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.

Abstract: During the manufacture of milk of lime by the suspension of lime hydrate which has a large specific surface and was manufactured with the use of organic solvents and/or organic additives, a stable foam forms which can cause problems in the equipment. This foaming can be prevented during the suspension of the modified lime hydrate in water by the presence of finely-powdered activated cokes.

Abstract: The present invention relates to a flame retardant quality magnesium hydroxide having a BET surface area of less than approximately 10 m.sup.2 per gram (uncoated), an average particle size of approximately 0.5 to 10.0 micron, and less than approximately 0.5% of particles over 10 micron (average particle size measured by laserlight scattering method), and a substantial number of crystals which are generally ovoid in cross section. A process for producing a flame retardant quality magnesium hydroxide is also described.

Abstract: Flue gases exhausted from a lime kiln containing lime kiln dust are treated to produce a high purity calcium carbonate precipitate. This is accomplished by passing the flue gases from the lime kiln through a kiln dust separator so that lime kiln dust containing calcium oxide is removed from the remaining flue gas. The lime kiln dust is mixed with water so that an aqueous suspension of the lime kiln dust is formed. Quicklime or calcium oxide in the lime kiln dust is thus hydrated to form calcium hydroxide. The solids within the suspension are then allowed to settle so that a clear, saturated solution of calcium hydroxide having a pH of about 12.4 is formed. This solution is then contacted with carbon dioxide gas so that the calcium hydroxide reacts to form a high purity calcium carbonate precipitate. This high purity calcium carbonate precipitate is then allowed to settle from supernatant water of the solution.

Abstract: Improved device for slaking of lime, comprising a slaker (10) which is connected to a lime silo (24) and a conveyor (30) for supply of lime, equipped with a motor driven mixer (14) with a specially designed mixing organ. Through pipeline with exit valve the slaker is connected to a distribution tank. An improved process for slaking of lime, using the above-mentioned device and process steps comprising transfer of lime under conveyor (30) from the silo (24) for feeding in weighed quantities into the slaker (10), feeding of weighed water quantities into the slaker for treatment in intervals by means of the mixer (14) and subsequent transfer of the finished lime mixer into the distribution tank. The slaking process is automated and takes place under constant supervision, and the slaking device's regulating valves are controlled by respective, connected limit switches.

Abstract: The invention relates to a method for the preparation of a special calcium and/or magnesium hydroxide in which CaO and/or MgO is reacted with water in the presence of an additive selected among ethylene glycol, diethylene glycol, triethylene glycol, monoethanolamine, diethanolamine, triethanolamine and mixtures thereof, the weight ratio additive to CaO and/or MgO being greater than 0.002:1.

Abstract: The calcium carbonate is prepared by:(a) slaking quicklime in an aqueous medium;(b) carbonating and neutralising the suspension of slaked lime formed in step (a) using a gas comprising carbon dioxide; and(c) separating the precipitated calcium carbonate formed in step (b) from the aqueous medium in which it is suspended. There is added 0.1% to 2% by weight, based on the weight of dry calcium oxide, of a reagent having one or more active hydrogen atoms (or a salt thereof), to the aqueous medium in which the quicklime is slaked in step (a).

Abstract: A method of producing an aqueous solution of slaked lime is disclosed the steps of: introducing water into a slaked lime-dissolving apparatus comprising a dissolving tank, a water supply piping connected to a lower part of the tank, a stirring blade disposed within the tank in its bottom part, an effluent piping connected to an upper part of the tank for discharging aqueous slaked lime solution, and a fluidized slaked lime layer height-control device disposed within the tank above the stirring blade, subsequently introducing a predetermined amount of slaked lime into the tank, feeding water, with low-speed stirring, to the tank from the water supply piping in such a rate that the water in the cylindrical or rectangular upper part of the tank ascends at a rate of from 0.25 to 1.2 mm/sec, and taking out an aqueous solution of slaked lime from the tank through the effluent piping.

Abstract: This invention concerns highly reactive reagents and compositions for purifying exhaust gases and flue gases and for purifying wastewater as well as the processes for producing same and use thereof.The reagents and compositions are mixtures of calcium hydroxide with additives, especially clays, powdered bricks, carbon products such as coal dust and flue ash and optionally water glass which are already porous due to their special production and have a high specific surface area of up to about 200 m.sup.2 /g.Using these sorbents, hydrocarbons and halogenated hydrocarbons, dioxins and furans in addition to heavy metals can be removed from exhaust gases and wastewater. Other advantages include the easy setup of the resulting products and their great safety for dumping.

