Abstract: Disclosed is a method for fast and cost-efficient preparation of ikaite crystals. The method comprises contacting an alkaline aqueous solution, which comprises carbonate and bicarbonate ions, with a water solution, which comprises Ca2+, at a temperature not exceeding 15° C., wherein contact between the alkaline aqueous solution and the water solution takes place at a permeable or porous surface, through which either solution is fed to the other at a flow rate facilitating formation of ikaite crystals. Also disclosed is system for carrying out the ikaite preparation process. The process and system provides a cost efficient and effective means for capture and storage of carbon dioxide.

Abstract: Coating compositions are disclosed that include corrosion resisting particles such that the coating composition can exhibit corrosion resistance properties. Also disclosed are substrates at least partially coated with a coating deposited from such a composition and multi-component composite coatings, wherein at least one coating later is deposited from such a coating composition. Methods and apparatus for making ultrafine solid particles are also disclosed.

Abstract: Disclosed is a device for scrubbing carbon dioxide-contaminated gas for use in a fuel cell. The device comprises at least one first opening for allowing gas to enter or exit the device, at least one second opening for allowing gas to exit or enter the device, and at least one sorbent that is capable of removing carbon dioxide from the gas and is arranged in a form of layers which the gas contacts when it flows from the first to the second opening. The device may further comprise one or two gas preparation units for removing solid and/or liquid contaminants from the gas and for adjusting the temperature and/or humidity of the gas.

Abstract: The invention features methods and systems for recovering carbon dioxide, for producing commercial quality carbon dioxide (CO2) of 90% to +99% purity using, wet calcium carbonate lime mud produced in a recausticizing process that also produces caustic soda, for instance, Kraft paper pulp mill lime mud (a.k.a., “lime mud”) as a feedstock to a multi-stage lime mud calcination process. This process may be fueled with low, or negative cost “carbon-neutral” fuels such as waste water treatment plant (WWTP) sludge, biomass, precipitated lignins, coal, or other low cost solid fuels. High reactivity, high-quality calcined lime mud (a.k.a. re-burned lime, or calcine), required in the Kraft paper pulp mill's recausticizing process is also produced, and superheated high pressure steam and hot boiler feed-water is generated and exported to the mill's steam distribution and generation system as well as hot process water for use in the mill's manufacturing operation.

Abstract: Provided herein are compositions, methods, and systems for a material containing metastable carbonate and stabilizer. Methods for making the compositions and using the compositions are also provided.

Abstract: The present invention provides a getter material comprising an adsorbent active substance with a specific surface area of 5˜40 m2/g. Also, the present invention provides a method for manufacturing the adsorbent active substance comprising the steps of: (a) selectively eluting cations by the acid processing of any one of calcium carbonate, barium carbonate, magnesium carbonate, aluminum carbonate, or strontium carbonate; (b) extracting the eluted cations; and (c) calcining any one of calcium carbonate, barium carbonate, magnesium carbonate, aluminum carbonate, or strontium carbonate from which cations have been extracted.

Abstract: A powder lime calcining process comprises: transporting fine granules of limestones having a water content less than 4%, and a granule size less than 15 mm, from a raw material storing bin to a small material bin, transporting the materials from the small material bin into an airflow pipe by a belt conveyer, heating and drying the materials, sieving the materials by a sieving device, transporting granules into a cyclone cylinder deduster and a clothbag deduster in turn by airflow pipes, the fine powders of limestones after dedusted are transported into an intermediate bin; the materials within the intermediate bin are transported to four preheating cyclone cylinders by a pneumatic lift pump and airflow pipes, and are preheated and separated; the materials after separated are transported into three cooling cyclone cylinders for cooling and separating the materials, finally transported into a finished product bin by a finished product transporting system.

Abstract: The system includes a first reactor configured to discharge CO2 depleted process gas. The first reactor having a first and a second portion of particulate sorbent material having captured CO2. A second reactor is arranged to receive the first portion of particulate sorbent material and is configured to release CO2 from the particulate sorbent material by decarbonation, return the first portion of particulate sorbent material to the first reactor, and discharge a CO2 rich gas stream. A third reactor is arranged to receive the second portion of particulate sorbent material and is configured to supply water to the second portion of particulate sorbent material to hydrate at least a part of a remaining portion of calcium oxide of the second portion of particulate sorbent material to form calcium hydroxide, and return the second portion of particulate sorbent material to the first reactor.

