Abstract: Applying a sufficient quantity of an Alkali metal or an Alkaline earth metal to a fluid in a stripping process loop 106 to form a first intermediary compound and thereby, to strip the undesired element from the process fluid 102. The first intermediary compound 130 is processed in a recovery process loop 110 to recover the Alkali metal or Alkaline earth metal. The recovered Alkali metal or Alkaline earth metal is then re-introduced to an additional quantity of process fluid to strip and clean the undesired element from the additional quantity of the process fluid. A recovery process loop 110 may include either or both of a chemical substitution process, and an electrolytic process, effective to separate the Alkali metal or Alkaline earth metal from the undesired element or another compound.

Abstract: Spray drying processes are used to form pharmaceutical compositions comprising a solid amorphous dispersion of a drug and a polymer.

Abstract: An aspect of the present invention is a preparation of a magnesium halide support for using as a composition of a catalyst in an olefin polymerization, wherein the magnesium halide support is a solid substance prepared by an aliphatic alcohol non-ionic surfactant, preferably is ethoxylated aliphatic alcohol. Another aspect of the present invention is a method for the preparation of the magnesium halide support for using as the composition of the catalyst in the olefin polymerization comprising the following steps: (a) adding a magnesium halide compound into an organic solvent, and heating; (b) cooling down the mixture from (a) rapidly to the room temperature or lower in the inert organic solvent and the aliphatic alcohol non-ionic surfactant; and (c) washing the magnesium halide with the anhydrous inert organic solvent, and drying, wherein the aliphatic alcohol non-ionic surfactant is ethoxylated aliphatic alcohol.

Abstract: Disclosed are compositions and methods useful for the rapid and facile simultaneous detection of malodorous bacterial metabolites in samples of expired breath and other fluids. The invention enables estimation, by simple visual inspection and comparison against standards, of the concentration of polyamines and volatile sulfur compounds in the micromolar to millimolar range.

Abstract: The method which is the subject of protection is characteristic by the fact that firstly is made the suspension consisting of 10 to 20 mass % of mineral talc and 80 to 90 mass % of water; resulting suspension is homogenized and thereafter is heated to the temperature 50° to 70° C. To heated suspension is then added 37% hydrochloric acid in the amount of 1 to 6 mass % under continuous stirring. After reaching pH 3 to 5 and increasing the temperature up to 85° C., to the suspension is then added concentrated sulphuric acid in the amount of 1 to 5 mass %. The suspension is further maintained at the temperature up to 90° C., then it is chilled to the ambient temperature and thereafter is separated the sediment which is finally dried at the temperature 140° to 160° C. after washing with water and reaching pH 5 to 6.

Abstract: The present invention provides an improved process for the preparation of MgO of high purity >99% from salt bitterns via intermediate formation of Mg(OH)2 obtained from the reaction of MgCl2 and lime, albeit indirectly, i.e., MgCl2 is first reacted with NH3 in aqueous medium and the slurry is then filtered with ease. The resultant NH4Cl-containing filtrate is then treated with any lime, to regenerate NH3 while the lime itself gets transformed into CaCl2 that is used for desulphatation of bittern so as to recover carnallite and thereafter MgCl2 of desired quality required in the present invention. The crude Mg(OH)2 is dried and calcined directly to produce pure MgO, taking advantage of the fact that adhering impurities in the Mg(OH)2 either volatilize away or get transformed into the desired product, i.e., MgO.

Abstract: Systems are disclosed for making and using micro-porous particulates at least partially composed of metal sulfides, particularly alkaline earth metal and transition metal sulfides, as sorbents for removal of mercury from flue gas. Calcium sulfide micro-porous powders derived from the high temperature reduction of calcium sulfate and calcium sulfite are disclosed to be reactive substrates for a group of sorbents for adsorption of mercury from coal combustion flue gases produced by the utilities industry, as well as from natural gas and gaseous and liquid hydrocarbons. The sorbents are useful for cost-effectively adsorbing elemental mercury and oxidized mercury species such as mercuric chloride from flue gases, including those containing acid gases (e.g., SO.sub.2, NO and NO.sub.2, and HCl), over a wide range of temperatures.

