerals increases with the increase of temperature,and the adsorption capacity of dolomite is greater than that of phosphorite.With the increase of GJBW concentration,the contact angles of both the phosphorite and dolomite surface first rise and then decrease,and the contact angle difference increases gradually,and the difference value is larger when GJBW concentration is 200 mg/L.With the increase of the pH value,the contact angles of the phosphorite and dolomite surface first rise and then decrease,and the contact angle difference between them decreases gradually,difference value is smaller when the pH value is 4.The concentration of GJBW has little effect on the surface tension of the solution,but it decreases first and then rises with the increase of pH value,and reaches the minimum at the pH value of 10,while the increase of temperature will reduce the surface tension of the solution.The Zeta potential value of the two minerals increased first and then decreased with the increase of the concentration of GJBW.Dolomite reached the maximum when the concentration of GJBW was 150 mg/L,while phosphorite at 200 mg/L;the Zeta potential of the minerals increased with the increase of the pH value.Before and after GJBW adsorption,the characteristic peaks of infrared spectra of minerals are basically unchanged.The first order kinetics,two stage dynamics and the Webber-Morris adsorption model were fitted.The results showed that the adsorption of collophite and dolomite to collector GJBW was in accordance with the pseudo two kinetic model.And the K value of the collophane was 0.2037 and the equilibrium adsorption capacity Qe was 5.3302 mg/g,when the K value of dolomite was 0.1424 and the equilibrium adsorption capacity Qe is 3.2252 mg/g.The adsorption isotherms of GJBW on the mineral surface were fitted with Langmuir model,Freundlich model and Linear equation.The results showed that the adsorption of GJBW on the surface of phosphorite and dolomite was closest to Langmuir monolayer,and the maximum adsorption amount was 5.9218 mg/L and 4.6875 mg/L respectively.At the same time,the results of microcalorimetry indicate that acidic conditions,elevated temperature and concentration of 200 mg/L collector are favorable for flotation separation of collophane and dolomite.When the pH value is 10,the reaction heat of the two minerals is the largest with that of the GJBW;The reaction heat of GJBW on the surface of collophite at 50℃ is less than 30℃.When GJBW 200 mg/L,the reaction heat of GJBW on the collophite surface is less than that at 350 mg/L.But the dolomite is opposite to that.