Abstract: Magnesium oxide powders having a large diameter of crystallite, and having a favorable crystallinity are provided. Magnesium oxide powders: having peak widths at half-height of the peaks on a (111) plane, a (200) plane and a (220) plane of each no greater than 0.20 degrees as determined with a powder X-ray diffraction method carried out using a Cu—K? ray; and having a crystallite diameter of no less than 700 ?.

Abstract: A recirculated-suspension pre-calciner system is disclosed, comprising: a vortex cyclone dust collecting equipment including a plurality of devices, wherein a top device of the vortex cyclone dust collecting equipment is used as a feed system; a vertical combustion kiln; a blower; and a powder purge system, wherein powders in the feed system fall into the vortex cyclone dust collecting equipment and pass through a plurality of the devices to mix and exchange heat with flue gas comprising CO2, generating calcination reaction and releasing CO2 into the flue gas. and the steam is separated and transported to the feed system by the blower and acts as a carrier gas of powders.

Abstract: This application concerns methods and apparatus for use in industrial waste recovery operations such as recovery of non-consumed chemicals in industrial processes, with recovery of quick lime in a wood pulp process being an example. In some embodiments, methods comprise baking lime sludge in a kiln and controlling a temperature in a calcining zone of the kiln to be above about 2250° F. to vaporize sodium contained in the lime sludge. Interaction of the vaporized sodium with SOx can deter accumulation of one or both of CaCO3 and CaSO4 on one or more inner surfaces of the kiln. In some embodiments, lime sludge can be rinsed to generate a filtrate comprising dissolved NaOH, and the filtrate can charge a scrubber for removing SOx from an exhaust from the kiln. Embodiments of co-fired burners for heating such kilns by burning petroleum coke and natural gas are also disclosed.

Abstract: A process for the separation of carbon dioxide from gas mixtures is disclosed in which a metal oxide sorbent, which is used to capture and release carbon dioxide, is recycled. The process incorporates the regeneration of the carbon dioxide capture capacity of the metal oxide to maintain a high capture capacity over many cycles. The regeneration involves hydrating the metal oxide and then heating the resulting metal hydroxide under a gas atmosphere that is effective to suppress the dehydration of the hydroxide so that dehydration occurs at an elevated temperature. The regeneration may also be used independently from the carbon dioxide separation process to produce, from a metal hydroxide, a metal oxide having an enhanced resistance to attrition and fragmentation.

Abstract: The present invention relates to a method for production of calcium compounds having very low content of phosphorus and boron from an impure calcium chloride, solution containing phosphorus and boron, which method comprises the following steps: a) addition of a FeCl3-solution to the calcium chloride solution, b) adjusting the pH of the solution by addition of a base to between 3 and 9.5 for precipitation of iron hydroxide, iron phosphate and boron compounds, c) removal of the solid precipitate from the solution in step b) obtaining a purified calcium chloride solution, d) precipitation of a calcium compound from the solution from step c), and e) separation of the calcium compound from the solution in step d).

Abstract: A method for manufacturing a cathode active material for a lithium rechargeable battery, including: selecting a first metal compound from a group consisting of a halide, a phosphate, a hydrogen phosphate and a sulfate of Mg or Al; selecting a second metal compound from a group consisting of an oxide, a hydroxide and a carbonate of Mg or Al; combining the first metal compound and the second metal compound to obtain a metal compound, the metal compound containing either Mg or Al atoms; mixing a lithium compound, a transition metal compound and the metal compound to obtain a mixture; and sintering the mixture.