Abstract: Hydrated lime having high surface area and small particle size is prepared by hydrating lime with an aqueous hydration solution of an organic solvent, and preferably washing the resulting hydrate with an aqueous solution of an organic solvent prior to drying. The high surface area hydrates of the invention are excellent sorbents for SO.sub.2 removal from gas streams.

Abstract: The grit conveyance system of a classifier having a wash region above the liquid layer is provided with a vacuum means in the wash region for positive removal of liquids through a metal screen for disposal.

Abstract: This invention provides a continuous ceramic oxide fiber comprising Al, Y, and O. In another aspect, a method of making the same is taught. The continuous ceramic oxide fiber is useful, for example, as thermal insulation, as a filter component, and as a reinforcement for structural composites.

Abstract: A compact lime slaker has an inner vessel forming an initial slaking chamber disposed in an outer vessel forming a final slaking chamber, with agitators provided in both chambers. Slaked lime-from the final slaking chamber is pumped to a collection trough where slaked lime and grit are removed therefrom, while a major portion of slaked lime, with grit removed is returned to the final slaking chamber. The slaked lime in the final slaking chamber, at an elevated temperature due to the slaking exotherm, insulates the lime being slaked in the initial slaking chamber and provides heat thereto to aid in the initial slaking. Removal of grit from the portion of slaked lime recycled to the final slaking chamber prevents clogging or attrition of components of the slaker.

Abstract: An invention is shown in which a quicklime is hydrated in the presence of a special chemical modifier to produce a controlled temperature hydrate having improved plastic properties and greater surface areas.

Abstract: A wet scrubbing process for removing sulfur dioxide from combustion gases uses an aqueous slurry containing calcium components resulting from the slaking of lime, with the slaked lime formed by mixing lime with water containing a calcium sulfur-oxide salt. The presence of the calcium sulfur oxide salt in the slaking water results in a more easily dewatered sludge that is subsequently removed from the wet scrubbing system.

Abstract: A process is shown for treating flue or exhaust gases in order to remove sulfur oxides and hydrochloric acids in which calcium hydroxide having a surface area of at least 25 m.sup.

Abstract: This is a process and a device making use of a process for forming calcium oxide from pulverulent calcium carbonate, according to which an initial bath of pulverulent calcium oxide is produced in a reactor (1, 31) in the form of a fluidized bed which is heated electrically to a temperature higher than of the order of 900.degree. C., and the said pulverulent calcium carbonate is then introduced continuously into the bath while the temperature of the bath is always kept higher than of the order of 860.degree. C. by electrical heating, to dissociate the said calcium carbonate into calcium oxide and carbon dioxide.

Abstract: Hydrated lime having high surface area and small particle size is prepared by hydrating lime with an aqueous hydration solution of an organic solvent, and preferably washing the resulting hydrate with an aqueous solution of an organic solvent prior to drying. The high surface area hydrates of the invention are excellent sorbents for SO.sub.2 removal from gas streams.

Abstract: A process is shown for treating flue or exhaust gases in order to remove sulfur oxides and hydrochloric acids in which calcium hydroxide having a surface area of at least 25 m.sup.2 /g and a moisture content lower than 50% is injected in the gases to be treated either alone, or in a mixture with magnesium hydroxide. The calcium hydroxide used in the process is prepared by reacting quicklime or dolomitic quicklime with water in the presence of a glycol or an amine companion additive.

Abstract: The prior-art CO.sub.2 adsorbent masses used in oxygen-supplying respirators have the disadvantage that they can be granulated only very poorly. The granules have low strength and a tendency to dusting. The goal of the present invention is to produce harder granules which do not give rise to dusting any longer. This is achieved according to the present invention by adding an alkali salt of an oxo acid, preferably sodium hexametaphosphate, to the calcium hydroxide paste prior to the granulation. The present invention is not limited to this salt, but it is also possible to use alkali salts or other oxo acids, such as orthophosphoric acid, sulfuric acid, hypermanganic acid, chromic acid, and vanadic acid. This leads to a substantial increase in the strength to the calcium hydroxide granules without any reduction of their CO.sub.2 binding capacity.

