4 results about "Sodium bifluoride" patented technology

The invention discloses a method for recovering HF (hydrogen fluoride) from hydrofluoric acid waste liquid obtained in an aromatic fluoride industrial synthesis process. According to the HF recovery method provided by the invention, sodium fluoride is taken as a carrier, excessive sodium fluoride reacts with hydrogen fluoride in the hydrofluoric acid waste liquid to generate sodium bifluoride, and HF is released through suction filtration, drying and thermal liberation. The HF is subjected to adsorption-desorption circulation through NaF, so that the purpose of recycling HF without discharging three wastes is achieved; meanwhile, the filtrate returns to the aromatic fluoride industrial synthesis process to be recycled as an absorbent of diazonium salt pyrolysis tail gas; the obtained sodium fluoride is recycled as an HF adsorbent, so that the effect of recycling multiple resources is achieved.

The application discloses a preparation method of sodium tetrafluoroborate and an electrolyte, and the preparation method comprises the following steps: S1, preparation of an ionic raw material solution: mixing a boron source compound and a sodium source compound according to a stoichiometric ratio to obtain a raw material mixture, and dissolving the raw material mixture to form the ionic raw material solution; S2, preparation of sodium tetrafluoroborate crude product: performing a hydrothermal reaction on the ionic raw material solution obtained in the step S1, crystallizing, and vacuum drying to obtain the sodium tetrafluoroborate crude product; S3, purification of sodium tetrafluoroborate: dissolving and filtering the sodium tetrafluoroborate crude product obtained in the step S2, and crystallizing to obtain the final sodium tetrafluoroborate; and the sodium source compound is sodium fluoride and / or sodium hydrogen fluoride. The preparation method of the sodium tetrafluoroborate has the characteristics of low safety risk, green environmental protection, high product yield and strong process operability.

The application provides a method for preparing sodium hexafluorophosphate for sodium batteries from sodium bifluoride, which comprises the following steps: taking electronic-grade sodium hydroxide and electronic-grade hydrofluoric acid as raw materials to generate an intermediate product sodium fluoride, and then reacting the intermediate product with phosphorus pentafluoride to obtain high-purity sodium hexafluorophosphate for sodium batteries. The particle size distribution and yield of sodium fluoride crystals are controlled by adjusting the stirring rate and cooling conditions, and then the purity and yield of sodium hexafluorophosphate are controlled, so that the purity of the finally obtained sodium hexafluorophosphate can reach more than 99.8%, the yield can reach more than 85%, the sodium hexafluorophosphate has the advantages of low cost and high yield, and is beneficial to industrialized production.

This invention discloses a method for preparing sodium difluorophosphate, comprising the following steps: reacting phosphorus pentachloride, phosphorus pentoxide, and sodium hydrogen fluoride as raw materials in an organic solvent; after the reaction, purging with inert gas, filtering, concentrating and crystallizing, washing, and drying to obtain sodium difluorophosphate. This method features low raw material cost, simple process, rapid reaction, few by-products, no water introduction, high product purity, and is environmentally friendly.