Experimental Study On Treatment Of Acid Mine Drainage Containing Iron And Manganese By Magnetic Seed Adsorption Flocculation And Ferrite Process

In order to solve the problem that powdery mineral materials have good removal effect on heavy metal ions,but it is difficult to separate mud from water,a composite material containing magnetic seed is used to treat Fe²⁺and Mn²⁺in acid mine wastewater（AMD）.By adding flocculant to strengthen magnetic seed flocculation,the effect of high-efficiency removal and mud separation under the action of magnetic field can be realized,Then,the flocculated alkaline supernatant was used as part of p H regulator to treat amd wastewater containing Fe²⁺and Mn²⁺by ferrite process,which had good treatment effect.Based on fly ash,calcium carbide slag,red mud and steel slag,this paper compares the removal effect of single material on Fe²⁺and Mn²⁺in AMD and the performance of magnetic seed of the four materials.It is found that calcium carbide slag has the best treatment effect but lacks magnetism.The magnetism of magnetic seed in steel slag is the strongest.A small amount of calcium carbide slag is added to steel slag as magnetic seed adsorption flocculation composite material.The results show that the composite material with the mass ratio of steel slag to carbide slag of 7:3 has better removal effect and can meet the requirements of turbidity after magnetic seed adsorption flocculation magnetic separation.The influencing factors,influencing rules,optimal reaction conditions and adsorption flocculation performance of 7:3 steel slag calcium carbide slag composite for AMD containing Fe²⁺and Mn²⁺were studied.The results showed that the dosage of composite,reaction time,initial concentration,oscillation speed and p H value of water sample had obvious effect on effluent p H;When the dosage was 2.0 g/L,the shaking speed was 120 r/min,the initial p H was 3,the initial Mn²⁺concentration was 100 mg/L,the reaction time was 10 min,the initial Fe²⁺concentration was 200 mg/L,and the reaction time was 5 min,the Fe²⁺and Mn²⁺were almost completely removed,but the effluent p H was more than 12.The adsorption properties of Fe²⁺and Mn²⁺treated by the composite accorded with Langmuir isotherm model and quasi second order kinetic model.The removal of Fe²⁺and Mn²⁺by composite materials includes adsorption,chemical precipitation,complexation,ion exchange and flocculation.When the dosage of PAM was 1.0 mg/L in the stage of magnetic seed adsorption flocculation magnetic separation,compared with the effluent turbidity before and after the effect of magnetic field,the effect of magnetic separation was significant,and the effluent turbidity was 9.5 NTU.When the molar ratio of Fe²⁺:Mn²⁺is greater than 4,the molar ratio of M³⁺:M²⁺is 1.4,the p H is adjusted to 10,the reaction is stirred at 120r/min for 30min,and the reaction is still for30min,the removal rate of Fe²⁺and Mn²⁺is close to 100%,and the ferrite precipitation product has strong magnetism,The magnetic separation effect is remarkable,the effluent turbidity is low,the p H is about neutral,and the ferrite precipitate can be recycled.The paper has 40 pictures,22 tables,and 94 references.