Abstract: Magnesium hydroxide slurries having the following characteristics: (i) having a solids content of between 40-80 wt. % based on the weight of the slurry with the balance being water; (ii) containing between 0.01-5.0 wt.% of at least one viscosity modifying agent or dispersant based on the weight of the slurry selected from the following groups: (1) inorganic acids having a molecular weight less than 130 amu and their inorganic salts excluding H.sub.2 SO.sub.4, H.sub.3 PO.sub.4, silicic acid and salts having an alkali metal as sole cation; (2) low molecular weight (i.e.

Abstract: A convenient process for making builder material which has substantially improved performance and is significantly less expensive than previous builders is provided. The builder material has improved performance in that it unexpectedly has a high calcium ion exchange capacity and rate, and is easy to handle, process and disperse in washing solutions. In its broadest aspect, the invention is directed to a process involving converting starting materials (via any means including but not limited to heating and precipitating) to a builder material having at least one crystalline microstructure including a carbonate anion, calcium cation and at least one water-soluble cation. The microstructure should have a sufficient number of anions and cations so as to be "balanced" or "neutral" in charge.

Abstract: Method and apparatus for obtaining finely pulverized quicklime powder having high reactivity by calcining fine limestone powder, particularly, of particle sizes 1-100 micrometers. Coarse particles of inert substance, particularly, those having diameters of 100-1500 micrometers, are fluidized with high temperature gas to form a fluidized bed, and fine limestone powder is supplied into the fluidized bed. The fine limestone powder captured by the fluidized bed is calcined therein and the resulting quicklime powder is carried away by the stream of fluidizing gas and recovered with cyclone and bag filter. Coarse limestone may be used instead of or together with the coarse inert substance particles.

Abstract: An improved process for the production of road deicer products preferably containing calcium magnesium acetate or calcium magnesium acetate/calcium magnesium propionate is provided. The process involves first providing a residual water plant sludge starting material containing calcium and magnesium compounds, and reacting this sludge with stoichiometric quantities of at least acetic acid and more preferably both acetic and propionic acids. The resultant reaction product can then be dried, ground and granulated to provide a dry, free flowing road deicer product.

Abstract: A process for calcining limestone to lime to produce a low sulfur content lime product, while combusting a sulfur-containing carbonaceous fuel in a rotary kiln to provide heat for the calcination. A finely divided lime hydrate is added to the rotary kiln adjacent the combustion flame, such that the lime hydrate particles react with sulfur-containing contaminants in the hot combustion gases to form lime hydrate-sulfur reaction products, such as calcium sulfate, which are retained in the gaseous flow and removed from the rotary kiln.

Abstract: Lime mud from kraft pulp recovery operations is processed using dielectric hysteresis heating, in a two-stage operation, in which wet lime mud first is dried then the dried lime mud is decomposed to lime and carbon dioxide. A two-zone lime mud calciner is employed in which the lime mud is conveyed horizontally, with drying being effected in the first zone and then decomposition being effected in the second zone. A co-current flow of purge air removes steam generated in the first zone and a counter-current flow of purge air removes carbon dioxide generated in the second zone.

Abstract: A process for the continuous production of a calcined product containing a high level of reactive oxide valves, from a preheated raw material containing calcium carbonate values, said process comprising,(a) introducing the preheated raw material to the bottom of a generally vertically oriented gas suspension calcining furnace, whereby said preheated raw material is thereafter suspended in an ascending stream of heated gas to thereby pass vertically upwardly through the gas suspension calcining furnace;(b) passing the ascending gas stream through a plurality of burners, into which fuel and air are injected, that are vertically spaced from each other, in the gas suspension furnace, at a number of levels in the flow direction of the heated gas, and(c) collecting the calcined product.

Abstract: Disclosed is a novel basic magnesium carbonate represented by the following general formula:nMgCO.sub.3.Mg(OH).sub.2.mH.sub.2 Owherein n is a number of from 3 to 5 and m is a number of from 3 to 5,which consists of porous particles composed of an aggregate of plate crystals having an average particle size of 1 to 50 .mu.m and a specific surface area of 10 to 70 m.sup.2 /g, wherein in the fine pore size distribution of the particles, the volume of fine pores having a radius smaller than 100 .ANG. is at least 0.02 cc/g and the volume of fine pores having a radius smaller than 75,000 .ANG. is at least 0.8 cc/g.This novel basic magnesium carbonate is highly improved over conventional basic magnesium carbonate in such properties as filling property, dispersibility and flowability.

