Study On Removing Process Of Fluorine And Chiorine In Zinc Oxide Flue Gas Desulfurization Products

The lead and zinc smelting will produce a large amount of sulfur containing flue gas.Zinc oxide flue gas desulfurization process is a kind of resource recovery desulfurization technology which is suitable for zinc smelting industry,removal of fluoride and chlorine in products is the key step for resource recovery.The ion exchange and lead oxide method was selected to remove fluorine and chluorine in the subject,the technological characteristics of removal of fluorine and chlorine by ion exchange method were investigated by transformation and modification of the resin,the feasibility of removing fluorine and chlorine from industrial lead oxide was discussed,and the removal effect of chlorine was investigated,the main contents and innovation points are as follows:(1)Through comparison of various transformation agents,it is found that dilute sulfuric acid as the transformation agent is better.The best condition is that the ratio of liquid to solid was 1:1,and it was soaked in sulfuric acid solution with mass concentration of 4%for 4 times,about 4 hours each time.According to the static adsorption rate curve of the 717 resin,using the shrinking core model to process the data,it is found that the particle diffusion is the main step of the process.Behavior of Cl’ in the adsorbed solution of resin conforms to the isothermal equation of Freundlich adsorption.The saturated adsorption capacity of resin increases with the increase of Cl-concentration in solution,and the trend gradually slows down.The temperature and Zn2+ content of the solution had no effect on the amount and rate of adsorption.When pH was neutral,the adsorption capacity was the largest.When the concentration of Cl-increases,the asorbtion rate will increase.When the concentration reaches a certain amount,the rate will not become bigger.(2)Under experimental conditions,the effects of various factors on the regeneration effect was investigated.The temperature and Zn2+content had no effect on the regeneration effect.When the concentration of Cl-increases,desorption efficiency will decrease.The mass concentration of the sulfuric acid is 6%,the result is basically the best and the analytical amount can reach 5.5 mg/ml.After multiple use,the resin can reach its service life and the total adsorption capacity can reach 5.28 mmol/g.By comparing infrared spectra before and after using of resin,the skeleton has no chemical reaction,which shows that the mechanism of the adsorption is the electrostatic force between Cl-and—N+(CH3)3.(3)The breakthrough curves and dynamic analytical curves were obtained through the experiment of dynamic processs.The saturated adsorption capacity of the resin is 34.12 mg/g when the solution flows through the resin column at flow rate of 6 ml/min.According to the analytical curve,the average Cl-content in the analytical solution is 6.32 mg/ml,and the resolution efficiency is 94.6%.(4)The effect of D001 resin modified by aluminum nitrate solution on adsorption of F-has been greatly improved.Under experimental conditions,the best conditions for the modification are obtained:the liquid-solid ratio at 1:10,resin is mixed with the aluminum nitrate solution with a concentration of 0.6 mol/L for 2 hours.The amount of adsorption to F-is about 2.6 mg/g,the optimum reaction is 30 mins.(5)The effect of using industrial lead oxide to remove chlorine is preliminarily investigated.The results show that the removal efficiency of chlorine can reach 45%and the chlorine removal capacity of lead waste with unit mass can reach 5.05 mg/g under the experimental conditions.