Study On Purification Process Of Fluoride Ion In Citrate Desorption Liquid

Fluoride is present in the primary minerals.During the purification process of citrate wet flue gas desulfurization in the metallurgical industry,the fluoride ion accumulates and its concentration increases.In the acidic and high temperature environment,fluoride ion corrosion is extremely strong,serious damage to the purification equipment,and thus seriously affect the production process.Therefore,the pursuit of efficient energy-saving,does not produce secondary pollution and cost-effective fluoride removal technology is an important issue in fluoride research.Therefore,the pursuit of efficient energy-saving,does not produce secondary pollution and cost-effective fluoride removal technology is an important issue in fluoride research.In this paper,according to the characteristics of La F3 with extremely low solubility product,it is suggested that La2(CO3)3 is used as precipitant in the acidic environment,and it is studied in the acidic environment.The main factors affecting the purification process were discussed,and the reaction mechanism was discussed preliminarily.This study is expected to develop a process and technique for the selective precipitation and separation of F-in acidic solutions,as well as a way and means for the relevant research and improvement of existing purification methods.The thermodynamic data of various precipitants were obtained by thermodynamics calculation of aluminum series precipitant,calcium series precipitant and lanthanum series precipitant at different temperature and p H respectively.The data show that aluminum series precipitants,calcium series precipitants and lanthanum oxide are suitable for reaction with sodium fluoride in low p H and low temperature environment.Lanthanum carbonate is theoretically possible in the range of p H range and high temperature environment.Sodium fluoride reacts.In this study,a simple NaF solution was used to study the reaction time,the p Hvalue of the solution,the reaction temperature and the amount of the precipitant.The precipitates and precipitated products were characterized by infrared spectroscopy/XRD and the zeta potential of the precipitant was determined and analyzed.The results show that the reaction process of lanthanum carbonate precipitation purification is mainly due to the direct reaction of lanthanum carbonate with Na F,and the reaction of lanthanum carbonate with F-.The optimum reaction conditions were as follows: the reaction time was five minutes,the p H value of the solution was 2.5,the reaction temperature was40?,and the dosage of lanthanum carbonate was 3 times of the theoretical amount.The macroscopic equation of the F-process kinetics of the lanthanum carbonate precipitation was calculated by the single factor experimental data.The increase in p H has an inhibitory effect on the reaction,The addition of lanthanum carbonate has a gain effect on the reaction,the activation energy is E=0.5632KJ/mol.The effects of reaction time,reaction p H,reaction temperature,amount of lanthanum carbonate,citric acid concentration and F-concentration on the removal efficiency of lanthanum carbonate were investigated in this paper.And finally get better fluoride removal conditions.Studies have shown that citrate precipitation,the lanthanum carbonate precipitation purification F-basic trend is not affected much,only because of the buffering effect of citrate,the p H changes more stable.Experiments show that the higher the concentration of citric acid,defluorination effect will be worse.The optimum conditions were as follows: p H was 2.5,the reaction time was five minutes,the temperature was 40 ?,and the amount of lanthanum carbonate was 3 times of the theoretical amount.