Abstract: An X-ray amorphous magnesium carbonate is disclosed that is characterized by a cumulative pore volume of pores with a diameter smaller than 10 nm of at least 0.018 cm3/g, and a specific surface areas of at least 60 m2/g. The X-ray amorphous magnesium carbonate is produced by reacting an inorganic magnesium compound with alcohol in a CO2 atmosphere. The X-ray amorphous magnesium carbonate can be a powder or a pellet and acts as a desiccant in, for example, production of food, chemicals or pharmaceuticals.

Abstract: In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to produce a carbonate of the metal formerly contained in the metal silicate of step (a).

Abstract: A method for preparing nanotubes by providing nanorods of a piezoelectric material having an asymmetric crystal structure and by further providing hydroxide ions to the nanorods to etch inner parts of the nanorods to form the nanotubes.

Abstract: Methods are provided for producing a composition comprising carbonates, wherein the methods comprise utilizing waste sources of metal oxides. An aqueous solution of divalent cations, some or all of which are derived from a waste source of metal oxides, may be contacted with CO2 and subjected to precipitation conditions to provide compositions comprising carbonates. In some embodiments, a combustion ash is the waste source of metal oxides for the aqueous solution containing divalent cations. In some embodiments, a combustion ash is used to provide a source of proton-removing agents, divalent cations, silica, metal oxides, or other desired constituents or a combination thereof.

Abstract: A method for preparing nanotubes by providing nanorods of a piezoelectric material having an asymmetric crystal structure and by further providing hydroxide ions to the nanorods to etch inner parts of the nanorods to form the nanotubes.

Abstract: Uses for a composition comprising a polymer derived from at least two monomers: acrylic-x and an alkylamine, wherein said polymer is modified to contain a functional group capable of scavenging one or more compositions containing one or more metals are disclosed. These polymers have many uses in various mediums, including wastewater systems.

Abstract: A continuous process for purification of brine contaminated with alkaline earth metals. The process comprises combining the brine with an aqueous solution containing at least one of an alkali metal hydroxide and an alkali metal carbonate with efficient mixing by a micro-mixing device.

Abstract: A method and apparatus for producing a calcium carbonate product formed of small <100 ?m sized separate calcium carbonate particles. Calcium hydroxide is fed through a disintegration and spraying apparatus (14), operating on the principle of a pin mill, into a gas which contains carbon dioxide for precipitating calcium carbonate particles and which is inside a precipitation reactor (10). The temperature in the precipitation reactor is maintained at <65° C.

Abstract: The process provides for the preparation of MgO from the reaction of magnesium salt and alkali/lime. The crude Mg(OH)2 is directly calcined and then treated with water to disintegrate the mass spontaneously to yield a slurry and dissolve away the soluble salts. This slurry is much easier to filter and wash than the original Mg(OH)2 slurry, which helps to speed up the purification operation and also conserve fresh water. Another important advantage of the present method is that even pasty or dough like reaction products that are processed using dough mixers and similar equipment can be worked up with ease. There is no compromise in the quality of MgO achieved in this manner.

Abstract: Method for industrial manufacture of pure MgCO3 comprising providing an olivine containing species of rock, to comminute the olivine containing species of rock to increase its surface, to contact the comminuted olivine containing species of rock with water and CO2. The process is conducted in at least two steps, namely a first step (R1) at a first pH where a dissolving reacting as represented the equation: Mg2SiO4(S)+4H+=2Mg2++SiO2(aq)+2H2O, takes place. Then a precipitation takes place in the second step (R2) at a higher pH as represented by the equations: Mg2++HCO3?=MgCO3(S)+H+, and Mg2++CO32?=MgCO3(S), the presence of HCO3? and H+ ions mainly provided by the reaction between CO2 and water.

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: This patent describes the use of barium sulfate as filler for thermosetting and thermoplastic plastics, elastomers, sealants, adhesives, fillers, varnishes, paints, paper, glass and as substrate for colored pigment formulations as well as for single-layer or multilayer coatings consisting of metal oxides, metal oxide mixtures and/or metal compounds, as a nucleus of crystallization for lead sulfate in the negative electrode paste of lead accumulators and as an X-ray contrast medium, the barium sulfate being produced by a continuous process wherein a barium salt solution and a sulfate solution are simultaneously and continuously brought together in equimolar quantities in a precipitating suspension at a temperature of 30 to 90° C., with constant stirring, the precipitating suspension is withdrawn continuously in a steady volume and the barium sulfate precipitate is filtered, washed and optionally dried, wherein the barium salt solution has a concentration of 0.1 to 0.

Abstract: A process for the preparation of platy PCC comprising the steps of providing a suspension of calcium hydroxide, carbonating the suspension of calcium hydroxide, adding a condensed phosphate to the suspension prior to the completion of carbonation to precipitate platy calcium carbonate. A paper that is filled is also provided and a paper that is coated and a polymer that is filled are envisioned that use the platy PCC according to the present invention.

Abstract: Process and apparatus for recovering magnesium from foundry sludge and cell bleed electrolytes includes structure and/or steps for: (i) dissolving, in a water slurry, soluble chloride compounds in the magnesium-containing material; (ii) acidifying the water slurry to between substantially pH 4 and substantially pH 6; (iii) further acidifying the water slurry to between substantially pH 1 and substantially pH 0, and providing a magnesium chloride solution; (iv) precipitating calcium from the magnesium chloride solution; (v) separating solids from the magnesium chloride solution; (vi) stripping SO2 from the magnesium chloride solution; and (vii) precipitating NaCl from the magnesium chloride solution to provide a concentrated magnesium chloride solution.