Abstract: Described is a method as well as an apparatus for hydration of a particulate or pulverulent material containing CaO. The method is peculiar in that water is added in a quantity which will ensure that the partial pressure PH2O of the added water as a function of the temperature (° C.) is maintained within the interval defined by the formula (I), where PH2O is the partial pressure of water vapour in atm. and T is the temperature in ° C. Hereby is obtained that the material particles do not lump into agglomerates, and that the particles are hydrated evenly from the outside and inwards so that it is the active surface of the material particles which undergoes hydration in connection with partial hydration. This is due to the fact that the liquid water will not get into contact with the material particles since the water will appear in vapour form within the specified interval.

Abstract: Cerium oxide powder having carbonate groups and made of crystalline primary particles containing cerium oxide and having carbonate groups on the surface and in a region close to the surface, and having a BET surface area of from 25 to 150 m2/g, a mean diameter of from 5 to 50 nm, a carbonate concentration in the region close to the surface decreasing inwardly from the surface, a carbon content due to carbonate groups on the surface of from 5 to 50% by area, a carbon content due to carbonate groups at a depth of about 5 nm in a region close to the surface of from 0 to 30% by area, a content of cerium oxide calculated as CeO2 and based on the powder of at least 99.5% by weight and a content of organic and inorganic carbon of from 0.01 to 0.3% by weight. A dispersion containing this powder.

Abstract: A positive electrode active material for a lithium secondary battery according to an aspect of the present invention is a lithium-transition metal compound oxide which is produced by mixing a lithium compound, a transition metal compound, a magnesium compound, and a sulfate and conducting firing and which contains magnesium atoms and sulfate groups, wherein a magnesium halide is used as the magnesium compound.

Abstract: The present invention relates to recovery of industrial grade potassium chloride and low sodium edible salt from bittern as part of an integrated process. The process comprises, mixing low sulphate concentrated feed bittern (a by-product of salt industry) of density 31.5 to 32.5° Be (sp.gr. 1.277–1.289) with high density end bittern of density 36.5 to 37.5° Be? (sp.gr. 1.336–1.35), thereby producing low sodium carnallite, from which industrial grade potassium chloride is produced. The resultant bittern is evaporated in forced evaporation system, thereby producing crude carnallite, from which low sodium salt that would be beneficial to persons suffering from hypertension is produced. When sulphate-rich bittern is used, such bittern is desulphated with CaCl2 that is generated from carnallite decomposed liquor through reaction with lime, and wherein low B2O3-containing Mg(OH)2 is a by-product. The entire content of potassium in feed bittern is recovered in the process of the invention.

Abstract: A new process for recovery of common salt, potassium chloride, concentrated magnesium chloride with enriched bromide, and high purity magnesia from brine in an integrated manner, said process comprises preparation of calcium chloride by reaction of hydrochloric acid generated in the process with limestone, desulfatation of brine with calcium chloride, production of sodium chloride of superior quality in solar pans, solar evaporation of bittern thereby producing carnallite and end bittern, processing carnallite through established processes to produce potassium chloride, recovering end bittern containing highly concentrated magnesium chloride and enriched bromide and calcination of a part of the end bittern after solidification to produce high purity magnesia and hydrochloric acid utilizable in the process.

Abstract: The present invention provides a two stage process of thermal separation of CFCs and HCFCs followed by vitrification of the waste into a commercially viable glass. In the first stage, the hydrogenated compounds are reacted at elevated temperature with water and a metal oxide such as calcium oxide to form a halide salt and carbon dioxide. In the second stage of the process, the brine slag is reacted at elevated temperature with the carbon dioxide from stage one and glass-forming raw materials such as silicon dioxide to produce a glass. The final glass product incorporates the halide into the glass.

