Manganese oxides have high specific surface area,high porosity and rich surface hydroxy groups,thus have good adsorption properties and good removal effect for heavy metal ions,and are often used as an adsorbent.This paper mainly explores the manganese sulfate solution for the control of high purity manganese oxide,and then performs the adsorption verification of cobalt and nickel heavy metal ions.In order to explore the effects of different oxidizers on products when oxidized manganese sulfate solution in situ,and the advantages of H2O2as an oxidant,H2O2,sodium hypochlorite,potassium permanganate and oxygen as an oxide agent,oxidize the manganese sulfate solution for SEM,EDS,XRD,BET,infrared analysis to verify the advantages of H2O2as an oxidant.The results showed that the manganese oxide particles of H2O2have the smallest diameter,about 50nm;the oxidation degree of different products is follows:the>sodium hypochlorite of>oxygen produced by potassium permanganate.The potassium permanganate as the oxidizer can introduce a large amount of K impurities in the solution;the product produced by hydrogen peroxide has the largest specific surface area,63.8764 m2/g.In general,the product made with H2O2as an oxidizer has the advantages of smaller particle diameter,higher oxidization,maximum specific surface area,rich surface oxy,without other impurities,and is most suitable as an oxidizer of manganese sulfate solution.In order to control high purity manganese oxides with high adsorption properties,the manganese sulfate solution with H2O2as the oxidizer under different conditions to prepare different manganese oxides.The chemical properties of manganese oxide under different oxidation agent dosage,reaction time,reaction temperature,reaction p H and Mn2+concentration were investigated.The results show that the optimal condition is temperature 25℃,p H is 3,the time of 90min,oxidizer n(H2O2):n(Mn2+)is 1:1,Mn2+concentration of 10g/L,the manganese oxide is the largest surface area,and the theoretical adsorption performance of manganese oxide is the greatest.The crystal type of the product isγtype MnO2,The microscopic shape is composed of about 50~60nm;The specific surface area of the product and the size of the particle diameter in its microscopic morphology exist,That is,the smaller the diameter of the nanosphere particles,The larger the specific surface area,The greater the adsorption potential of heavy metal ions;Temperature conditions have a great influence on the microscopic morphology of the product,As the temperature rises,The length of the nanorod is gradually becoming shorter,When the temperature rises to 40℃,The bar becomes a ball;Response p H has a great influence on the material phase composition of the product,As the p H drops from 9 to 6,Mn3O4gradually away,The phases of MnOOH and-MnO2began to appear,As the p H drops from 6 to 3,The MnOOH gradually disappears in the product,When the p H drops to 3,All-MnO2 in the product.The Mn3O4generated under alkaline conditions will also decompose into Mn2+and MnO2under acidic conditions.Controlling micro morphology,phase composition and specific surface area are realized.The nano MnO2 made by H2O2 in situ oxidation is an adsorbent to remove cobalt and nickel impurities from 100m L manganese sulfate and verify its adsorption properties.The effects of different reactions,p H,adsorbent dosage and reaction time conditions on the adsorption effect were investigated.The results show that the best condition except miscellaneous is reaction p H of6 and reaction time of 30min,adsorbent is 1.0g.The content of cobalt-nickel impurities in the manganese sulfate solution was 0.66mg/L and 1.313mg/L,respectively,and the removal rate was94.59%and 95.67%,respectively.It meets the industrial process standard of high purity manganese sulfate(HG/T4823-2015)for battery.Through the above experiment,it is determined that the product made with H2O2as oxidizer has a smaller particle diameter,higher oxidation degree,maximum specific surface area,rich surface hydroxyl group without other impurities;during the preparation of manganese oxide,the controllable technical means of preparing manganese oxide with higher specific surface area is determined,and controlling the product morphology and material composition by controlling the temperature and p H.Guiding the preparation of manganese oxides,it provides a new method of high efficiency,pure,recyclable adsorbent for the preparation of high-purity manganese sulbent solution. |