Abstract: A method of dehydrating carnallite, residing in that preliminarily enriched carnallite with 39-41 wt. % water is heated up to 205.degree.-230.degree. C. by fuel combustion products having a temperature of 500.degree.-600.degree. C., and a partially dehydrated carnallite with 3-8 wt. % water is obtained. Said dehydrated carnallite is melted in a reaction zone and the melt is subjected to the action of a chlorinating agent. Thereafter the melted carnallite is allowed to settle from solid impurities and, as a result, dehydrated carnallite is obtained with water content less than 0.5 wt. %. The melting of partially dehydrated carnallite with 3-8 wt. % water is performed with the aid of fuel combustion products having a temperature of 700.degree.-1150.degree. C. These products are introduced tangentially to the surface defining the reaction zone at a rate ensuring the formation of an intensive eddy flow of gases, which occupies the whole volume of the reaction zone.

Abstract: A process for removing a phosphorus component from fluorite containing such phosphorus component, which process comprises adding powder of the fluorite to an aqueous acid solution having an acid concentration of from 1.0 to 20 Wt% in an inorganic acid/phosphorus ratio of above 25:1 by mole to give a slurry, agitating the slurry at a temperature below 50.degree. C., and collecting the powder from the slurry. The mother liquor obtained after separation of the powder from the slurry may be recycled to the first step.

Abstract: Calcium fluoride is produced from pond waters resulting from phosphoric acid processing by treating the pond waters with calcium carbonate and/or calcium oxide in two stages to precipitate out the major part of the fluorine values from the waters as calcium fluoride. After removal of the calcium fluoride the filtrate is treated with calcium oxide to remove a substantial portion of the remaining fluorine values as calcium fluoride. After removal of these calcium fluoride solids, the filtrate is treated with another charge of calcium oxide to produce dicalcium phosphate (dical) which is separated from the aqueous phase. The aqueous phase is treated with an additional charge of calcium oxide to remove a substantial portion of the solids from the aqueous phase leaving waters that can be discharged as waste or recycled as process water.

Abstract: Fluorite ores and concentrates commonly contain sulphur as an impurity usually as the sulphate. This sulphur can be largely removed by heating the ore or a concentrate under reducing conditions.In the preferred process the ore or a concentrate is pelletized with carbon, heated to a temperature up to 900.degree. C. in a neutral atmosphere which is conveniently nitrogen or carbon dioxide or a mixture thereof.

Abstract: A process for purifying organically polluted salts comprising forming a melt of said salts at a temperature of from about 600.degree.to 1000.degree. C., and contacting salt melt with an oxygen-containing gas. Acidic or basic fluxes may be present. The heat to maintain the mass molten may be supplied by electrodes which dip into the melt and which may be hollow so oxygen can be introduced therethrough. A suitable apparatus is also described.

Abstract: A method of producing magnesium and chlorine including the steps of injecting concentrated magnesium chloride containing brine into a hot gas spray drier wherein most of the water is evaporated to produce cell feed in the form of a powder of high porosity discrete particles of impure MgCl.sub.2, the impure particles being purified by in situ reaction within an electrolytic cell by depositing the particles onto an area of the surface of molten electrolyte whereby a portion of the entrained impurities are vaporized and withdrawn and circulating the electrolyte through the interelectrode space where the remaining impurities are chlorinated by chlorine gas produced at the anode, the circulation being at a rate to entrain most of the magnesium oxide particles in suspension for reaction with chlorine gas generated at the anode element. The molten magnesium produced at the cathode is withdrawn in the usual manner.

Abstract: Carnallite, comprising principally of MgCl.sub.2. KCl.6H.sub.2 O, with varying amounts of sodium chloride and other impurities, is dissolved in a lower saturated monohydric aliphatic alcohol having from one to four carbon atoms such as methanol, ethanol, propanol, isopropyl alcohol, N-butyl alcohol, secondary-butyl alcohol, iso-butyl alcohol, and tert-butyl alcohol, to dissolve the magnesium chloride therein leaving an insoluble residue of principally potassium chloride, sodium chloride and other materials. The residue is filtered from the solution, dried and stored or further processed. The filtrate, a magnesium chloride hydrate solution is further processed by injecting steam or water into the solution and removing, e.g., evaporating the methanol from the solution leaving an aqueous magnesium chloride hexahydrate brine. The recovered methanol is dried by distillation, condensed and recycled.

Abstract: Magnesium metal is produced by electrolysis of a molten magnesium chloride electrolyte containing fluoride ions, the electrolyte being derived from holding pond brines which are partially deboronated, concentrated, gelled and spray dried in the presence of hydrochloric acid gas to form discrete particles of high density anhydrous magnesium chloride feed material for electrolytic cells.

Abstract: Minute amounts of boron present in naturally occurring brines found in oceans, inland seas, salt lakes and the like are removed by treating the brine with a solid, finely divided lignite.

Abstract: Spray-dried magnesium chloride salt containing minor amounts of impurities in the form of oxygen containing compounds including metal oxides and in particular particulate magnesium oxide, hydroxyl groups, and the like, is purified by forming a molten bath of said magnesium chloride salt and chlorinating the molten salt in the presence of carbon and an iron chloride complex.

Abstract: An arsenic sulfide mineral impurity, such as gersdoffite, is removed from talc by an oxidative leach treatment at a pH below 2.