Abstract: A method of treating metal-contaminated spent foundry sand, or other industrial waste, by combining the sand with a sulfite to produce insoluble metal sulfur oxide complexes that do not leach from the sand. The treated waste may also be processed to reducing “clumping,” thereby rendering the treated waste appropriate for use in another industrial process.

Abstract: A process for the separation of heavy metal and halogen from unwanted waste material or residue. Halogen is selectively extracted or washed out from the waste material. Metal is selectively extracted or washed out from the essentially halogen free waste material.

Abstract: A method of treating metal-contaminated spent foundry sand, or other industrial waste, by combining the sand with a sulfite to produce insoluble metal sulfur oxide complexes that do not leach from the sand. The treated waste may also be processed to reduce “clumping,” thereby rendering the treated waste appropriate for use in another industrial process.

Abstract: The present invention relates to a process for treating fly ash/APC residues chlorides, sulphates, earth alkali metals selected from the group consisting of calcium, potassium, and sodium, and heavy metals selected from the group consisting of lead, which residues are obtained from air pollution control processes that utilize dry/semi-dry line injection, such that said residues may be disposed of as non-hazardous materials. The process comprises the sequential steps of: (a) washing and agitating the fly ash/APC residue (20) with water (50) to form a residue slurry containing solubilized lead salts and calcium chloride; (b) filtering (42) the residue slurry to remove a filtrate (46) having a pH of higher than about 11.8 and containing the solubilized lead salts and calcium chloride; and (c) recovering a first calcium enriched filter cake (44).

Abstract: The process for converting feed materials of high mineral content containing primary metal values and fluorine values to the primary metal or useful compounds thereof and to fluorine values or useful compounds thereof, wherein the feed materials constitutes a difficultly soluble matrix, the process having the steps of contacting the feed materials in a reactor with a humidified, gaseous system at from about 200.degree. C. to about 1600.degree. C., the contacting being carried out such as to convert the primary metal values to oxide residues at commercially acceptable rates and to evolve gaseous fluoride from the feed, digesting said oxide residues in an acidic digest medium and separating the primary metal values from the resulting digest liquor and from other components of the residues.

Abstract: Magnesium fluoride slag contaminated with metallic uranium or uranium compounds is treated by digestion with potassium hydroxide to soluble potassium fluoride and insoluble magnesium hydroxide. The solid and liquid phases are then separated and the solids phase is dissolved in acid to form a solution of metal salts. The liquid phase is treated with lime to precipitate calcium fluoride and convert the potassium back to potassium hydroxide for recycle to the digestion reaction. The metal salts are separated to remove the uranium salt from the magnesium salt. The result is an efficient removal of uranium contamination from the magnesium, the recovery of magnesium in a manner that permits efficient reuse or safe disposal, and the production of calcium fluoride useful for a variety of purposes.

Abstract: The process for converting feed materials of high mineral content and substantial radioactivity levels to concentrated radionuclide products of high radioactivity levels and to other products of discard or very low radioactivity levels, wherein the feed materials consists of a difficultly soluble matrix contain substantial metal, fluorine, and radionuclide values assaying above about 30 pCi/g, the process having the steps of contacting the feed materials with high temperature steam of from about 200.degree. C. to about 1500.degree. C.

Abstract: A process for removing alkaline earth metal impurities (e.g. calcium and magnesium ions) from an aqueous alkali metal chlorate solution which includes adding sufficient alkali metal carbonate or hydroxide or both to the impure solution to raise the pH to above 9 and form alkaline earth metal precipitates which are then removed from the pH-adjusted solution (e.g. by microfiltration). This process can lower the level of these impurities from about 1-20 ppm to less than about 0.3 ppm or less.

Abstract: Disclosed herein is a method for producing plasters that contain chloride contents of less than 0.5% by weight from calcium-containing impure products or residues having a high chloride content (e.g., about 10% or higher based on the total product or residue weight). The method does not require the addition of fly ash, SiO.sub.2 or Al.sub.2 O.sub.3. The method comprises temperature and water-mediated conversion of calcium chloride to calcium oxide in the calcium-containing product or residue using water, steam and/or substances that generate water to obtain calcium oxide and hydrochloric acid; and sulfating calcium components in the product or residue using oxygen and sulfur-containing, largely calcium-free substances. The product so obtained is an anhydride plaster which can optionally be hydrated.

