Abstract: A magnesium oxide having a cubic system needle-like crystal structure and a length-to-diameter ratio, determined by an electron microscope at a magnification of 10,000, of at least about 5; and a process for producing a magnesium oxide having a cubic system needle-like crystal structure, which comprises calcining a basic magnesium compound having a needle-like crystal structure expressed by the following formulaMg(OH).sub.2-nx A.sub.x.sup.n-.mH.sub.2 Owherein A.sup.n- represents a monovalent (n=1) to tetravalent (n=4) anion, x is 0.2.ltoreq.x.ltoreq.0.5, and m is 0<m.ltoreq.2,or a magnesium hydroxide having a needle-like crystal structure, at a temperature of not less than about 400.degree. C. to convert it to the magnesium oxide.

Abstract: The invention relates to a process for the production of sintered magnesite from magnesium hydroxide in which filter cake is size reduced in a stream of hot air to a certain particle size, after which the material is heated and calcined and the dehydrated powder thus obtained is hot briquetted and introduced hot into the sintering zone. This process is distinguished by its high economy on heat and by the production of a readily sinterable dehydrated powder.

Abstract: There is provided a process for replacing the magnesium oxide portion of a nature magnesium silicate with sodium oxide thereby to form sodium silicate which comprises melting a natural magnesium silicate and sodium carbonate at a temperature of from 1100.degree. to 1350.degree. C. until a clear melt is obtained, the molar ratio of sodium oxide derived from the sodium carbonate per mole of silica contained in the natural magnesium silicate being from 4:1 to 7:1, quenching and extracting said clear melt with water and separating the insoluble magnesium oxide from the solution containing predominantly sodium silicate and sodium hydroxide.

Abstract: Slaked lime (calcium hydroxide) is obtained by contacting quicklime (calcium oxide) with an aqueous solution containing at least one anion selected from the group consisting of Cl, Br and NO.sub.3 ions in a concentration of about 0.1 to about 5 mole/liter at a temperature of about 10.degree. C. to about 65.degree. C. Magnesium hydroxide can be produced by reacting the aforesaid slaked lime with magnesium chloride or magnesium nitrate in an aqueous medium, the amount of slaked lime being about 0.5 to about 0.95 equivalent per equivalent of the magnesium compound, and thereafter heat-trating the reaction product in an aqueous medium at a temperature of about 150.degree. C. to about 250.degree. C.

Abstract: This invention relates to a method and apparatus for producing high pH water containing dissolved lime by forcing potable water through a column of powdered lime supported on a porous support without transporting significant quantities of lime out of the column. Two or more columns may be connected in parallel to permit recharging of one while the other remains on stream.

Abstract: A crystal having a high-quantum efficiency and a long period of luminescence is formed of an oxide selected from the group consisting of magnesium oxide and calcium oxide and possessing a concentration ratio of H.sup.- ions to F centers in the range of about 0.05 to about 10.

Abstract: A method for improving the density and other properties of caustic magnesia and sintered periclase. To improve the density of sintered periclase, acid or acid salt is admixed with magnesium hydroxide, followed by caustic-firing, pressing and high-firing. If desired, the admixture is dried before caustic-firing. Alternatively, the step of caustic-firing may be omitted. To improve the density and compactability of caustic magnesia, acid or acid salt is admixed with magnesium hydroxide, followed by caustic-firing. If desired, the admixture is dried before caustic-firing. Preferably, acetic acid is used.

Abstract: Biomass residue is added at the cold end of a rotary calcination kiln to generate heat in situ thereby diminishing substantially the amount of fossil fuel normally fired at the hot end of the kiln.

