Study On The Enhanced Flotation And Mechanism Of Phosphorite

When the conventional reverse flotation process is used to flotate the deposited calcium phosphate rock,the acid consumption is high,and the high acidity easily deteriorates the flotation effect.At the same time,the flotation wastewater has high acidity and is difficult to treat.In this paper,the typical sedimentary calcium phosphate rock in Guizhou Province is taken as the research object.The new flotation technology of DH-enhanced dolomite flotation is used to achieve flotation under low acidity conditions and reduce acid consumption.Through conventional flotation technology and new low-acid technology tests,the effects of grinding fineness,activator DH,regulator and collector on the grade and recovery rate of flotation concentrate were studied.The effect of activator DH on the flotation of dolomite and fluoroapatite and its mechanism were studied by means of pure mineral flotation,mineral dissolution and X-ray photoelectron spectroscopy.The conventional flotation test of phosphorus block rock flotation technology shows that under the conditions of grinding fineness of 75%-0.074 mm,dosage of regulator H₂SO₄ and collector BW-1 being 16.2 kg/t and 400 g/t respectively,the concentrate with P₂O₅ grade of 33.60%,MgO content of 1.08%and recovery rate of83.95%can be obtained through a reverse flotation process.The flotation test of the new low-acid phosphorite process shows that under the conditions of grinding fineness of-0.074mm accounting for 75%,activator DH of2000 g/t,regulator H2SO4 of 10.2 kg/t and collector BW-1 of 400 g/t,the concentrate with P₂O₅ grade of 33.95%,MgO content of 1.02%and recovery rate of 83.85%can be obtained through a reverse flotation process.The comparison of the new and old process indicators shows that the amount of low-acid new process regulator H₂SO₄ has been reduced by more than one third,while the concentrate grade and recovery rate have not changed much from the conventional flotation process.The new low-acid process costs 3100 yuan per ton higher than the conventional flotation process.Research on the mechanism of the flotation agent shows that when the dosage of H₂SO₄ is 300 mg/L,the low dosage of DH has a better activation effect on the flotation of dolomite,but has little effect on the floatability of fluoroapatite,which is different from the actual mineral flotation.The results are consistent.The hydrolysis of DH dissolved ions affects the pH of the system.Fluoride ions react with calcium ions dissolved in the pulp to form calcium fluoride.As fluoride ions increase,fluoride ions combine with calcium on the surface of dolomite,inhibiting further dissolution of dolomite.These factors can all affect the flotability of dolomite.X-ray photoelectron spectroscopy studies have shown that CaF₂ is formed on the surface of dolomite after interacting with DH,and fluorite on the surface of dolomite is the main reason for DH activation of dolomite.Dolomite has stronger adsorption of oleic acid than fluoroapatite.Dolomite is more hydrophilic than fluoroapatite.The addition of fluoride ion improves the adsorption capacity of oleic acid on the surface of dolomite.