Abstract: A method of manufacturing digestible powder that generates a hydride ion (H?) when dissolved in water is provided. A vacuum oven system that can reach 600° C. and 10?5 torr is used within this method. The method according to this current application comprises of ten to eleven steps of vacuuming, heating and hydrogen treatment of coral reef powder. By adding mixtures of magnesium, phosphorus and potassium, the maximum treating temperature and vacuum pressure is lowered. The coral reef powders treated via the ten steps emit hydrogen when dissolved in the water like powders that are treated with a mixture of natural form of magnesium, phosphorus and potassium complex. Those natural form of the magnesium, phosphorous and potassium includes (NH4)MgPO4.6H2O (struvite), MgSO4.KCl.H2O (Kainite), K2SO4.MgSO4.6H2O (Schönite), K2SO4.MgSO4.4H2O (Leonite), and K2SO4.2MgSO4 (Langbeinite).

Abstract: The invention provides various methods for removing gas phase pollutants by calcining limestone or dolomite using flash calcination to produce a high surface area lime or hydrated lime and directly adding the lime or hydrated lime to a gas stream containing gas phase pollutants. In other methods, the production of an activated sorbent, such as activated carbon, is combined with the production of the high surface area lime or hydrated lime and directly added to a gas stream containing gas phase pollutants. The combination of lime or hydrated lime and an activated sorbent enhances the removal of gas phase pollutants such as those from a coal-fired boiler flue gas.

Abstract: A method of manufacturing digestible powder that generates a hydride ion (H?) when dissolved in water is provided. A vacuum oven system that can reach 600° C. and 10?5 torr is used within this method. The method according to this current application comprises of ten to eleven steps of vacuuming, heating and hydrogen treatment of coral reef powder. By adding mixtures of magnesium, phosphorus and potassium, the maximum treating temperature and vacuum pressure is lowered. The coral reef powders treated via the ten steps emit hydrogen when dissolved in the water like powders that are treated with a mixture of natural form of magnesium, phosphorus and potassium complex. Those natural form of the magnesium, phosphorous and potassium includes (NH4)MgPO4.6H2O (struvite), MgSO4.KCl.H2O (Kainite), K2SO4.MgSO4.6H2O (Schonite), K2SO4.MgSO4.4H2O (Leonite), and K2SO4.2MgSO4 (Langbeinite).

Abstract: This invention refers to a novel process for obtaining high purity magnesium hydroxide from a solid starting material containing magnesium in the form of, and/or combined with, carbonates, oxides and/or hydroxides, either natural or synthetic. The process comprises leaching the starting material to dissolve the magnesium; the solution is treated with alkali to precipitate the high purity magnesium hydroxide, and the remaining mother liquor is fed to a regeneration step of both the alkali used in the precipitation of high purity magnesium hydroxide, and the acid for leaching. The process of the invention is characterized by recycling reactants (acid and alkali) regenerated in the same process.

Abstract: A method for regenerating a solid reactant includes streaming the solid reactant into an inlet port of a contact or vessel and heating the solid reactant inside the contactor vessel, streaming a purge oxidant into an oxidant port of the contactor vessel to reduce a partial pressure of gas released from the solid reactant, venting the gas from a gas port of the contactor vessel, and removing the solid reactant from a discharge port of the contactor vessel.

Abstract: A selective dispensing device (1) is disclosed for limestone in vats (5a, 5b) of a regenerating oven adapted to arrange limestone with greater sizes next to an external wall (7a, 7b) of the vats (5a, 5b) and limestone with smaller sizes next to an internal wall (8a, 8b) of the vats (5a, 5b), comprising at least one mobile bulkhead (11) connected to a drive shaft (13) rotating around a rotation axis (X), such rotation being driven by an actuator system and the mobile bulkhead (11) being able to rotate around the rotation axis X to be alternatively inclined by a first angle (?) and by a second angle (?) with respect to reference plane (Z).

Abstract: The present invention refers to a method to prepare nanometric magnesium hydroxide particles. These particles have an average diameter that ranges from 90 to 110 nm, and that could range from 20 to 160 nm, with monodisperse and stable characteristics for greater than 12 month in a wide range of concentrations. This process includes 3 stages: one reaction stage performed in two steps, one of maturation and one of purification. The first step of the reaction is developed in micro blending zone, and the second one is the stabilization of suspension. During the second stage, the particles maturation is developed through a chemical-mechanic treatment. The last stage is designed to purify and concentrate the material, as well as its preparation to integrate it to the desired form.