Abstract: A process for working-up waste materials from barium sulfide or strontium sulfide leaching in which the amount of waste material to be disposed of is substantially decreased.

Abstract: A novel, solid-state, low-temperature preparation of barium sulfate provides a higher purity material than that obtained by the conventional method of precipitation. The reaction involves heating a barium oxysalt in the presence of at least one sulfur-containing species for a period of time.

Abstract: Process for production of magnesium chloride with sufficient purity for the production of magnesium metal, by leaching a magnesium containing raw material in hydrochloric acid. It is essential to keep the ratio between acid soluble iron and nickel greater than 120 and the ratio between acid soluble iron and phosphorus greater than 20 in the primary magnesium chloride solution, to obtain a sufficiently pure product. The acid soluble iron can partly or completely be substituted by an equal, molar amount of acid soluble aluminium. It is especially preferred to use mixtures of macro- and crypto-crystalline magnesites in the ratio 1:10-10:1 as raw material.

Abstract: A method and apparatus for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column is described. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water.

Abstract: In a process for the electrolytic production of magnesium by the molten salt electrolysis of magnesium chloride using a molten salt cell bath comprised mainly of one or more salts selected from alkali metal chlorides and alkaline earth metal chlorides, the molten salt bath is enriched with magnesium chloride by suspending a magnesium oxide and/or magnesium carbonate powder to form a molten suspension and passing a chlorine-containing gas through the molten suspension at a temperature of 600.degree.-900.degree. C. so as to react the suspended powder with chlorine to form magnesium chloride. The resulting molten salt enriched with magnesium chloride can be directly introduced into the cell for electrolysis, thereby eliminating moisture absorption by the highly hygroscopic magnesium chloride. A pure magnesium can be produced with a high yield and improved current efficiency.

Abstract: A method for production of sulfur dioxide from calcium sulfate by high temperature thermal reduction. Calcium sulfate, preferably in the form of calcined phosphogypsum, is desulfurized using a fossil fuel as a heat source, the combustion products resulting therefrom being used as a reductant. The fuel and reductant may be coal, coke, liquid hydrocarbons or natural gas; high sulfur, medium or low rank coal is preferred. The fuel is combusted with air or oxygen-enriched air. The solid feeds are introduced as finely-divided particles entrained in reactant gases, and the temperature is sufficiently hot to cause residual processed materials to melt and drain from the reaction vessel in the form of a liquid slag, yet not hot enough to produce significant amounts of fine silicon oxide dust. Iron pyrite, sand and/or clay can be added to reduce the slag melting point and to control its viscosity.

Abstract: Process for the production of anhydrous calcium fluosilicate from anhydrous calcium chloride and impure fluosilicic acid solution, a by-product of the acid treatment of phosphorus ores containing fluorine, characterized in that a calcium fluosilicate dihydrate is precipitated at low temperature and quantitatively by suitable adjustment of the fluosilicic acid concentration and the molar ratio CaCl.sub.2 /H.sub.2 SiF.sub.6 and that after filtration, washing and drying of the precipitate, an anhydrous calcium fluosilicate which can be easily decomposed by heat treatment is obtained to restore calcium fluoride and silicon tetrafluoride suitable for the manufacture of pure hydrofluoric acid and fluosilicic acid.For gravimetric concentrations of H.sub.2 SiF.sub.6 >25% and molar concentration ratios CaCl.sub.2 /H.sub.2 SiF.sub.6 between 2 and 5, the yields of the anhydrous calcium fluosilicate obtained are greater than 94%.

