Flotation Performance And Mechanism Of A New Collophane Reverse Flotation Collector

Phosphate rock as a kind of non-renewable resources is an important chemical raw material.Collophane as one of phosphate rock associates with large amounts of dolomite and calcite gangue minerals.As the gangue minerals and collophane have similar physical and chemical properties,it is difficult to separate dolomite from collophane.This is also a difficulty in flotation separation.In this paper,anionic collector D₁₂ in collophane flotation was studied.The collector collophane flotation behavior of dolomite and quartz under different pH and concentration of D₁₂ was studied through single mineral experiments.And the surface tension test,infrared spectrum analysis,Zeta potential and pyrene fluorescence analysis method were employed to interpret the action mechanism between D₁₂ and collophane/dolomite.And the D₁₂ was applied to the actual one collophane reverse flotation technology,achieved good separation effect.The collector collophane flotation behavior of dolomite and quartz under different p H and concentration of D₁₂ was studied through single mineral experiments.The results show that single mineral experiments,collophane recovery rate improves with the increase of pH in presence of D₁₂,that is to say,recovery rate is low under acid condition,but high in alkaline condition.Similarly,dolomite recovery rate increases with the increased pH,and it reach highest at a pH of 12.0.However,quartz recovery rate is low under different pH value.In addition,in artificial mixed mineral test,collophane and dolomite in the mixed ore have a good separation effect in presence of D₁₂ under the condition of adding inhibitor.The Surface tension test,zeta potential,infrared spectrum analysis and pyrene fluorescence analysis are adopted,and the results are as follow.The critical micelle concentration of D₁₂ in aqueous solution is between 20 to 40 mg/L.it changes in different degree under various pH and concentration of D₁₂.When pH is higher than 4.4,the electronegativity of dolomite surface is more negative than that of the cellophane.By contrasting the infrared spectra of collophane and dolomite before and after D₁₂ treatment,the absorption peaks of D₁₂ do not appear in collophane,but the ester characteristic absorption peak of D₁₂ appears on the dolomite.And the results of pyrene fluorescence spectrum between D₁₂ and dolomite with different concentrations of D₁₂ show the value of I₃/I₁ rise gradually with the increasing D₁₂ concentration?0¹2 mg/L?,and it almost no longer changes when the D₁₂ concentration is up to 12 mg/L.At this point,D₁₂ forms a state of half micelle.The action mechanism between D₁₂ and collophane/dolomite was as follow:Under the condition of acid,physical adsorption is main interaction between collophane and D₁₂,and the counterbalance ion from D₁₂ adsorb on the surface of collophane due to the electrostatic force in adsorption and surface,The potential negativity of dolomite increases after D₁₂ adsorption when the pH is controlled in 4.4.The surface of D₁₂ and collophane are negatively charged,and the hydrophobicity of dolomite surface enhanced with the increase of D₁₂ concentration.When the concentration increases to a certain extent,D₁₂ forms a half micelle adsorption in the surface of dolomite.The single reverse flotation process with a rough order of middlings and a fine second sweep back was adopted which D₁₂ was used as reverse flotation collector adopt.In this process,undressed ore grade of P₂O₅ was 22.06%and MgO was 5.94%,and the grinding fineness of 0.074 mm was about 87.33%.On the condition of roughing,the dosage of H₂SO₄,citric acid and collector were 7 Kg/t,1.5 Kg/t and 0.5 Kg/t respectively.In cleaning stage,the dosage of sulfuric acid and collector were 5 Kg/t and 0.3 Kg/t,and the concentrate grade of 31.02%,recovery of 68.64%with open circuit can be obtained under the condition.Moreover,the concentrate grade of 30.31%,recovery of 84.47%and content of MgO of 0.92%with closed-circuit beneficiation indexes was obtained.D₁₂ with good water solubility,strong collecting ability,low temperature resistance,has a good application prospect.