Study On Synergistic Removal Mechanism Of Mercury And Sulfur By Modified Activated Carbon

With the rapid development of the metallurgical industry and the improvement of related theories,environmental pollutants sulfur dioxide and mercury emitted by metallurgical processes have gradually attracted people’s attention,and the state has imposed stricter requirements on sulfur dioxide and mercury control.As a heavily polluting industry in the steel industry,it is particularly important and urgent to study the collaborative control of sulfur dioxide and mercury.A series of modified activated carbons,such as Fe Cl₃/AC,Mn Cl₂/AC,and Cu Cl₂/AC,were prepared by the impregnation method with columnar activated carbon（AC）as the carrier.By controlling the influencing factors such as active components,modification solution concentration,roasting temperature,reaction temperature,initial SO₂ concentration and O₂ concentration,the effects of preparation conditions and process conditions on the mercury removal and desulfurization performance of modified activated carbon were studied.Combined with SEM,XRD and nitrogen adsorption,the mechanism of synergistic removal of mercury and sulfur by modified activated carbon was analyzed.The results show that after the activated carbons are modified by the transition metals Fe³⁺,Mn²⁺and Cu²⁺,their demercuration and desulfurization performance are significantly improved,and Fe Cl₃/AC has the best demercuration and desulfurization performance.The optimal preparation conditions of Fe Cl₃/AC are 0.15 mol/L modified solution concentration and 300℃roasting temperature.The optimal process conditions for Fe Cl₃/AC are a reaction temperature of 60°C,an initial SO₂ concentration of 3000 ppm,and an O₂ concentration of 3%.At this time,the Fe Cl₃/AC’s mercury removal and desulfurization performance reach the maximum,and the maximum mercury adsorption capacity and penetrating sulfur capacity are 0.8877 ng/g and 28.9 mg/g,respectively.Combining SEM,XRD,and nitrogen adsorption characterization methods,the analysis found that:1)After the activated carbon is modified,the specific surface area and total pore volume are reduced,while the average pore size is increased to varying degrees.2)The metal oxides attached to the surface of the modified activated carbon are Fe₂O₃,Mn O₂ and Cu O,respectively,which can promote the cooperative removal of Hg⁰ and SO₂.Figure 29;Table 12;Reference 67...