Abstract: A process for obtaining available elements from seawater is described, which process includes two separation steps. The first separation step involved adjusting the pH of seawater to a low pH by adding a strong acid having sulphate ion, adding a strongly alkaline agent thereto in amount sufficient to provide a high pH and separating the precipitate formed thereby from the filtrate. The second separation step involves concentrating the filtrate, cooling the concentrated filtrate and separating a precipitate thereby formed. Each precipitate and each filtrate obtained in these steps has characteristic components and can be utilized for many purposes, for example, for food additives, as a solvent for paint, as combustion aids, or as alkaline agents for neutralization etc.

Abstract: A pelletized mixture of gypsum, carbonaceous material and pyrite is charged to a travelling grate where the charge is heated under suitable conditions to produce a solid sintered material which has a broad spectrum of applications due to its chemical and physical properties and a gaseous effluent containing sulfur dioxide, sulfur or mixtures thereof.

Abstract: A method of obtaining magnesium fluoride substantially free from radioactive uranium from a slag containing the same and having a radioactivity level of at least about 7000 pCi/gm. The slag is ground to a particle size of about 200 microns or less. The ground slag is contacted with an acid under certain prescribed conditions to produce a liquid product and a particulate solid product. The particulate solid product is separated from the liquid and treated at least two more times with acid to produce a solid residue consisting essentially of magnesium fluoride substantially free of uranium and having a residual radioactivity level of less than about 1000 pCi/gm. In accordance with a particularly preferred embodiment of the invention a catalyst and an oxidizing agent are used during the acid treatment and preferably the acid is sulfuric acid having a strength of about 1.0 Normal.

Abstract: A reaction product of at least one of magnesium carbonate and magnesium silicate, with a metal chloride at a temperature exceeding 300.degree. C. Such a product, when mixed with water, sets to be an immensely strong magnesium cement. It may have aggregates of various types mixed with it.

Abstract: This disclosure involves a process for treating wet phospho-gypsum, a by-product from wet phosphoric acid manufacture, to remove fluorine values so as to make the sulfur values in the phospho-gypsum usable in making sulfuric acid in a contact sulfuric acid plant. The process involves drying the phospho-gypsum at 400.degree.-600.degree. C. to vaporize the fluorine values, the P.sub.2 O.sub.5 values and water and reacting the hot vapors with lime or limestone to remove the fluorine values as fluorspar. The P.sub.2 O.sub.5 values are subsequently condensed and used in a phosphoric acid plant. The dry phospho-gypsum is heated to 1200.degree.-1250.degree. C. under reducing conditions to produce SO.sub.2 gas and siliceous lime. The SO.sub.2 is then passed through a lime or limestone scrubber to eliminate any remaining fluorine values, dried and utilized in a contact sulfuric acid plant.

Abstract: A process for the recovery of sulfur from sulfur-bearing ores employing an aqueous leaching solution containing calcium monosulfide, calcium hydrosulfide or mixtures of such calcium sulfide species. The sulfur ore is contacted in an extraction zone with the aqueous leaching solution under conditions to solubilize sulfur from the ore in the form of calcium polysulfide. Preferably, the extraction step is carried out at an elevated temperature. The loaded leaching solution is recovered from the extraction zone and applied to a sulfur-production zone. Here the loaded solution is contacted with hydrogen sulfide under conditions to react the hydrogen sulfide with the calcium polysulfide to produce calcium hydrosulfide and elemental sulfur. The calcium hydrosulfide solution is recycled for use as leaching solution in the sulfur extraction zone.

Abstract: Spent flux containing calcium oxide and calcium sulfide, recovered from the reduction of iron ore, is carbonated, as an aqueous slurry, in two stages, with the first stage being operated at a pH to prevent reaction of calcium sulfide, and the second stage being operated at a pH at which calcium sulfide is reacted to produce an effluent gas containing hydrogen sulfide.

