Abstract: Disclosed is a process for the preparation of calcium fluoride comprising reacting hexafluoro silicic acid with calcium carbonate in the presence of sulfate or aluminum ions within a pH range of between about 2 and 6 and separating the calcium fluoride precipitate from the resulting aqueous silica sol.

Abstract: Method and apparatus for directly desubliming gaseous aluminum chloride to solid form in a fluidized bed of solid particles of aluminum chloride at controlled temperatures for production of selectively constituted solid particulate aluminum chloride.

Abstract: Bromine is prepared by a method which comprises contacting hydrogen peroxide with an aqueous solution containing bromide ion and rapidly removing the bromine as it is formed. This method is particularly suitable for obtaining bromine from seawater, using the conventional intermediate, bromosulfuric solution.

Abstract: In the production of an ammonium fluoride solution by precipitating hexafluosilicic acid from its solution with ammonia and from the resulting suspension separating off the silicon dioxide precipitated, the improvement which comprises thoroughly mixing the hexafluosilicic acid solution and ammonia at a temperature of about 40.degree. to 90.degree. C, in such proportions that the suspension obtained contains at least 1% of free ammonia and at most 22% of ammonium fluoride, the average residence time of the reactants in the precipitation zone being at least 4 minutes. Advantageously, the silicon dioxide is separated off from the suspension obtained without previous cooling, the resulting ammonium fluoride filtrate is left standing for at least 30 minutes to permit flocculation of silicon dioxide contained therein and the flocculated silicon dioxide is separated off.

Abstract: Hydrogen is produced by the combustion of carbon with air to produce a combustion gas effluent containing carbon dioxide and nitrogen. The carbon dioxide is separated and reacted with carbon to produce carbon monoxide. The resulting produced carbon monoxide is then reacted with steam to produce carbon dioxide and hydrogen and the resulting produced hydrogen separated. The carbon utilized for the production of hydrogen may be obtained by the thermal decomposition of hydrocarbons to yield carbon and gaseous hydrogen or the carbon utilized in this process may be obtained from a solid carbonaceous fuel, such as coal or coke or the like.

Abstract: Anhydrous gold trichloride is prepared by stirring a suspension of finely divided tetrachloro-auric acid, having the thionyl chloride at a temperature in the range from 20.degree. to 65.degree. C in the absence of light, whereby said tetrachloro-auric acid and thionyl chloride react to form the desired end product.

Abstract: Silicoformic acid is reacted with an alkali metal cyanide, in a ratio of about 1 mol of the silicoformic acid to about 1 to 2 mols of the alkali metal cyanide to produce corresponding substituted silicoformic cyanides and dicyanides.

Abstract: This invention concerns a process for preparing metal and metal fluoride products. A molten mixture containing a metal oxide, a molten metal fluorinating agent and carbon is reacted to produce a gaseous oxide of carbon, a metal fluorinated product derived from the cation of the metal oxide, and a metal derived from the cation of the metal fluorinating agent.

Abstract: The invention relates to a process for the separation of zirconium, and hafnium tetrachlorides from mixtures thereof. The process according to the invention consists of selectively absorbing zirconium tetrachloride and hafnium tetrachloride vapors in a solvent medium circulating counter-current to these vapors in a distillation column, wherein the solvent consists of a molten chloroaluminate and/or chloroferrate of potassium. The process described may be used to obtain hafnium-free zirconium tetrachloride which may then be used to prepare nuclear-grade zirconium, and hafnium tetrachloride containing little zirconium.

Abstract: The invention concerns a method of purifying hydrogen chloride gas containing small quantities of chlorine. The purifying method comprises passing impure hydrogen chloride over carbon, at a temperature from 30.degree. to 200.degree. C, in the presence of at least one olefin, possibly containing chlorine. The method of the invention applies particularly to the hydrogen chloride obtained from a chloroethane cracking operation initiated by chlorine.

Abstract: Aluminum trichloride is separated and recovered from its complexes with hydrocarbons and hydrogen chloride by contacting the complexes with metallic aluminum at 20.degree.-100.degree. C and recovering the resulting precipitate of aluminum trichloride.

