Abstract:

Manganese residue is an acidic filter residual produced in the process of producing manganese sulfate using pyrolusite,and bauxite residue（red mud） is an alkaline waste derived from Bayer process of producing alumina.Both of the two kinds of waste residues have large amounts of discharge and low comprehensive utilization rates.Manganese residue and red mud were used as raw materials to prepare adsorbents by mixing and roasting,through which the two kinds of waste residues can be neutralized and the pH of the prepared adsorbent is close to neutral.The adsorption property of the manganese residue-bauxite residue adsorbent on copper ion was studied.And a new route for comprehensive utilization of waste residues was provided.Effect of the conditions,such as adsorption time,initial mass concentration of Cu ²⁺ in solution and pH of solution etc.,on the Cu ²⁺ in solution of adsorbent were investigated.Results showed that the adsorption equilibrium time of Cu ²⁺ was 22 h by the adsorbents under different roasting temperatures.The adsorbent prepared under the roasting temperature of 700 ℃（A700） presented the best capacity on the adsorption of Cu ²⁺.Under the conditions of solid-liquid mass-volume（g/L） ratio of 0.4∶1,The concentration of copper ion in the solution can be reduced from 20 mg/L to 0.053 mg/L atthe adsorption equilibrium,the adsorption capacity was as high as 45.739 2 mg/g and the adsorption rate on Cu ²⁺ was 99.72%.The adsorption behavior of adsorbent A700 on Cu ²⁺ was demonstrated following the pseudo first-order kinetic model and Langmuir isothermal adsorption model.

Key words: manganese residue, bauxite residue, copper ion, adsorption experiment