Abstract: A method for the manufacture of precipitated calcium carbonate from impure calcium oxide of improved color is disclosed. The method comprises admixing impure calcium oxide with an aqueous solution consisting essentially of a salt of at least one compound selected from the group consisting of organic amines of the formula RNH.sub.2 and alkanolamines of the formula NH.sub.2 (R.sup.1 OH), where R and R.sup.1 are alkyl groups of 1-4 carbon atoms, and hydrochloric or nitric acid. The solution obtained is treated with a reducing agent e.g. sodium hydrosulphite, separated from insoluble matter and then treated with carbon dioxide or the carbonate of the amine or alkanolamine at a temperature of at least 50.degree. C. Preferably, the amine of the salt and of the carbonate are the same, and the salt is used in at least the stoichiometric amount to dissolve the lime.

Abstract: A method of preparing precipitated calcium carbonate which comprises slaking quicklime in an aqueous medium, passing the suspension of calcium hydroxide through a sieve having an aperture size in the range of 40 to 70 microns, carbonating the calcium hydroxide and separating the calcium carbonate from the aqueous medium in which it is suspended. The sieved calcium hydroxide is subjected to high energy, high shear agitation which is terminated prior to carbonation. During the carbonation, the suspension of calcium hydroxide is subjected to relatively lower energy and shear agitation compared to the previous high energy, high shear agitation.

Abstract: A method for separating barium contaminants from soluble strontium compounds comprising adding sulfuric acid and a basic strontium compound in solid, suspended or dissolved form to an aqueous solution of a barium-contaminated soluble strontium compound in controlled amounts with thorough stirring to maintain the pH of the solution between about 3 and about 10; removing solids which precipitate from the solution; and thereafter recovering a strontium compound having a decreased barium content from the solution. The method may be carried out continuously or batch-wise, and the sulfuric acid and basic strontium compound can be added in repeated alternating portions or continuously.

Abstract: A method of substantially removing a trace metallic contaminant from a liquid containing the same comprises,adding an oxidizing agent to a liquid containing a trace amount of a metallic contaminant of a concentration of up to about 10.sup.-1 ppm, the oxidizing agent being one which oxidizes the contaminant to form an oxidized product which is insoluble in the liquid and precipitates therefrom, and the conditions of the addition being selected to ensure that the precipitation of the oxidized product is homogeneous, andseparating the homogeneously precipitated product from the liquid.

Abstract: A method of separating magnesium from wet process superphosphoric acid by filtration characterized by no or minimizing agitation during the crystallization of the magnesium in order to form readily filterable agglomerates of MgH.sub.2 P.sub.2 O.sub.7.

Abstract: A process for obtaining calcium fluoride from the pond water of phosphoric acid plants and recycling the high phosphate defluorinated water to the pond is disclosed. Sufficient calcium carbonate is added to a solution having a pH of about 0.8, containing about 1% fluoride, 1% phosphate and less than 0.4% sulfate, to raise the pH thereof to 2-3, whereby calcium fluoride is precipitated as a major component, calcium phosphates and calcium sulfates are precipitated as minor components. The calcium fluoride precipitate obtained is washed with raw pond water to reduce the phosphate content and with ammonium carbonate solution to reduce the sulfate content. In this manner an industrially useful fluorspar is obtained. The low fluoride supernatant liquid is then mixed with sufficient raw pond water to bring the pH into the range 1.5-2.0 and the resulting suspension is then held in a lagoon for 5-21 days to permit separation of silica.

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: Sulfate solutions containing at least one valuable metal from the group: Fe, Ni and Co, particularly solutions resulting from the leaching of lateritic ores or concentrates, are treated to recover the valuable metal. The latter is precipitated by treating the solution with magnesium hydroxide. The resulting magnesium-containing solution is treated with lime under controlled conditions to precipitate relatively fine particles of magnesium hydroxide and relatively coarse particles of gypsum. The difference in particle size is relied on to separate the magnesium hydroxide (for recycling) from the gypsum (which is calcined to regenerate lime).

Abstract: A gelling agent is added to a brine containing magnesium chloride to convert the brine into a gel which is spray dried to produce dried magnesium chloride comprising substantially solid discrete particles of magnesium chloride having bulk densities in the range from about 12 to 45 pounds per cubic foot.

Abstract: This invention relates to a process for the treatment of the reaction mass produced during the joint elimination of barium-containing nitrite-/nitrate-bearing carburizing salt wastes and cyanide-/cyanate-bearing wastes by ignition of the dry mixture at elevated temperatures, comprising suspending the reaction mass in water and eitherA. neutralizing the alkaline suspension obtained with concentrated nitric acid to a pH value of 6, the feed velocity of the acid and conditions of agitation being so selected that the pH value of the suspension will at no time fall below pH 6, and separating the barium carbonate,OrB. freeing the alkaline suspension obtained from barium carbonate, and neutralizing the filtrate with concentrated nitric acid to a pH value of 7.2, the feed velocity of the acid and conditions of agitation being so selected that the pH value of the suspension will at no time fall below pH 7.