Abstract: Magnesium oxide, especially suitable for use in basic refractories, is produced from brine or bittern containing magnesium chloride by:(a) adding to the brine or bittern, as a source of MgO and/or CaO, MgO or Mg(OH).sub.2 or calcined magnesite or calcined dolomite or calcined calcite/limestone in such amount that in the case of MgO, Mg(OH).sub.2 or calcined magnesite, the molar ratio of MgO:MgCl.sub.2 is in the range of 1:1.5 to 1:15 (i.e. 0.66:1 to 0.066:1) or, in the case of calcined dolomite, the molar ratio of MgO+CaO:MgCl.sub.2 is in the range of 0.66:1 to 0.05:1, or, in the case of calcined calcite/limestone, the molar ratio of CaO:MgCl.sub.2 is in the range of 0.66:1 to 0.1:1;(b) keeping the mixture at a temperature below 90.degree. C. till a solid mass is formed; and(c) drying the said solid mass at a temperature up to 200.degree. C.The said mass may then be calcined at a maximum temperature of 1200.degree. C. and optionally then briquetted with a binder and fired at above 1400.degree. C.

Abstract: In a process of preparing sinter magnesia from magnesium oxide in a sintering kiln evolving flue gases during sintering, the flue gases are washed before their removal from the kiln to the atmosphere with a portion of the magnesium chloride slurry formed during the preparation of the magnesium oxide and the magnesium chloride slurry used for washing the flue gases is recycled to the slurry wherefrom the magnesium sol for making the magnesium oxide is derived.

Abstract: Hydrogen is produced by placing a magnesium electrode and another electrode in an electrolyte solution, applying a direct or an alternating current voltage between said electrodes for activating said magnesium electrode until the surface of the magnesium electrode turns blackish in color; then discontinuing said voltage and then generating hydrogen by placing the activated magnesium electrode in sea water or an aqueous solution of a neutral salt.

Abstract: A method for leaching magnesium from a magnesium hydroxide-containing composition, especially a mineral, which comprises contacting said composition with an aqueous solution of an ammonium salt whose corresponding magnesium salt is soluble in said aqueous solution to thereby produce said soluble magnesium salt; separating said aqueous solution from said composition; and transforming the magnesium of said soluble magnesium salt into an insoluble magnesium compound. The method is particularly useful for leaching magnesium from brucite-containing chrysotile asbestos fibers, to yield both a magnesium compound and brucite-free, dispersed chrysotile fibers.

Abstract: High density, dead burned refractory magnesia (MgO) is produced by sintering compacts formed by simultaneously thermally dehydrating and mechanically working an aqueous slurry of magnesium hydroxide.

Abstract: Disclosed is a process for producing and then rapidly recovering magnesium hydroxide from an aqueous liquid containing magnesium ion. The magnesium hydroxide is produced by treating the aqueous liquid with lime. The particles of magnesium hydroxide are then recovered from the liquid by causing rapid agglomeration and separation of the magnesium hydroxide particles.

Abstract: Hydrogen is produced by immersing a piece of magnesium in an electrolytic solution containing, for example, nickel, chromium, manganese, iron or platinum and then by immersing the magnesium piece in a neutral salt solution containing, for example, NaCl or KCl, or in sea water. Furthermore, hydrogen is produced by keeping a magnesium piece in contact with a metal, such as iron in the neutral salt solution for a certain period of time and then by replacing the magnesium piece in another neutral salt solution. In the latter method, the generation of hydrogen can be accelerated by connecting the magnesium piece and the metal to a direct-current supply in the range of 5 V to 200 V for a short time before the magnesium piece is immersed in the second neutral salt solution.

Abstract: Fibrous magnesium hydroxide having a hexagonal needle-like crystal structure. The fibrous magnesium hydroxide can be produced by drying a basic magnesium compound having a needle like crystal structure expressed by the following formulaMg(OH).sub.2-nx.A.sub.x.sup.n-.mH.sub.2 Owherein n is 1 or 2, A.sup.n- represents a monovalent or divalent anion, x is 0.2.ltoreq.x.ltoreq.0.5, and m is O<m.ltoreq.2,under conditions which do not cause a loss of its needle-like crystal form so that a part of the water of crystallization is liberated from the magnesium compound; and contacting the dried magnesium compound with an alkali in a liquid medium which is inert to the magnesium compound and does not dissolve the magnesium compound.

