Experimental Study On Enrichment And Impurity Removal Of Ionic Rare Earth Ore Leaching Solution

Based on the leaching liquid of ionic type rare earth ore,this article researched the process of enrichment rare earth from the leaching liquid of ionic type rare earth ore by resin adsorption technology for its series of problems,such as the rare earth concentration of ionic rare earth leaching liquid is low,the huge volume of liquid,precipitation treatment difficulty.Study on the modification of ACT resin which containing high concentrations of active groups?-COOH?by chloroacetic acid.Through single factor and orthogonal experiment,the influence of different factors on the substitution degree of carboxymethyl group was determined: Modifier concentration > solid-liquid ratio > temperature > time.The results showed that the process parameters is optimum when Chloroacetic acid is 8 %,solid-liquid ratio 2:100,temperature 333 K and modification time 2.5 h for modification ACT resin.Under this condition,the substitution degree of carboxymethyl for CB-ACT resin is 0.943.The leaching liquid of ionic type rare earth ore was enriched by CB-ACT resin.In static adsorption experiments.In the static adsorption experiment,the influence of the pH of adsorption liquid,the substitution degree of carboxymethyl,adsorption temperature,adsorption time and rare earth ion initialconcentration in static desorption process were studied.The desorption reagent selection and resin regeneration in the static desorption process also were studied.Static adsorption tests showed that:the stronger acidity,the smaller the static adsorption capacity of CB-ACT resin for rare earth ions,while the pH is close to 6,the precipitates of rare earth were formed which cause losses.The CB-ACT resin has fast adsorption rate for rare earth ions,the adsorption process is controlled by liquid film diffusion and accords with the Langmuir isotherm equation.the order of the desorption effect is:HCl>HNO₃>H₂SO₄,the resin could recycle after desorptionand soaking by using NaOH solution.Dynamic adsorption tests on RE³⁺ and Al³⁺ of leaching solution Being studied.The effects of flow rate,initial concentration and temperature on the dynamic adsorption curves were investigated.The results of experiment with ?15 mm×130 mm column show that the optimum conditions of dynamic adsorption was: feed flow rate 4 ml·min^-1,concentration of feed 4 g·L^-1,adsorption temperature 308 K.The Al³⁺ could be elution inselective and Separated with rare earth 0.8 mol·L^-1 M?OH?n solution.Under the optimum leaching conditions,the ratio of Al₂O₃/REO in desorption solution can be reduced to 0.34 %.