Recovery Of Molybdenum And Rhenium Richment By Ion Exchange From Molybdenum Smelting Waste Acid

Rhenium?Re?is scare metal,with high density,high boiling point,high melting point,excellent catalytic activity,excellent ductility,formability and other characteristics,plays an irreplaceable role in the fields of superalloy preparation,hydrogenation catalysts and other fields.Molybdenum has excellent physicochemical properties and is mainly used as an alloy steel and stainless steel additive in the steel field.Rhenium has no independent deposit,is mainly associated with molybdenite,and is recovered as a by-product of molybdenum smelting.In the existing molybdenum smelting process,rhenium is mainly enriched in molybdenum smelting dust and roasting eluent.In order to ensure the yield of molybdenum,soot is often returned to the roasting process,and then the molybdenum smelting roasting eluent becomes the important raw materials for the recovery of rhenium.Extraction method and ion exchange method are the main methods for recovering rhenium from molybdenum smelting waste acid.Among them,the extraction method is relatively mature and has industrial application.However,the organic content in the raffinate solution exceeds the standard and the water treatment is difficult.In view of the recovery and utilization of molybdenum?VI?and antimony?VII?in molybdenum smelting waste acid,this subject adopts ion exchange technology to explore suitable process conditions and provide technical support for the recovery of molybdenum and rhenium in the molybdenum smelting waste acid.According to the static adsorption process of leaching resin,the volume ratio of ammonium perrhenate solution containing Re concentration of 200 mg/L and leaching resin is 150:1.The increase of pH value is unfavorable to the process of adsorption of Re by leaching resin,and the smaller pH value range is favorable for the adsorption.The increase of temperature is unfavorable to the adsorption of Re ions by leaching resin,and adsorption at normal temperature is proper.The changes of impurity ions SO₃^2-,SO₄^2-,and F^-in the solution will reduce the adsorption rate of Re on the leaching resin,and SO₃^2-has great influence on the adsorption process of Re at the same concentration.The dynamic adsorption and desorption process of leaching resin was optimized,and the suitable dynamic adsorption parameters were obtained:the pH value of molybdenum smelting waste acid is 0 to 1.5,and the flow rate is 0.5 BV/h,and it is adsorbed at normal temperature;the suitable dynamic desorption conditions are as follows:the dynamic desorption uses 2.5%ammonia,with 1 BV/h flow rate at normal temperature,the desorption rate of Re is 98.81%and the rhenium is enriched to 12 g/L.Adopting leaching resin,the content of organic matter in the liquid after adsorption is 41 mg/L,compare with 403 mg/L of the extracted liquid,the organic content in the liquid after adsorption is dropped by89.83%.According to the static adsorption process of D314 resin,the volume ratio of ammonium molybdate solution containing Mo concentration of 1 g/L and D314 resin is 150:1.As the pH value increases,the adsorption rate of Mo adsorbed on D314resin increases first and then decreases,and the pH value is selected in the vicinity of4 for adsorption.The increase of temperature is favorable for the adsorption of Mo by D314 resin,and adsorption studies at room temperature is selected considering the economy of the process.The changes of impurity ions SO₃^2-,SO₄^2-,and F^-in the solution will reduce the adsorption rate of Mo on the D314 resin,at the same concentration,SO₃^2-has great influence on the adsorption process of Mo.The dynamic adsorption and desorption process of D314 resin was optimized,and the suitable dynamic adsorption parameters were obtained:the pH value of molybdenum smelting waste acid is about 4,and the flow rate is 0.5 BV/h,and it was adsorbed at normal temperature;The suitable dynamic desorption conditions were as follows:the dynamic desorption uses 10%ammonia,with 1.5 BV/h flow rate at normal temperature,the desorption rate of Mo is 98.81%and the molybdenum is enriched to70 g/L.According to the thermodynamics and kinetics of the adsorption process of the leaching resin,thermodynamic studies show:the adsorption process of Re is an exothermic process,the increase of temperature is unfavorable to the adsorption process of Re,and the Freundlich isothermal equation can better reflect the adsorption equilibrium relationship between the leaching resin and the Re.The kinetic study shows:the pseudo-second-order kinetic model well fits the Re ion adsorption process,and particle diffusion is the main rate-control step for this adsorption process.According to the thermodynamics and kinetics of the adsorption process of D314 resin,thermodynamic studies shows:the adsorption process of Mo is an enothermic process,the increase of temperature is favorable to the adsorption process of Mo,and the Langmuir isothermal equation can better reflect the adsorption equilibrium relationship between D314 resin and the Mo.The kinetic study shows:the pseudo-second-order kinetic model well fits the Mo adsorption process,and particle diffusion is the main rate-control step for this adsorption process.