Preparation Of Adsorbent Based On Manganese Residue And Adsorption Of Cu(?)

Manganese sulphate residue is a byproduct of the production of manganese sulphate,an acid filter residue.Red mud is an alkaline waste residue produced in the process of alumina production.The amounts of the two kinds of waste residues discharged are big,and their comprehensive utilization degree is low.In this study,the physical and chemical characterization of raw materials was firstly carried out,and a kind of adsorbent was prepared from manganese residue by hydrothermal transformation.The physical and chemical properties of the adsorbent,including phase structure,chemical composition,were characterized by XRD,XRF,FTIR,and Raman.The results show that the main chemical composition of the adsorbent is iron hydroxide,which is called iron-based adsorbent.The effect of iron-based adsorbent on removing copper ions in aqueous solution was studied.The adsorption efficiency of copper ions at different contact time,initial concentration,pH value and reaction temperature was investigated by batch experiments.The experiment result shows that:?1?The adsorption equilibrium time is 3 h,and the pH value is the optimal pH?pH⁵.5?under natural conditions.Increasing the initial Cu²⁺concentration and reaction temperature can increase the adsorption amount.?2?At natural pH and room temperature,the adsorption capacity of iron hydroxide with initial concentration of 50 mg L^-1 to copper ions was 14.515 mg g^-1.?3?According to the adsorption data,the pseudo-second-order model can describe the adsorption kinetics of copper ions well,while the Freundlich model has a good fitting to the adsorption isotherm.Therefore,the adsorbent from manganese sulfate residue is a promising material for removing copper ions from aqueous solutions.Using manganese residue and red mud as raw materials,mixtures were roasted to prepare manganese residue-red mud adsorbent.The neutralization of two kinds of waste residue was realized,the prepared adsorbent has a pH close to neutral.The adsorption property of the manganese residue-red mud adsorbent on copper ions was investigated,the adsorption effect of manganese residue-red mud adsorbent on Cu²⁺in solution was investigated under the conditions of initial concentration of copper ion and pH value of adsorption time.The results indicate that:?1?A certain roasting temperature can improve the adsorption performance of the adsorbent from manganese residue to red mud,and the adsorption equilibrium time of the adsorbent on Cu²⁺at different roasting temperatures is 22 h.?2?The adsorbent?A700?with the roasting temperature of 700?had the best adsorption effect on Cu²⁺.Under the condition of the solid-liquid ratio of 0.4g:1000 mL,the concentration of copper ions in the solution could be reduced from 20 mg L^-1 to 0.053 mg L^-1,the saturated adsorption amount was 45.739 mg g^-1,and the adsorption and removal rate of copper ions reached 99.72%.?3?The adsorption of Cu²⁺by adsorbent A700 conforms to the quasi-first-order kinetic model and the Langmuir isothermal adsorption model.Finally,the light coarse aggregate prepared by high temperature sintering with manganese residue as the raw material,mixed with red mud of different proportions,was studied.The performance tests of its stacking density and water absorption were carried out.The results show that the light coarse aggregate conforms to the National Standard?GB/T 17431.1-2010?and is a new type of light coarse aggregate.