Abstract: High density, dead burned refractory magnesia (MgO) is produced by sintering compacts formed by simultaneously thermally dehydrating and mechanical working an aqueous slurry of magnesium hydroxide.

Abstract: This invention relates to stable, fluid magnesium-containing dispersions and the preparations thereof by the high temperature dehydration of Mg(OH).sub.2 to MgO in a dispersant-containing fluid.

Abstract: A process for the calcining of limestone or hydrated lime by thermal treatment thereof with hot gases in an oxidizing atmosphere in a rotary kiln through which the kiln atmosphere and the charge are countercurrently passed, which kiln is fed with fuel from shell burners, is described. The invention resides in the use of different fuels which release different quantities of SO.sub.2 and SO.sub.3 per unit of calorific heat. The fuel which releases the larger quantity of SO.sub.2 or SO.sub.3 per unit value of calorific heat is supplied to the upper portion of the rotary kiln, and the fuel which releases the smaller quantity of SO.sub.2 and SO.sub.3 per unit of calorific heat is supplied to the lower portion of the rotary kiln.

Abstract: A process for removing chlorine ions from wet flue-gas processing system.According to the process of this invention, the accumulation of the chlorine ions in the processing system is sufficiently prevented, and thus the corrosion of the apparatus is efficiently avoided.

Abstract: A process for treatment of aluminum chloride production offgas containing Cl.sub.2, CO, CO.sub.2, HCl, COCl.sub.2, COS, SO.sub.2, N.sub.2, SiCl.sub.4 and metal chlorides by reaction with water vapor in the presence of an alumina or low iron sand catalyst to convert SiCl.sub.4 and metal chlorides to the corresponding oxides and HCl; subsequent reaction of COCl.sub.2 with water vapor in the presence of an activated carbon catalyst to form CO.sub.2 and HCl; and removal of HCl by contacting the offgas with liquid water. Reaction with steam in the presence of alumina catalyst prior to reaction with steam in the presence of an activated carbon catalyst prolongs the useful life of the activated carbon catalyst and avoids the necessity of removing SiCl.sub.4 and metal chlorides from the offgas by adsorption onto dry activated carbon prior to contacting the activated carbon catalyst with offgas.

Abstract: The flowability of particulate lime is enhanced by treatment with effective amounts of selected fluid polymethylhydrogensiloxanes, polydimethylsiloxanes, and/or mixtures thereof.

Abstract: A novel ceramic form of hydroxylapatite and a novel ceramic product comprising a mixture of the latter and whitlockite, the preparation of these ceramics and dental restorative compositions and dental and surgical prosthetic materials containing the same are disclosed. Also described is a novel and improved process for producing polycrystalline ceramic oxides.

Abstract: A thermochemical process for producing hydrogen comprises the step of reacting CoO with BaO or Ba(OH).sub.2 in the presence of steam to produce H.sub.2 and novel double oxides of Ba and Co having the empirical formulas BaCoO.sub.2.33 and Ba.sub.2 CoO.sub.3.33. The double oxide can be reacted with H.sub.2 O to form Co.sub.3 O.sub.4 and Ba(OH).sub.2 which can be recycled to the original reaction. The Co.sub.3 O.sub.4 is converted to CoO by either of two procedures. In one embodiment Co.sub.3 O.sub.4 is heated, preferably in steam, to form CoO. In another embodiment Co.sub.3 O.sub.4 is reacted with aqueous HCl solution to produce CoCl.sub.2 and Cl.sub.2. The CoCl.sub.2 is reacted with H.sub.2 O to form CoO and HCl and the CoO is recycled to the initial reaction step. The Cl.sub.2 can be reacted with H.sub.2 O to produce HCl. HCl can be recycled for reaction with Co.sub.3 O.sub.4.