Abstract: Reactions in heterogeneous systems containing reactants in gaseous, liquid and solid phases are carried out in a tower composed of a series of superimposed reaction compartments mutually separated by horizontal shelves, through which the gaseous phase moves countercurrent to the liquid and solid phases and at the same time effects turbulent mixing with the liquid phase. The liquid and solid phases are introduced into the top compartment. The shelves are suitably perforated for upflow of the gas through bodies of mixed liquid and solids which are held on the shelves at levels determined by the heights of overflow pipes which conduct excess reaction mixture from each reaction compartment into the mixture in the compartment next below. Reaction products are taken off from the bottom compartment.

Abstract: A reduction/chlorination process is provided for the treatment of titaniferous materials such as ilmenite ores. The chlorination is selective in that the titanium constituent of the titaniferous material is chlorinated, but there is no appreciable net yield of iron chloride from the iron constituent. Where other metals such as vanadium are present they may be chlorinated with the titanium. The reduction utilizes as the reductant an amount of carbonaceous material which, based on oxygen in the titaniferous material, is at least stoichiometric to produce carbon monoxide. The selective chlorination utilizes as the chlorinating agent either ferrous chloride (FeCl.sub.2) alone or certain combinations of ferrous chloride and one or more other chlorine-containing members, notably molecular chlorine (Cl.sub.2) and hydrogen chloride (HCl). The use of ferric chloride (FeCl.sub.3) as a part or all of the chlorinating agent is the equivalent of using a FeCl.sub.2 /0.5 Cl.sub.2 mixture.

Abstract: Titanium tetrachloride is produced by reacting a titaniferous material having a particle size of 150 mesh or less (Tyler standard) as a median value with a chlorine-containing gas in the presence of a coarse carbonaceous substance in a dilute-phase fluidization system.

Abstract: A hot-pressed optical body is disclosed which is free from absorption bands due to carbon dioxide, water, hydroxyl ion and acid fluorides in the ultraviolet, visible and near-infrared wavelength regions. Typically, the optical body is formed from a powder of an alkaline earth metal fluoride, alkali metal fluoride, or rare earth metal fluoride. One or more absorption bands due to a single impurity may be reduced or eliminated, or bands due to plural impurities may be reduced or eliminated sequentially, or simultaneously. The optical body is made by flowing a reactive, reducing gas, optionally, in combination with hydrogen fluoride gas, directly into the die cavity containing a pressable powder, and either hot-pressing or extruding the powder.

Abstract: In the production of a solid-free solution of titanyl sulfate by digesting ilmenite or titanium slag with sulfuric acid, and filtering the resulting solid-containing solution of titanyl sulfate to separate the solids, the improvement which comprises filtering the solution under a pressure of about 1 to 16 bars to form a filter cake of a thickness of about 10 to 35 mm. The filter cake is washed with about 0.1 to 0.5 m.sup.3 of water per m.sup.3 of filtrate, the wash water is passed through the filter cake at a flow rate of about 0.1 to 1.2 m/h under a pressure of about 1 to 16 bars, and the filter cake is then squeezed to a solid content of about 50 to 70% by weight.

Abstract: This invention concerns a process for preparing metal and metal fluoride products. A molten mixture containing a metal oxide, a molten metal fluorinating agent and carbon is reacted to produce a gaseous oxide of carbon, a metal fluorinated product derived from the cation of the metal oxide, and a metal derived from the cation of the metal fluorinating agent.

Abstract: Preparation of titanium tetraperchlorate, vanadium perchlorate, and chromyl erchlorate by the reactions of chlorine perchlorate with the respective anhydrous metal chlorides at a temperature from about -45.degree. C to about 20.degree. C. These perchlorates are useful in compounding gas generating compositions.

Abstract: Hydrogen is produced from water by the addition of heat to a series of chemical reactions which comprise the reaction of cadmium with water, and the subsequent recovery of the cadmium for re-use. The equipment used to produce the hydrogen requires only the input of water and heat to produce an output of hydrogen and oxygen gas.

Abstract: Hypochlorite is produced by mixing chlorine and a strong alkali solution within a completely closed region filled with solution to eliminate the presence of any air pockets, thereby assuring that the gaseous chlorine will not escape from the solution during the mixing process. In carrying out the mixing step, the alkali solution and chlorine are introduced through relatively closely-spaced small streams into an enlarged chamber so that, effectively, mixing occurs by small amounts at the point of introduction of the two streams, instead of simply introducing a small amount of chlorine into a large volume of alkali solution. Mixing is further enhanced by the fact that the two streams are introduced tangentially into the chamber at diametrically opposed locations so that they swirl upwardly through the chamber in laminar flow relationship.