Abstract: Disclosed is a processes for the production of relatively high purity alkaline earth metal oxides, such as SrO, from relatively low purity forms of carbonated or other oxygenated forms of such metals, such as strontium carbonate. The relatively low purity material is exposed to conditions under which at least a portion of the metal contained therein is converted to a salt that is more readily solvated in a provided solvent than the starting material, while at the same time not substantially increasing the solubility of at least one or more of the impurities in such selected solvent. This step is then preferably followed by removal of solid or otherwise un-dissolved impurities from the solution. After the removal step, the solution is preferably exposed to conditions effective to form a relatively insoluble salt of the alkaline earth metal, such as a strontium salt. The insoluble salt is also preferably one that can be readily and effectively converted to the desired alkaline earth metal oxide, preferably SrO.

Abstract: A calcining system includes a calcining chamber of a sufficient length to effect a desired level of calcination of solid particles. A hot gas source to communicate hot gases within the calcining chamber. An entrainment gas source operable to communicate an entrainment gas to transport the solid particles into the calcining chamber to calcine the solid particles to form calcined solid particles.

Abstract: A method for feeding lime mud into a lime kiln including a rotary kiln shell having an interior between a first end wall and a second end wall, the method including: feeding the lime mud into a flue gas flow in the interior of the rotary kiln shell or in close proximity to the shell to pretreat the lime mud; separating the pretreated lime mud from the flue gas flow; conveying the separated lime mud into the lime kiln, and calcining the separated lime mud in the lime kiln.

Abstract: Applying an acid treatment to eggshells provides a sorbent with unexpectedly high CO2 capture capacity and ability to regenerate.

Abstract: A carbon-dioxide-gas absorber includes a main component of composite oxide, the composite oxide including Ti and X that is at least one of Sr and Ba, and the composite oxide having a molar ratio (X/Ti) of about 1.8 to about 2.2. A substance having a perovskite structure and an (X/Ti) of about 0.9 to about 1.1 or at least one selected from green sheets, green sheet wastes, green-sheet-laminate wastes, and precursors of green sheets including the substance is fired with at least one of strontium carbonate and barium carbonate. An apparatus includes a carbon-dioxide-gas-absorbing mechanical unit that allows a carbon-dioxide-gas absorber to absorb a carbon dioxide gas at about 1.0×104 to about 1.0×106 Pa and at about 500° C. to about 900° C.; and a carbon-dioxide-gas-evolving mechanical unit that evolves the absorbed carbon dioxide gas at about 1000 Pa or less and at at least about 750° C.

Abstract: The present invention provides methods of utilizing biomass materials, in which biomass materials are mixed directly with the reactants and the biomass materials while in combustion can directly heat up the reactants to the temperature required for the chemical reaction to take place. Such chemical reaction takes advantage of the heat energy, carbon element and/or silicon element that are inherently contained within biomass materials. For instance, biomass materials produce powdery or lumpy alkali metal silicates when chemically reacting with alkali metal compounds, synthesize black powder when reacting with nitrates, redox sulfates and decompose carbonates, etc. The present invention is characterized with high heat utilization, no need for external heat source, low power consumption, greatly reduced equipment costs, and the significantly simplified process.

Abstract: The present invention relates to a process for the recovery of elemental sulphur from residues produced in hydrometallurgical processes based on leaching with a solution of sodium sulphide in which the sulphur contained in the residues is selectively leached as sodium polysulphide. The sulphur leaching solution is conveniently regenerated and recycled to the process.

Abstract: The invention features methods and systems for producing commercial quality carbon dioxide (CO2) of 90% to +99% purity using, wet, fine particle limestone produced in a manufacturing operation, for instance, a limestone quarry as a feedstock to a multi-stage limestone calcination process. This process may be fueled with negative cost waste water treatment plant (WWTP) sludge, biomass, coal, or other low cost solid fuels. High reactivity lime product required in the an adjacent paper mill's PCC manufacturing plant is also produced, and steam and heated boiler feed-water is generated and exported to the mill's steam distribution and generation system as well as hot process water for use in the mill's manufacturing operation. The system for calcining fine particle limestone produced in a quarry manufacturing operation and converting it to lime and CO2 comprises a calciner and a combustor linked by a moving media heat transfer (MMHT) system or apparatus.