Abstract: This invention relates to stable, fluid magnesium-containing dispersions and the preparations thereof by the high temperature decomposition of Magnesium salts of carboxylic acids to MgO in a dispersant-containing fluid.

Abstract: An improved process for preparing active oxide powders in which cation hydroxide gels, prepared in the conventional manner are chemically dried by alternately washing the gels with a liquid organic compound having polar characteristics and a liquid organic compound having nonpolar characteristics until the mechanical water is removed from the gel. The water-free cation hydroxide is then contacted with a final liquid organic wash to remove the previous organic wash and speed drying. The dried hydroxide treated in the conventional manner will form a highly sinterable active oxide powder.

Abstract: A process for the production of magnesium oxide of moderate activity and high availability from a waste material containing dead-burned magnesium oxide of essentially no activity and lower availability (e.g., spent basic oxygen furnace firebrick) is disclosed. Spent basic oxygen furnace firebrick particles are calcined at a temperature of about 1000.degree. to about 2000.degree. F. for a time of from about 15 to about 60 minutes. The magnesium oxide in the spent, calcined firebrick is thus converted from dead-burned magnesium oxide to a magnesium oxide having a solubility of above about 90% in dilute hydrochloric acid and moderate activity in the nature of light-burned magnesium oxide. The color of the calcined magnesium oxide is also improved and the carbon content of the spent firebrick is essentially removed. The resulting product is generally useful in the same manner as conventional light-burned magnesium oxide.

Abstract: A method of making ferro-lime in a rotary lime kiln by feeding pellets containing iron into the kiln together with the stone to be processed. The pellets should be substantially dust free and strong enough to withstand the tumbling action of the kiln without disintegrating, and should be of a size and density compatible with the stone being fed to ensure proper mixing within the kiln. This invention is particularly adapted to the formation of ferro-lime or dolomitic ferro-lime.

Abstract: A process of producing calcium aluminate monosulfate hydrate by reacting a mixture of a lime component, an alumina component, a calcium sulfate component, and water at a temperature of from about 100.degree. C. to about 200.degree. C.By the process of this invention, the aimed product having a high purity is obtained at a high yield without need of high temperature for the reaction. The product obtained is useful as building materials.

Abstract: Granulated magnesium hydroxide is prepared by agglomerating finely divided magnesia with water as a binding agent to produce granules, the water serving to hydrate the magnesia. The magnesium hydroxide may be thermally decomposed to obtain magnesia of a large specific surface, such as microporous magnesia.

Abstract: The present invention relates to the production of chlorine and magnesium oxide. According to the process substantially anhydrous magnesium chloride, containing at least 95% MgCl.sub.2, is admixed with particulate magnesium oxide and contacted with gas comprising oxygen at a temperature from about 700.degree. C. to about 1100.degree. C. One of the advantages of the process according to the present invention is to utilize the exothermicity of the oxidation of the molten magnesium chloride, the reaction being self-sustained. According to a preferred embodiment, the particulate magnesium oxide is preheated at a temperature of above 720.degree. C. before it is admixed with the molten magnesium chloride and serves as the heat transfer agent for the subsequent oxidation of the magnesium chloride.The process may be carried out in a stack reactor or in a fluidized bed reactor. The oxidation is effected with substantially dry, pure oxygen or air.

Abstract: A process for removing boron contaminant from magnesium halide-containing brine wherein the brine is contacted with active magnesia to precipitate boron-containing magnesium hydrate and to remove at least 50%, and up to at least 95%, by weight of the total boron content of the untreated brine, without reduction of the magnesium halide content of said brine. The active magnesia is employed in an amount of from about 0.1% to about 10% by weight, preferably from about 2% to about 6% by weight, of the untreated brine, which may be heated e.g., from about 140.degree. F to the boiling point thereof, prior to contact with said active magnesia. Subsequently, the treated brine can be used, by reacting it with dolime, to form magnesium hydroxide which, in turn, can be calcined to produce MgO, each of which is a high-purity-low-boron product, i.e., less than 150 ppm boron on an oxide basis, and preferably less than 75 ppm. In addition, the MgO will contain less than 1.

