Preparation And Application Of Soluble Fluorosilicate

In recent years, with the strong development of China's chemical industry, as well as the rapid development of the world's industry, especially in the rapid development of the aluminum industry, driven by the consumption of fluoride salt significantly increased. Causing the fluoride salt market demand for rapid expansion in the world. Sodium fluorosilicate as a by-product of the phosphate chemical industry, the source is simple and relatively inexpensive, which contains silicon resources and fluorine resources is a very important chemical resources, the use of sodium fluorosilicate to recover silicon and fluorine is of great research value. In this paper,firstly, the silicofluoric acid was prepared by electrolysis of sodium silicofluoride by cationic membrane electrolysis,and then silica silica and ammonium hydrogen fluoride were prepared by amination hydrolysis of fluorosilicic acid, and the silicon resources and fluorine resources were recovered. And then electrolysis of fluorosilicic acid to prepare soluble transition metal fluorosilicate, and the feasibility of using copper fluorosilicate as the main salt of copper plating solution was investigated. The main contents of this paper include the following aspects:1.The fluorosilicic acid solution was prepared by electrolyzing sodium fluorosilicate using a cationic membrane electrolysis method. And the preparation of silicon dioxide and ammonium bifluoride by ammoniation reaction with ammonia, to prove the preparation of electrolytic sodium fluorosilicate solution for the fluorosilicic acid. The production of fluorosilicic acid was investigated by adjusting the current density gradient of sodium fluosilicate prepared by electrolysis. It was found that the silica fused silica had the highest quality, the highest concentration of fluorosilicic acid and the highest conversion rate of sodium fluorosilicate at a current density of 6.25 mA/ cm2. Silica was prepared by ammoniating the previously prepared fluorosilicic acid with aqueous ammonia, the characterization of the prepared silica silica was characterized by XRD,IR and EDX,and its crystal structure and composition were analyzed.It was proved that the prepared silica was an amorphous amorphous structure,and the anodic solution prepared by electrolysis of sodium fluosilicate was proved to be fluorosilicic acid.Ammonium bifluoride was prepared by ammoniation reaction of fluorosilicic acid and ammonia. XRD, IR and EDX were used to characterize the crystal structure and the composition of the product. The results showed that the product was ammonium bifluoride.2. Preparation of soluble fluorosilicate by fluorosilicic acid prepared by electrolysis of sodium fluosilicate with cationic membrane and copper fluorosilicate and zinc fluorosilicate were prepared respectively. The results show that the soluble transition metal fluoride silicate can be prepared by the electrolysis of fluorosilicic acid by cationic membrane electrolysis using XRD,TG and EDX. In this paper, cationic membrane electrolysis is used to electrolyze the fluorosilicic acid for the first time to prepare soluble transition metal fluorosilicate. Using fluorosilicic acid prepared by electrolyzing sodium fluosilicate, copper fluorosilicate and zinc fluorosilicate crystal are successfully prepared. It provides a good idea and method for the application and recovery of sodium fluorosilicate and fluorosilicic acid.3. In this paper, the three-electrode system is used to test the cyclic voltammetry curves of copper in the solution of copper fluoride fluorosilicate at room temperature. It can be seen that the system is not completely reversible. And with the increase of the scanning rate, the potential of the oxidation peak is shifted positively and the potential of the reduction peak is shifted negatively. Under the condition of scanning rate of 80 mV / s, the peak area of monovalent copper ions was larger than that of divalent copper ions, which had a great influence on the quality of coating. As the temperature increases, the peak width of the oxidation peak gradually becomes larger, easy to dissolve copper in copper fluoride fluorosilicate solution. According to the anodic polarization curve of copper in the solution of copper fluoride at room temperature,the potential potential range of the electrochemical dissolution region of copper is 0.053V ?0.243V,and the peak width of the electrochemical dissolution region increases with the increase of temperature. Under the condition of 40 ?,the working conditions of copper working electrode in copper fluorosilicate solution are the best. Combining the above conditions, if copper fluorosilicate as the main salt of copper plating solution also need to find the right conditions so that the copper in the fluorosilicate copper system as a reversible system. So that the copper in the fluoride solution of copper silicate solution and the reduction of the balance.