Abstract: It is an object to provide a method for producing stable alkaline metal oxide sols having a uniform particle size distribution. The method comprises the steps of: heating a metal compound at a temperature of 60° C. to 110° C. in an aqueous medium that contains a carbonate of quaternary ammonium; and carrying out hydrothermal processing at a temperature of 110° C. to 250° C. The carbonate of quaternary ammonium is (NR4)2CO3 or NR4HCO3 in which R represents a hydrocarbon group, or a mixture thereof. The metal compound is one, or two or more metal compounds selected from a group of compounds based on a metal having a valence that is bivalent, trivalent, or tetravalent.

Abstract: Multi-step metal compound oxidation process to produce compounds and enhanced metal oxides from various source materials, e.g. metal sulfides, carbides, nitrides and other metal containing materials with metal oxides from secondary reaction steps being utilized as an oxidation agent in the first reactions.

Abstract: Disclosed is a processes for the production of relatively high purity alkaline earth metal oxides, such as SrO, from relatively low purity forms of carbonated or other oxygenated forms of such metals, such as strontium carbonate. The relatively low purity material is exposed to conditions under which at least a portion of the metal contained therein is converted to a salt that is more readily solvated in a provided solvent than the starting material, while at the same time not substantially increasing the solubility of at least one or more of the impurities in such selected solvent. This step is then preferably followed by removal of solid or otherwise un-dissolved impurities from the solution. After the removal step, the solution is preferably exposed to conditions effective to form a relatively insoluble salt of the alkaline earth metal, such as a strontium salt. The insoluble salt is also preferably one that can be readily and effectively converted to the desired alkaline earth metal oxide, preferably SrO.

Abstract: It is an object to provide a method for producing stable alkaline metal oxide sols having a uniform particle size distribution. The method comprises the steps of: heating a metal compound at a temperature of 60° C. to 110° C. in an aqueous medium that contains a carbonate of quaternary ammonium; and carrying out hydrothermal processing at a temperature of 110° C. to 250° C. The carbonate of quaternary ammonium is (NR4)2CO3 or NR4HCO3 in which R represents a hydrocarbon group, or a mixture thereof. The metal compound is one, or two or more metal compounds selected from a group of compounds based on a metal having a valence that is bivalent, trivalent, or tetravalent.

Abstract: A lime recovery process which mixes dry recycle with spent lime sludge (SLS) forming wet agglomerated calcium carbonate (CaCO3) followed by drying and calcination to produce a reactive lime (CaO) product.

Abstract: A method for manufacturing a cathode active material for a lithium rechargeable battery, including: selecting a first metal compound from a group consisting of a halide, a phosphate, a hydrogen phosphate and a sulfate of Mg or Al; selecting a second metal compound from a group consisting of an oxide, a hydroxide and a carbonate of Mg or Al; combining the first metal compound and the second metal compound to obtain a metal compound, the metal compound containing either Mg or Al atoms; mixing a lithium compound, a transition metal compound and the metal compound to obtain a mixture; and sintering the mixture.

Abstract: Calcium carbonate with high brightness is prepared by treating calcium carbonate and/or the milk of lime used for its preparation by reacting milk of lime with carbon dioxide and/or at least one of the calcium-containing preliminary products used for the preparation of the milk of lime before, during and/or after this reaction with a bleaching agent which comprises at least one compound of the formula (I): A[(CR1R2)SOpM(1/q)]r??(I) where the variables have the following meanings: A is NR3R4, NR3, N or OH; R1, R2, R3, R4 independently of one another, are hydrogen or an organic radical; M is ammonium or metal p is 2 or 3; q is the valency of M; and r is 1 when A = OH or NR3R4, is 2 when A = NR3 and is 3 when A = N; and where variables, if a mixture of compounds is used and/or r=2 or 3, are chosen independently of one another for each individual compound and/or for each [(CR1R2)SOpM(1/q)] group.