Abstract: A process for making magnesia wherein a sludge of magnesium hydroxide is simultaneously dewatered and compacted to give a cake of magnesium hydroxide containing at least 67.5% by weight of solids and having a green bulk density of at least 1.15 grams/cc and wherein the cake thereby obtained is converted by a suitable heat treatment into magnesium oxide.Refractory products produced from the magnesia of the invention are also described.

Abstract: Metal values are extracted from manganiferous ocean floor nodule ore by treating the ore with hydrochloric acid, thereby producing chlorine and a starting pulp containing a solution of the metal chlorides and a solid residue. The starting pulp is subjected to at least two subsequent acidifications with HCl, each acidification being followed by addition of fresh ore, thereby producing chlorine and a final pulp containing a concentrated solution of metal chlorides and a solid residue. The solid residue is separated from the concentrated solution and substantially all the metal values, except manganese and alkali and alkaline earth metals, are separated from the solution. The manganese is separated from the solution by treatment with chlorine, at least the major portion of which was produced in the preceding leaching steps, while maintaining the solution at a pH of between about 3 and 7 by addition of a neutralizing agent such as MgO or Mg(OH).sub.2 whereby the manganese is precipitated in the form of MnO.sub.

Abstract: Pellet-shaped calcium hydroxide forming part of the mixture of flux and ores in electrothermal calcium carbide furnaces is calcined. The pellets are made by granulating or briquetting moist calcium hydroxide, delivered to a sintering grate and conveyed thereon through a heating zone, wherein high temperatures are produced by the combustion of gas, above the grate, and wherein the combustion gas is exhausted, below the grate. The calcium hydroxide pellets are more especially placed on to the grate, covered with a layer of broken limestone and the undried pellets are directly conveyed through the heating zone, in an apparatus for carrying out the process.

Abstract: Magnesia of very high purity is produced industrially from a magnesite waste material wherein impurities are present in such amounts that the weight ratio of the precipitable hydroxide ions, calculated as the sum of Fe.sub.2 O.sub.3 + Al.sub.2 O.sub.3 + Cr.sub.2 O.sub.3 + Mn.sub.3 O.sub.4 to the sum of SiO.sub.2 + TiO.sub.2 + B.sub.2 O.sub.3, is at least 1 : 3. The starting material is dissolved in hydrochloric acid of 15-32% concentration, the impurities are precipitated by adjusting the pH of the acidic solution to 4 - 9, and the purified magnesium chloride solution is thermally decomposed into magnesia and hydrochloric acid gas, the latter being recycled to form the hydrochloric acid of the stated concentration for dissolving the starting material.

Abstract: Caustic magnesia and magnesium hydroxide slurry are mixed together with sufficient energy in a counter-current high energy mixer to form pellets of various sizes during hydration of the caustic magnesia. The pellets may be used as formed or may be calcined to caustic magnesia or deadburned in a kiln to refractory periclase.

Abstract: Process for hydrogenolysis of an alkali metal or an alkaline earth metal salt of formic acid so as to produce methanol and a metal hydroxide corresponding to the formic acid salt wherein a catalyst of cobalt, rhenium, ruthenium, palladium, platinum or mixtures thereof is used.

Abstract: Alumina is reacted with magnesium chloride in accordance with the chemical reactionAl.sub.2 O.sub.3 + 3MgCl.sub.2 .fwdarw.3MgO + 2AlCl.sub.3In the presence of a mixed mass of inert solid contact material, such as a fluidized mass of magnesium oxide particles. The aluminum trichloride is recovered and is advantageously employed in the treatment of hydrocarbonaceous material, such as retorted shale oil, to improve the physical and/or chemical properties thereof. The substantially carbon and/or hydrocarbon free retorted aluminiferous oil shale is useful as the source of the alumina in the above chemical reaction.