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.

Provided is a preparation method and use method of a material for deep purification of HF electronic gas. A metal fluoride-loaded activated carbon material AC/MFx.nH20 is prepared, and a mixed gas flow of carbonyl fluoride and high-purity nitrogen is used to deeply dehydrate the material to obtain the material for deep purification of HF electronic gas AC/MFx. This kind of material has fluoride that can form crystal water to form hydrated metal fluoride, and has strong water absorption properties. Moreover, the anhydrous fluoride and activated carbon do not have to face the problem of being corroded by HF, and the collapse of framework structure and the secondary pollution to HF from reaction products would not be caused. The material has the advantages of high purity and extremely low moisture content when being used for efficiently removing moisture in HF.

A universal chemical processor (UCP) including a reactor vessel with a main chamber, comprises inlets for feedstock, a fluidizing medium and reactants. The UCP further includes a reactive X-ray chemical processor (RXCP) having a large area hollow cylindrical cold cathode in the main chamber, a grid positioned concentrically with respect to the cathode, and an anode positioned concentrically with respect to the cathode and grid. In operation, when activated, the cathode of the RXCP emits electrodes onto the anode, which then emits X-rays into a radiation zone within the main chamber capable of ionizing feedstock and reactants, inducing chemical reactions, and sterilizing and decomposing organic materials within the radiation zone, and wherein, a fluidized bed is supported in the main chamber when the fluidizing medium and feedstock are supplied. The RXCP and the fluidized bed portions can be operated separately or in conjunction to achieve unanticipated results.

A universal chemical processor (UCP) including a reactor vessel with a main chamber, comprises inlets for feedstock, a fluidizing medium and reactants. The UCP further includes a reactive X-ray chemical processor (RXCP) having a large area hollow cylindrical cold cathode in the main chamber, a grid positioned concentrically with respect to the cathode, and an anode positioned concentrically with respect to the cathode and grid. In operation, when activated, the cathode of the RXCP emits electrodes onto the anode, which then emits X-rays into a radiation zone within the main chamber capable of ionizing feedstock and reactants, inducing chemical reactions, and sterilizing and decomposing organic materials within the radiation zone, and wherein, a fluidized bed is supported in the main chamber when the fluidizing medium and feedstock are supplied. The RXCP and the fluidized bed portions can be operated separately or in conjunction to achieve unanticipated results.

Reaction chamber and methods of extraction of metal compounds, specifically tools for uranium hexafluoride (UF.sub.6) conversion into uranium dioxide (UO.sub.2) ceramic powder (up to 5% enrichment of U.sup.235) by applying a method of reductive pyrohydrolysis. In one aspect, the reaction chamber is a shell with upper and lower heads, comprising upper filtration area, equipped with metalceramic filters, regenerating nitrogen, the first reaction zone for conversion of uranium hexafluoride into uranyl fluoride, the second reaction zone with gas-distribution grid for building up fluidization layer for reduction of uranyl fluoride to uranium dioxide with a nozzle of steam, and hydrogen and nitrogen supply. On the side walls of the first reaction zone of the reaction chamber shell there are two nozzles located symmetrically for uranium hexafluoride, hydrogen and water steam supply. The chamber is equipped with a device for discharge of powder.

A process for reducing the concentration of one or more arsenic-containing compounds in an aqueous solution comprising at least one fluoroacid, which process comprises: (i) contacting the aqueous solution with an oxidising agent to produce one or more Asv-containing compounds; and (ii) removal of precipitated arsenic-containing compounds; wherein the process comprises a step (iii) the addition of an aqueous alkali solution or slurry, which may take place after step (i) and before step (ii) or after step (ii).

Apparatus for converting Spent Pot Lining (SPL) into inert slag, aluminum fluoride and energy includes a plasma arc furnace such that the destruction of SPL occurs therein. The furnace generates an electric arc within the waste, which arc travels from an anode to a cathode and destroys the waste due to the arc's extreme temperature, thereby converting a mineral fraction of SPL into vitrified inert slag lying within a crucible of the furnace. The furnace gasifies the carbon content of the SPL and produces a well-balanced syngas. The gasification takes place due to the controlled intake of air and steam into the furnace. The gasification reaction liberates significant amount of energy. Steam captures this excess energy, to provide part of the oxygen requirement for gasification and to contribute to raise the syngas H2 content. Steam also contributes to converting some SPL fluorides (NaF and Al2F3) into hydrogen fluoride. The plasma SPL processing system is compact (occupying less area than some competitive methods of SPL treatment), can be installed in close proximity to the aluminium plant (minimizing transportation of SPL and AlF3), and requires only electricity as its energy source and thus no fossil fuels.

An azeotropic or quasi-azeotropic composition including hydrogen fluoride, Z-3,3,3-trifluoro-1-chloropropene and one or more (hydro)halocarbon compounds including 1 to 3 carbon atoms. The (hydro) halocarbon compounds are preferably selected among tetrachlorofluoropropanes, trichlorodifluoropropanes, dichlorotrifluoropropanes, chlorotetrafluoropropanes, pentafluoropropanes, dichlorodifluoropropenes, chlorotrifluoropropenes and tetrafluoropropenes. A process for producing a main (hydro)halocarbon compound, including the formation of a mixture of compounds including hydrogen fluoride, Z-3,3,3-trifluoro-1-chloropropene and one or more other (hydro)halocarbon compounds, distillation of this mixture making it possible to collect, firstly, an azeotropic composition, and, secondly, at least one of the compounds of the mixture.

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.

The invention relates to a process for producing free-flowing calcium fluoride particles from a diluted aqueous solution of hydrogen fluoride comprising the step of reacting the diluted aqueous solution of hydrogen fluoride with calcium carbonate particles at a temperature of less than 50° C. The invention further relates to the use of the free-flowing calcium fluoride particles for the manufacturing of anhydrous hydrogen fluoride.