Abstract: A method is shown for controlling the presence of soluble sulfate ions in a lime slaking operation in which a source of quicklime is combined with slaking water to form calcium hydroxide product. A complexing agent is added to either the quicklime or the slaking water which is effective to tie up the soluble sulfate ions otherwise available in solution, whereby the agglomeration of calcium hydroxide product is acceptably controlled.

Abstract: A body pigment with a good skin feel for cosmetics is provided which has an appropriate crumbling property and combines slipping property and adhesiveness without compromising oil absorption. The body pigment is comprised of a metal-containing compound and has a structure in which leaf-shaped flakes are combined and/or intersected.

Abstract: A method of producing fine particles of an oxide of a metal, comprising the steps of: preparing an acidic solution which contains ions of the metal; precipitating fine particles of a hydroxide of the metal by adding an alkaline solution to the acidic solution; collecting the fine particles of the hydroxide of the metal precipitated in a mixed solution of the acidic solution and the alkaline solution; mixing fine particles of a carbon with the collected fine particles of the hydroxide of the metal; and heat-treating a mixture of the fine particles of the hydroxide of the metal and the fine particles of the carbon at a predetermined temperature in a non-reducing atmosphere, whereby the fine particles of the oxide of the metal are produced.

Abstract: The present invention relates to a single step process for the synthesis of nanoparticles of phase pure ceramic oxides of a single or a multi-component system comprising one or more metal ions. The process comprises preparing a solution containing all the required metal ions in stoichiometric ratio by dissolving their respective soluble salts in an organic solvent or in water, preparing a precursor, adjusting the nitrate/ammonia content in the system, and heating the system.

Abstract: This invention provides a method for reducing phosphorous in a body of water. This method comprises calcining a plurality of rocks and collecting carbon dioxide formed as a result of the calcining process; crushing the plurality of calcined rocks; pumping source water from the body of water into to a plurality of retaining cells; flocculating the phosphorus in the source water by introducing the plurality of calcined rocks into the source water in the retaining cells; settling out a phosphorous precipitate formed by the flocculating act; adjusting the pH level of the flocculated source water to a predetermined range of values by pumping carbon dioxide created by the calcining of the rocks into the source water to created treated water; and transferring the treated water back to the body of water.

Abstract: The present invention provides methods for the isolation and production of magnesium products from leaching of laterite material with acid. A magnesium compound is formed by downstream treatment of a leach stream after at least one of nickel or cobalt have been brought into solution. Magnesite is then obtained by adding at least one of alkali metal or alkaline earth metal carbonate to the leach stream. The magnesite may be converted into magnesium chloride by adding an acid, such as HCL.

Abstract: A process for the production of ultrafine powders that includes subjecting a mixture of precursor metal compound and a non-reactant diluent phase to mechanical milling whereby the process of mechanical activation reduces the microstructure of the mixture to the form of nano-sized grains of the metal compound uniformly dispersed in the diluent phase. The process also includes heat treating the mixture of nano-sized grains of the metal compound uniformly dispersed in the diluent phase to convert the nano-sized grains of the metal compound into a metal oxide phase. The process further includes removing the diluent phase such that the nano-sized grains of the metal oxide phase are left behind in the form of an ultrafine powder.

Abstract: A process for de-watering lime mud in a Krafft pulping process is described. The process includes an improvement which comprises adding an effective water-removal rate enhancing amount of an alkyleneamine to the lime mud prior to filtration. The preferred alkyleneamine is ethyleneamine, that is, an amine having at least one —(CR2—CR2—NH—)— unit wherein each R is independently is H or an alkyl (straight-chain, branched, or cyclic) group of from about 1 to about 10 carbon atoms. Ethyleneamines include ethylenediamine, diethylenetriamine, triethylenediamine, triethylenetetramine, tetraethylenepentamine, piperazine, aminoethylpiperazine, and ethyleneamine mixtures such as mixtures of ethyleneamine oligomers having an average molecular weight of about 200-500.