Abstract: This disclosure concerns an improved phospho-gypsum recovery process in which phospho-gypsum waste product and coke are first heated to remove moisture, some SO.sub.2 and other vaporous matter, then heated to a higher temperature in a reducing atmosphere to remove and separately recover SO.sub.2, then further heated in an oxidizing atmosphere to about 1200.degree. to 1250.degree. C. to remove any unreacted carbon and calcium sulfide before entering an electric furnace. The disclosure also concerns passing the gas stream from the condenser-heat exchanger over the clinker from the electric furnace to scrub SO.sub.2 from said gas stream. The essence of the invention is the unique absorber system used to remove any and all remaining fluorine in the gases from the calciner/furnace. If not removed, the fluorine will severely harm the catalyst used in the contact sulfuric acid plant to which the gases are sent for recovery of sulfur values.

Abstract: Metal trithiocarbonates such as Na.sub.2 CS.sub.3 are useful depressant for such sulfided minerals as copper and iron sulfides in molybdenum recovery.

Abstract: A method is described for decontaminating magnesium fluoride resulting from the reduction of uranium fluoride to the metal by reaction with magnesium. This decontamination employs reactions with magnesium and carbon to remove radioactive components from the said magnesium fluoride in its molten state.

Abstract: In electrolytic production of magnesium metal the concentration of magnesium chloride in the bath is required to be replenished periodically or continuously. This magnesium chloride should be anhydrous and of certain specifications.This invention provides a method for the production of such anhydrous magnesium chloride in a two-stage dehydration of magnesium chloride solution, the first step consisting of preparation of a fine powder from magnesium chloride with 0.5 to 1.5 molecules of water and about 4 to 10% magnesium oxide with or without alkali or alkaline earth metal chlorides, or both depending on the starting material. This first step is carried out in a conventional apparatus like the spray drier, briquetting the above partially dehydrated product in admixture with carbon powder under pressure to obtain compacted material such as briquettes of bulk density of 0.6 to 1.3 g/c.c., and size 1.5 to 5 cm. Second step comprises heating the above briquettes to a temperature of 200.degree. to 350.degree. C.

Abstract: Glycerine is recovered from an aqueous waste stream containing but minor amounts of glycerine by the requested steps of; (1) evaporating, (2) contacting with pentanol, (3) separating precipitated salt, (4) flashing to remove pentanol, and (5) vacuum distillation. This process is particularly useful treating saline waste water resulting from the manufacture of epoxy resins.

Abstract: An apparatus for chlorination of molten magnesium chloride salts, comprising a shell lined with a refractory material and having the interior thereof formed by walls, a bottom and a cover. The lower portion of the shell walls is provided with chlorine inlet means whereas the upper portion has a melt feed inlet means and a chlorinated melt outlet means. The interior of the shell is so tapered downward that its clear opening, F.sub.1, at the level of the chlorine inlet means is not over 0.3 times the clear opening, F.sub.2, at the level of the melt feed inlet means and the chlorinated melt outlet means.

Abstract: In a treatment of carnallitic ores by treatment with a decomposition-brine containing amounts of MgCl.sub.2, KCl and NaCl suitable for precipitating artificial sylvinite in a solution of MgCl.sub.2 saturated in KCl and NaCl, the improvement of adding to said decomposition-brine a collector, e.g., a fatty amine acetate, for the flotation of KCl and a source of gas, preferably a gas-liberating additive such as H.sub.2 O.sub.2, so as to contact newly formed crystal nucleii of KCl selectively with said collector and to contact bubbles of said gas with said collector so as to form a froth enriched in KCl simultaneously with the decomposition of said carnallite, the process being particularly useful for treatment of underground carnallitic ore whereby the froth and brine are withdrawn at the surface, separated, and the brine, after make-up additions, is recycled to the ore formation.

Abstract: Phosphogypsum is mixed with fine coal, balled, and charged to a travelling grate where the charge is heated under reducing conditions to evolve sulfur and/or sulfur dioxide for conversion into sulfuric acid.