Abstract: Magnesia pellets are formed from finely-divided, highly reactive, lightburned magnesia (MgO) particles by granulating such powders in conventional equipment using either an organic liquid or an organic liquid-binder mixture. The organic liquid may be an alcohol or a ketone the alkyl groups of which, independently, can have from 1 to 4 carbon atoms. Magnesium chloride and water are among disclosed binders which may be used in combination with said organic liquid. The organic liquid should be more than about 80% of any admixtures with water.

Abstract: A lime hydrating plant is provided with an external cooler 16 in which the rawer solids portion which is recirculated into a return flow fluidizer 2 (hydrater) is cooled outside the hydrater. This means that less water has to be atomized into the return flow fluidizer 2 than by known plants in order to keep the adequate temperature essential for the hydrating process. Thus dew point decrease may be avoided and a highly reactive hydrated lime may be produced.

Abstract: The dry slaking of lime is carried out continuously in a vessel from which an exhaust gas is removed. Hot gas, preferably a flue gas to be desulfurized, is added to the exhaust gas to prevent it from contacting the inner surface of the exhaust gas duct and thereby reduce the tendency for deposits in lines traversed by the exhaust gas.

Abstract: A lime processing apparatus has a transportable base and a reaction vessel mounted on the base. The reaction vessel has an inlet end for receiving a pressurized flow of water and lime and has a discharge end. A mechanical agitator is rotatably mounted within the vessel interior for mixing the water and the lime within the vessel to form a slurry product and to move the slurry product through the vessel to continuously discharge product from the discharge end. An elevator mechanism on the transportable base elevates the discharge end of the reaction vessel whereby any unreacted solids in the slurry product are collected at the inlet end for removal through a solids discharge conduit.

Abstract: A method for removing sulfur compounds from flue gases in which a slurry of calcium oxide and water is formed and exothermically reacted to form a hydrate containing calcium hydroxide in substantially saturated solution. The calcium hydroxide is converted to relatively fine particles as the saturated liquid is flashed to steam. The fine particles are passed in a counter-flow relationship with the flue gases so that the sulfur compounds from the flue gases react with the calcium hydroxide in the particles to form calcium sulfate.

Abstract: A process is provided for producing dry calcium hydroxide by slaking finely divided or ground, softly burnt lime by carrying out the blending of slaking liquid consisting of 30 to 50 parts by volume water and 70 to 50 parts by volume organic solvent with the lime at a temperature below 45.degree. C. in a mixing vessel, subsequently transferring the reaction mixture into a main reaction vessel where the mixture is heated by means of a heating device to a temperature of from 50.degree. to 70.degree. C., and carrying out the final reaction in another reaction vessel. In the mixing vessel, the ratio of lime to slaking liquid is selected in a way such that a final reaction temperature of 85.degree. to 110.degree. C. is reached in the final reaction vessel.

Abstract: The present invention seeks to provide a method in which the soda lye obtained as a result of cellulose cooking process and unslaked lime are used for producing white liquor which can be re-used in the cooking process. In this method, the heat released by the slaking of lime with soda lye is recovered by a high pressure slaking process wherein the heat is transferred, either to the steam separating from the lye, which steam is then led to the desired application, or to some other medium to be heated. The present invention is characterized in that the soda lye to be causticized is divided into two parts, one of which is used for the slaking of lime by adding to it all the unslaked lime needed for the causticizing process, and that, following slaking, the two volumes are brought together for the actual causticizing reaction involving the total amount of lye needed. The present invention provides the advantage that the amount of lye needed is smaller, and so the temperature can be increased.

Abstract: The invention is an improved lime slaker in which the lime is combined with the slaking liquor in a vertical conduit which extends below the level of the liquor in the slaker vessel. The slaking liquor is introduced into the conduit at a high velocity tangential to the interior surface of the conduit to flush the lime into the vessel. The slaker includes a vertical vent pipe that extends through the bottom of the vessel. In a preferred embodiment, the inlet of the vent pipe is surrounded by an entrainment separator. Removable covers permit convenient access for inspection and cleaning of the conduit and the vent pipe.

