Embodiments of the invention relate to a process for removing fluoride from a solution or suspension containing zinc, in particular a solution of zinc sulfate, a defluoridated solution of zinc sulfate obtainable by such a process, its use as well as processes for producing zinc and hydrogen fluoride or hydrofluoric acid. The process for removing fluoride comprises (i) providing a solution or suspension A containing zinc, wherein the solution or suspension A containing zinc further contains fluoride ions; (ii) adding a solution B containing a dissolved salt of a rare earth element to the solution or suspension A containing zinc, wherein a solid comprising a rare earth element fluoride and a solution C containing zinc are formed; and (iii) separating the solid from the solution C containing zinc, wherein the solution C containing zinc has a lower concentration of fluoride ions than the solution or suspension A containing zinc.

A method for preparing electronic grade inorganic acids includes: introducing alkali metal salts into a waste acid solution containing hydrofluoric acid, nitric acid and water to obtain hydrogen fluoride vapor, and a distillation residue mixture containing nitric acid, water and the alkali metal salts; subjecting the first distillation residue mixture to evaporation treatment, and then introducing an alkali earth metal nitrate salt into the resultant nitric acid/water mixture followed by distillation treatment so as to obtain nitric acid vapor; and removing mist droplets in the hydrogen fluoride and nitric acid vapor, followed by condensation treatment and concentration adjustment so as to obtain electronic grade hydrofluoric acid and nitric acid.

A method of recycling mixtures of hydrochloric and hydrofluoric acid. In particular, a method of recycling hydrofluoric acid and boron fluoride mixtures. A process for upgrading mixtures of fluoroboron compounds contaminated with chlorides as an aqueous solution of boron fluoride hydrates, including a step of vacuum distillation. Also, a method of producing gaseous boron trifluoride.

This invention provides a method for stably producing 2,3,3,3-tetrafluoropropene for a long period of time wherein unreacted materials are reused after distillation without liquid-liquid separation to suppress catalyst deactivation. The method for producing 2,3,3,3-tetrafluoropropene comprises the step of reacting 1233xf or like chloropropene with hydrogen fluoride in the presence of a catalyst, the step of subjecting the reaction mixture obtained in the above step to distillation to separate the mixture into a first stream comprising 2,3,3,3-tetrafluoropropene as a main component and a second stream comprising unreacted hydrogen fluoride and organic matter containing unreacted chloropropene as main components, and the step of recycling the second stream to the above reaction, the distillation being performed under conditions in which the unreacted hydrogen fluoride and the organic matter containing the unreacted chloropropene do not undergo liquid-liquid separation at a portion of a distillation column from which the second stream is withdrawn.

The present disclosure provides a novel azeotropic or azeotrope-like composition comprising hydrogen fluoride and 1,1,2-trifluoroethane (HFC-143), 1-chloro-2,2-difluoroethane (HCFC-142), or 1,2-dichloro-1-fluoroethane (HCFC-141); and a separation method using the composition.

An azeotropic or azeotrope-like composition comprising hydrogen fluoride and HFC-143. An azeotropic or azeotrope-like composition comprising hydrogen fluoride and HCFC-142. An azeotropic or azeotrope-like composition comprising hydrogen fluoride and HCFC-141. A separation method of a composition comprising hydrogen fluoride and at least one member selected from the group consisting of HFC-143, HCFC-142, and HCFC-141.

This disclosure provides a novel azeotrope-like composition and a separation method using the composition. The disclosure provides an azeotrope-like composition comprising 1,2-difluoroethylene (HFO-1132) and hydrogen fluoride; an azeotrope-like composition comprising 1,1,2-trifluoroethylene (HFO-1123) and hydrogen fluoride; and a separation method of a composition comprising hydrogen fluoride and at least one member selected from the group consisting of trans-1,2-difluoroethylene (HFO-1132(E)), cis-1,2-difluoroethylene (HFO-1132(Z)), and 1,1,2-trifluoroethylene (HFO-1123).

A process for treating an ammonium fluorosulfate byproduct includes providing an ammonium fluorosulfate byproduct including primarily ammonium fluorosulfate and lesser amounts of fluorosulfonic acid and bis(fluorosulfonyl) imide, mixing the ammonium fluorosulfate byproduct with water, reacting the mixture of the ammonium fluorosulfate byproduct and the water at a hydrolysis reaction temperature to hydrolyze the ammonium fluorosulfate, the fluorosulfonic acid and the bis(fluorosulfonyl) imide to form ammonium bisulfate and aqueous hydrogen fluoride; and separating the ammonium bisulfate from the aqueous hydrogen fluoride.

The present disclosure discloses a method for graded utilization of fluorine and silicon resources in a phosphate ore. While the phosphate ore reacts with sulfuric acid, a fluorine-containing and silicon-containing tail gas is produced. SiO.sub.2 and H.sub.2SiF.sub.6 solution with a high concentration are obtained by concentrating and filtering a solution containing HF and H.sub.2SiF.sub.6 formed after tail gas is absorbed by water. Crude SiF.sub.4 and a solution containing HF and H.sub.2SO.sub.4 are obtained by extracting, adsorbing, and dehydrating the H.sub.2SiF.sub.6 solution. SiF.sub.4 with a 5N purity is obtained after the crude SiF.sub.4 is adsorbed and distilled, at the same time, an impurity-enriched SiF.sub.4 is returned to operations of concentration and filtration to react with the solution containing HF and H.sub.2SiF.sub.6 to generate the H.sub.2SiF.sub.6 and SiO.sub.2. High-purity HF and waste sulfuric acid are obtained after the H.sub.2SO.sub.4 solution containing HF is separated by steam stripping and distillation.

A process for treating an ammonium fluorosulfate byproduct includes providing an ammonium fluorosulfate byproduct including primarily ammonium fluorosulfate and lesser amounts of fluorosulfonic acid and bis(fluorosulfonyl) imide, mixing the ammonium fluorosulfate byproduct with water, reacting the mixture of the ammonium fluorosulfate byproduct and the water at a hydrolysis reaction temperature to hydrolyze the ammonium fluorosulfate, the fluorosulfonic acid and the bis(fluorosulfonyl) imide to form ammonium bisulfate and aqueous hydrogen fluoride; and separating the ammonium bisulfate from the aqueous hydrogen fluoride.

Extraction of anhydrous hydrogen fluoride from its aqueous solution is provided. A method provides hydrogen fluoride from aqueous solutions, including the reduction of water component of the aqueous solution at an elevated temperature into carbon oxide, carbon dioxide and hydrogen. The condensation and distillation of the obtained hydrogen fluoride and water vapor are characterized by the fact that the mixture of hydrogen fluoride and water is reduced at a temperature of 800 K and above, the molar ratio of carbon to water in the reducing agent is from 0.5 to 4, and using a reducing agent of the general formula C.sub.nH.sub.mO.sub.k, where k≥0, m>0, and n>0, and the reducing agent may be saturated, unsaturated, aromatic hydrocarbons, oxygen-containing organic compounds, their isomers and their mixtures. The method makes it possible to extract hydrogen fluoride from its mixtures with water in any ratio and from azeotropic mixtures.