The Desulphurization And Simultaneous Treatment Of Wastewater From Blast Furnace By Pulsed Corona Discharge Plasma

On the base of the characteristics of higher cyanide in the wastewater from blast furnace and low concentration of SO2 in sintering flue gas, and the physicochemical feature of pulsed corona discharge plasma, the investigation was conducted into the feasibility of SO2 removal from simulated flue gas and simultaneous treatment of wastewater from blast furnace by pulsed corona discharge. Two aspects were researched: the result of desulphurization with wastewater from blast furnace by pulsed discharge and the result of treatment of wastewater from blast furnace by pulsed corona discharge.The experimental results show that wastewater from blast furnace has excellent ability of desulphurization, pulsed corona can enhance the removal ratio of SO2. The SO2 removal ratio can reach 92.0% when test were conducted within the following parameters: the water flow was 51L/h, the flue gas flow rate of 18Nm3/h, the simulated gas temperature of 80℃, the inlet temperature of wastewater of 23℃, the applied voltage was 27KV and SO2 initial concentration was about 1430mg/m3. In addition, the SO2 removal ratio decreases along with the increment of cycle index, the removal ratio increases when the flow rate of wastewater from blast furnace increases, while it decreases when the flue gas flow arises and the inlet temperature of wastewater arises.The experimental results indicate that wastewater from blast furnace can be treated well by the pulsed corona discharge, during which SO2 was removed at the same time. The cyanide and ammonia nitrogen content was decreased about 99.9% and 20%, when the residence time of wastewater from blast furnace in the pulsed corona zone was 2.1s with a 12KV pulsed voltage.Moreover, the higher the concentration of cyanide the better removal effect of cyanide. In addition, the more the cycle indeies the more sulfate radical were generated, and the quantity of sulfate radical produced with discharge more than without it. Moreover, the higher the pulsed voltage and the flue gas flow rate the higher concentration of sulfate radical was generated.The research acchivements prove that this new technique has an excellent desulphurization effect and can effectuively remove cyanide in wastewater from blast furnace simultaneously. As a result, this new technology can be implemented for treating wastewater from blast furnace and desulphurization from sintering plant, which initiates a new way of using waste controlling waste.