Abstract: A lime slaking system for hydration of lime and removal of unwanted grit, particularly for formation of reactive slaked lime to be used in SO.sub.2 scrubbing of effluent gases, comprising a series of slaking vessels (10,12) for reacting CaO and water while agitating the reactants, a dilution mix tank (14) receiving a viscous slaked lime slurry from the vessels, diluent for the dilution tank comprising an upstream classifier overflow stream (16), a cyclone (19) receiving pumped diluted slurry from tank (14), the overflow (21) of the cyclone providing usable slaked lime product and the underflow (22) exiting to the upstream classifier 24 where grit materials are separated and removed. Dilution for effective classification is provided by spent scrubbing process water containing appreciable sulfate ions.

Abstract: A method for forming a lime slurry in which a sulfate compound is mixed with an aqueous slaking medium and in which the resulting sulfate/water mixture is admixed with calcium oxide.

Abstract: The invention is an improved lime slaker in which the lime is combined with the slaking liquor in a vertical conduit which extends below the level of the liquor in the slaker vessel. The slaking liquor is introduced into the conduit at a high velocity tangential to the interior surface of the conduit to flush the lime into the vessel. The slaker includes a vertical vent pipe that extends through the bottom of the vessel. In a preferred embodiment, the inlet of the vent pipe is surrounded by an entrainment separator. Removable covers permit convenient access for inspection and cleaning of the conduit and the vent pipe.

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 is provided for improving the sulfur capture potential of lime in the fluidized bed combustion of coal and for improving the flow characteristics of the feed coal therefor comprising collecting partially sulfated limestone particles from the fly ash of the flue gas from the fluidized bed combustor, and (a) retaining said particles in the flue gas stream, thereby hydrating said particles, and returning said particles to the combustor; or (b) mixing said partially sulfated limestone particles with wet coal thereby drying said coal and simultaneously hydrating unreacted calcium oxide to form calcium hydroxide, and recycling said mixture of dry crushed coal and calcium hydroxide into said fluidized bed combustor; or (c) introducing wet coal in the flue gas upstream from said collected particles, thereby providing moisture to hydrate said particles, and returning said hydrated particles to the combustor.

Abstract: An improved lime slaking system including agitator means effective for mechanical comminution of particulate lime during the hydration thereof.

Abstract: An already existing conventional lime production plant using a rotary kiln discharging directly into a rotary cooler, is converted reversibly to the production of dry hydrated lime by introducing water into contact with the lime in the cooler sufficient to hydrate the lime without requiring any significant change in the operating parameters of the lime production such as material throughput, cooling and combustion air supply rates and firing conditions.

Abstract: This invention relates to an apparatus for the continuous preparation of aqueous solution of slaked lime solids with fresh water. The apparatus comprises a main vessel having an inverted truncated cone including a smallest and closed bottom. There is provided a dispenser for supplying material slaked lime solids to said main vessel at or nearly at the top end thereof from above, and a constant headed fresh water reservoir for supplying fresh water to the main vessel at a place selected therein in close proximity to the smallest bottom through a piping. A flow rate adjusting means is arranged in this piping. At least a mechanical or fluid agitator is provided at a close proximity to the vessel bottom. Means for the take-up of the formed product solution in an overflowing manner from the main vessel is provided at the top thereof.

Abstract: This invention relates to hydroxyapatite, ceramic material, implant material and a process for preparing thereof. The ceramic material is hydroxyapatite ceramic having an excellent thermal stability.

Abstract: An improved lime slaking system including agitator means effective for mechanical comminution of particulate lime during the hydration thereof.

Abstract: In the preparation of homogeneous lime water solution for use in the purification of waste water, a lime water suspension is used as starting material. The lime water suspension is supplied at the bottom of a compartment in which it is caused to rise in order to leave at the upper part, while passing lamellas during its upward movement. The lamellas are arranged in such a way that they will create a sludge zone at their lower part in the compartment, in which zone the rising lime suspension is filtered, whereas they create at their upper part in the compartment a clarification zone in which fine particles are separated.

Abstract: A stable, homogeneous, and flowable soil neutralizing slurry of particulate material such as calcium carbonate or dolomitic lime as provided using a suspending agent and a dispersant. A polyanionic dispersant is used in limited quantities to increase the concentration of particulate material and a gelling grade clay mineral is used as a suspending agent to prevent settling of the dispersed particulate material. A partial dispersion technique is used whereby the amount of dispersant used is limited so that the particulate material is dispersed but not the clay mineral.