Abstract: The invention relates to a process for the recovery of valuable metals from sulfidic, silicate-containing raw materials by slurrying the raw material in water, by subjecting the slurry to a selective leach under atmospheric conditions and in an acidic milieu, and by separating the valuable-metal containing solution from the solid leach residue.When the leach is carried out by introducing an oxygen-bearing gas into the slurry which contains finely-divided sulfide and carbon, the acidity of the slurry drops in a controlled manner so that a high efficiency of oxygen, and a high selectivity of the leach as regards valuable metals, are obtained. Owing to the presence of carbon the oxygen is reduced very easily and so oxygen efficiency is high and the rate of dissolving of the valuable metals increases in the slurry mixture.

Abstract: Treatment of waste water containing chlorides comprising treatment with Ca (OH).sub.2 or CaCO.sub.3 to convert the chlorides to CaCl.sub.2, adding sulfuric acid to said water in a reaction vessel to produce hydrochloric acid and gypsum, circulating the mixture in a closed cycle between the reaction vessel and a distillation column for the extractive distillation of the resulting hydrochloric acid, and filtering out the accumulating gypsum sludge from the treated waste water, wherein the added amount of waste water amount of hydrochloric acid correspond to the amount of sludge exiting the reaction vessel or the amount of distillate removed from the distilling column and the amount of gypsum separated, and the hydrochloric acid concentration in the liquid is less than the maximum azeotropic concentration for a mixture of H.sub.2 O and HCl.

Abstract: This disclosure concerns a process for treating phospho-gypsum waste product from the wet process method of making phosphoric acid including the steps of water washing the phospho-gypsum to remove all but an acceptable level of fluorine before the phospho-gypsum is calcined. The process allows the use of high sulfur coal for the production of steam if desired for use in the overall process. The process also allows for production of SO.sub.3 from part of the phospho-gypsum in an electric furnace to enrich the SO.sub.2 stream for making sulfuric acid.

Abstract: Method for producing purified and concentrated MgCl.sub.2 -brine by evaporation and crystallization from brines containing MgCl.sub.2, KCl, NaCl and MgSO.sub.4 involving recirculation of carnallite and part of the final product brine. The carnallite is recirculated to a decomposition step (1) into which the whole or part of the crude brine is also introduced while part of the final product brine is recycled to the evaporation step (2). The method results in a pure end product by a simple process comprising only one evaporation step and without any addition of chemicals.

Abstract: An improved process for the wet-acid process for manufacture of phosphoric acid with recovery of valuable co-products is provided. Phosphate rock is digested in a sulfuric acid/phosphoric acid mixture. Phosphoric acid is filtered from the digested rock, the gypsum thus formed, and sludge from the phosphoric acid, are second-stage acid treated, washed, and heated in a drier-calciner at 900.degree. to 1300.degree. C. Sulfur dioxide evolved from the gypsum and the fossil fuel is used to replenish the sulfuric acid. The hot impure lime remaining is fused in an electric furnace to form valuable calcium aluminum silicate products, which are then tapped, cooled, stored, and sold. The only waste products from the process are common, sulfur dioxide free combustion gases from the high sulfur content fossil fuel. Nearly 100% recovery of all phosphorus and fluorine values is claimed.

Abstract: Magnesium oxide is chlorinated in molten impure magnesium chlorine with chlorine gas by adding ferrous chloride to magnesium chloride brine, drying the brine, adding a mixture of calcined petroleum coke and charcoal to the dried brine, melting the product and chlorinating the formed melt. Ferrous chloride is added in amounts sufficient to provide from about 1.0% to 2.2% by weight of iron in the dried product. A highly reactive carbon source is added in amounts of from about 0.8 to 2.3% by weight and a carbon source that is less reactive than the highly reactive carbon source is added in amounts ranging from about 0.8 to 2.3% by weight of dried brine. Iron levels in the magnesium chloride melt may be adjusted upwardly by addition of a mixture of iron oxide and charcoal.A melt cell characterized by side entry electrodes disposed at angles from 40.degree. to 50.degree., an arched roof configuration, and an improved electrode refractory and ceramic sleeve construction is used to chlorinate the magnesium.