Study On The Effect Of Mineral Treatment Wastewater Reuse On Flotation Of Phosphate Ore

With the continuous consumption of phosphate rock resources,the rational development and utilization of refractory silicon calcium phosphate is of great significance.Double reverse flotation as one of the most widely used methods for the selection of calcium silicate phosphate,not only the selection effect is good,but also the pharmaceutical system is simple,but at the same time will bring a large number of complex flotation wastewater.When the wastewater is recycled,the inorganic ions and residual chemicals will adversely affect the flotation effect.Therefore,it is very important to study the effect of flotation wastewater reuse on the double reverse flotation of calcium silicate phosphate and reduce the double flotation index when wastewater reuse.In this paper,a low grade silicon calcium phosphate rock in Guizhou was used as the object of study.The optimum grinding fineness,flotation process and pharmacy system were determined by flotation condition test.It investigated the accumulation of major ions and COD in the flotation wastewater,and studied the effects of the main ions and the interaction on the flotation by single factor test and orthogonal test.It has determined the excellent process of returning the wastewater to the flotation system,and on this basis,it further reduces the effect of wastewater reuse on the flotation index through the wastewater coagulation sedimentation treatment.The mechanism of the effect of wastewater reuse on flotation was explained by scanning electron microscopy,XRD,surface tension and so on.The main minerals used in the selected phosphate rock are fluorapatite.The main gangue minerals are quartz and dolomite.The grades of P₂O₅,SiO₂ and MgO are 25.2 %,15.15 % and2.42 % respectively.The best grinding fineness is 82.5 %,and the dosage of sulfuric acid,YW-01 and SEA is 14 Kg/t,1.4 Kg/t and 0.6 Kg/t.Under these conditions,the grade and recovery rate of P₂O₅ in the open-circuit test were 31.57 % and 82.87 % respectively.The grade and recovery rate of P₂O₅ was 30.61 % and 89.38 % in closed circuit test.When the waste water is concentrated and returned to the flotation system,the accumulation of Ca²⁺,Mg²⁺,SO₄^2-,TP,F-and COD in the wastewater is accumulated.The results of single factor test showed that Ca²⁺ and Mg²⁺ decreased the grade and recovery of P₂O₅.A high concentration of SO₄^2-in the wastewater will result in a slight increase in P₂O₅ grade,but will result in a significant reduction in the recovery of concentrate P₂O₅.The grade of P₂O₅ decreased with the increase of PO₄^3- concentration,and the recovery rate increased first and then decreased.The F-concentrationin the flotation wastewater is relatively small,which has little effect on the flotation of the phosphate rock.The effect of SO₄^2-and Ca²⁺ on the recovery of concentrate P₂O₅ was significant,and the effect of Ca²⁺ on the grade of concentrate P₂O₅ was significant by orthogonal test.By comparing the different wastewater return methods,the wastewater treatment process with less impact on the flotation index was determined.Flotation wastewater sequence returned 10 times,concentrate P₂O₅ grade decreased by 1.74 %,the recovery rate decreased by 2.84 %;According to the different water quality,CaO+Na₂CO₃ +PAC+PAFC coagulation sedimentation method were used to treat coarse concentrate filtrate and final concentrate filtrate.The optimum treatment conditions were determined by the condition test of the simulated wastewater.Under these conditions,the actual wastewater treatment and reuse were carried out.The flotation index of the concentrate P₂O₅ was 30.57 % and 89.39 % respectively.There was no difference in flotation results.According to the critical concentration of micelles,the interaction between SEA and YW-01 was calculated by MatLab.The interaction between SEA and YW-01 was also found,which affected the flotation effect.SO₄^2- will affect the surface tension of the collector solution to affect the flotation effect,and the surface tension measurement and energy spectrum analysis show that the effect of SO₄^2- on de-magnesium is higher than that of desiliconization reverse flotation.Spectrometric analysis and XRD analysis showed that the surface of fluoroaluminite attached to the surface of SO₄^2-bound Ca²⁺ precipitated,causing the fluorapatite to emerge with the dolomite.