Abstract: Magnesium oxychloride and magnesium oxysulfate materials and methods of making the same are disclosed. The materials are cured reaction products of a magnesium oxide, and an aqueous magnesium salt solution. The aqueous salt solution preferably has a specific gravity of about 1.18 to about 1.4. The magnesium oxide has a platelet or flake structure, a bulk density of about 30 lbs/ft3 (about 0.48 g/cm3) to about 70 lbs/ft3 (about 1.12 g/cm3), and a particle density of about 215 lbs/ft3 (about 3.45 g/cm3) or less. The platelet/flake magnesium oxide is prepared, preferably from particles of magnesium oxide ore or brucite ore, using brine-free methods.

Abstract: A process for the preparation of potassium sulfate, sodium bicarbonate and sodium carbonate. The process involves the treatment of potash brines by the reaction of sodium chloride and potassium chloride with calcium sulfate and sodium sulfate. Syngenite precipitate (CaSO4.K2SO4&khgr;H2O) is produced and a first filtrate containing sodium chloride and potassium chloride. The syngenite precipitate is reacted with ammonium bicarbonate at between 70° C. and 100° C., with the result being calcium carbonate precipitate and a second filtrate containing ammonium sulfate and potassium sulfate. The second filtrate is cooled to a temperature of between 20° C. and 50° C. and treated with potassium chloride. A potassium sulfate precipitate results. The sodium bicarbonate is precipitated from the first filtrate by the addition of ammonium bicarbonate to the first precipitate. The sodium bicarbonate may be calcined to form sodium carbonate.

Abstract: A process for the production of high density hydration resistant sintered lime which comprises washing limestone having impurities of less than 2% to remove external impurities, crushing the washed limestone to a size of 25 mm or below, calcining the limestone at a temperature in the range of 1000 to 1150° C. for a period in the range of 2 to 3 hours to form a calcined mass, hydrating the calcined mass, drying the hydrated mass by known methods, deagglomerating the dried hydrated mass with 1 to 4 weight percent of an additive selected from the group consisting of a transition metal oxide capable of forming a low melting compound, a rare earth metal oxide capable of forming a solid solution, and mixtures thereof, pelletizing the resultant mixture at a pressure of at least 1000 Kg/lcm2, sintering the pellets at a temperature In the range of 1500° C. to 1650° C. for a period In the range of 24 hours and allowing the resultant sintered pellets to cool.

Abstract: A limestone furnace calcination process involves injecting finely divided limestone particles into a zone in a furnace at which the temperature of the flue gas stream, as it passes through the zone, is above the minimum calcination temperature and below the minimum effective quicklime utilization/sulfation temperature. In conventional furnaces, the minimum calcination temperature, or the calcium carbonate decomposition temperature, ranges from about 1,365 to 1,430.degree. F. The minimum effective quicklime utilization/sulfation temperature refers to the temperature below which the rate of quicklime sulfation of the lime produced by calcination of the limestone is sufficiently slow to result in negligible calcium sulfate formation on the resultant lime, and in conventional furnace applications ranges from 1,600 to 1,800.degree. F.

Abstract: A method of separating impurities from lime or the calcium carbonate or the lime sludge produced in the chemical recovery system of a pulp mill so that lime sludge or lime is dissolved in a solution containing carbonate or hydrocarbonate in order to dissolve impurities. Subsequently the lime sludge or lime is separated from the solution containing dissolved impurities. A method of causticizing green liquor containing impurities, such as silicon, in two stages. In the first stage green liquor is causticized with such an amount of lime that impurities substantially remain in the liquor. The lime produced in this stage is removed from the liquor and the rest of the lime required in the causticizing is added to this liquor, so that impurities precipitate with the lime sludge produced in the second stage and at least a portion of the lime sludge rich in impurities is discharged from the process.

Abstract: A method of producing an aqueous suspension of calcium hydroxide which comprises passing a gaseous flow incorporating particles of calcium carbonate through a calcining furnace thermally to decompose the calcium carbonate, delivering a flow of the decomposition products formed in the furnace comprising calcium oxide particles suspended in gas comprising carbon dioxide to a vessel wherein the calcium oxide particles are contacted with water to produce an aqueous suspension of calcium hydroxide and separating the aqueous suspension from the said gas.