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: A composite oxide synthesized by a citrating process and utilized in functional ceramics materials is prepared by the following process. Co-precipitants or mixtures of at least one component selected from the group consisting of carbonates, basic copper and/or hydroxides of elements which compose a composite oxide are reacted with citric acid in an aqueous solution or in an organic solvent. The elements are selected from at least one element of the group consisting of Y, rare earth elements, transition elements, and alkali metal or alkaline earth metal elements. The citrate compound formed is baked to complete the composite oxide.The composite oxide synthesized by this invention has superconduction at the most temperature of 93.degree. K. with excellent Meissner effect.

Abstract: Fermentors, reactors and processes for preparing magnesium enriched calcium magnesium acetate (CMA) (Mg:Ca mole ratios of 1:1 to 20:1) by reacting a dolomitic lime product with a Mg:Ca mole ratio less than one with dilute acetic acid, such as in fermentation broths. A process to prepare a mildly aklaline mineral product by calcining the dolomite under conditions to convert only the MgCO.sub.3 to MgO and treating the selectively calcined dolomite with acidic solutions to dissolve largely the MgO, leaving the original CaCO.sub.3 matrix intact. The mildly alkaline mineral product includes a highly porous structure derived from dolomite, consisting of a matrix of CaCO.sub.3 with smaller amounts of MgO and interspersed with a regular array of voids on a molecular scale.

Abstract: In the heat treatment of lime mud, the lime mud to be introduced to a lime reburning kiln is dried in a pneumatic drier by flue gases from the lime reburning kiln in order to regenerate the lime contained in the mud. Prior to drying, the lime mud is thickened in a drying filter to a dry solids content of over 75%, preferably to approximately 80%. In this way, the lime reburning kiln can be made approximately 30% shorter than conventional kilns, and the apparatus is simpler than the conventional apparatus provided with a pneumatic drier.

Abstract: A process for the preparation of high purity calcium titanate hydrates, particularly various forms of kassite, is disclosed. Calcium carbonate and titanium tetraisopropoxide are used as starting materials. The process utilizes a hydrothermal reaction step. Hydrates having both hexagonal plate form, wherein the particles have a hexagonally shaped flat plate-like morphology, and lath form, wherein the particles have a rod-like morphology are produceable according to the process. Particle morphology is determined by the choice of process parameters, especially the rate of heating during the hydrothermal reaction step. Kassite particles of the hexagonal plate form, which are useful as a high opacity paper coating pigment, are produced when the rate of heating is less than or equal to 1.5.degree. C./min. Faster rates of heating result in kassite particles of a lath form. These particles are useful as a reinforcing material in polymers and ceramics.

Abstract: A process for preparing monoclinic celsian from AlF.sub.3, Al.sub.2 O.sub.3, BaCO.sub.3, and fused SiO.sub.2 powders by heating an intimate mixture of the powders (1) at from about 700.degree. to 900.degree. C. to form topaz and then (2) at a temperature as low as 900.degree. C. to produce monoclinic celsian. The reactions take place in an atmosphere of the gases generated by the reactions.

Abstract: A process for preparing monoclinic celsian from topaz and BaCO.sub.3, pows by heating an intimate mixture of the powders at a temperature of from 900.degree. C. to less than 1590.degree. C. in an atmosphere of the gases generated by the monoclinic celsian formation reaction itself.

Abstract: A lightweight magnesia clinker containing magnesium oxide in an amount of more than 85 wt. % and having an apparent porosity of more than 40 vol. % and a bulk specific gravity of less than 2.0 g/cm.sup.3 is disclosed. In the lightweight magnesia clinker, the amount of magnesia clinker particles having a particle diameter of smaller than 3 mm is more than 90 wt. % of the amount of all magnesia clinker particles, and the amount of pores formed in the magnesia clicker particles having a pore size of smaller than 50 .mu.m is more than 90 vol. % of the amount of all pores. A process for the preparation of said lightweight magnesia clinker is also disclosed.

Abstract: A process is disclosed for producing a homogeneous mixture of co-precipitated carbonate salts capable of reacting together in an oxygen atmosphere at an elevated temperature to form a superconducting ceramic which comprises forming a first solution by dissolving in a first solvent maintained at a temperature of from about 15.degree. to 35.degree. C. a rare earth compound, an alkaline earth metal compound, and a copper compound capable of reacting with a carbonate ion to form an insoluble precipitate of carbonate salts in the solvent used to form the solution; forming a second solution containing a carbonate-forming compound dissolved in a second solvent miscible with the first solvent; blending the first and second solutions together at a temperature of from about 0.degree. to 15.degree. C.

Abstract: A glass manufacturing process using a granular, free-flowing form of alkaline earth metal carbonate, e.g., barium or strontium carbonate, is disclosed. The alkaline earth metal carbonate has a relatively high bulk density and is made without sintering, grinding, or briquetting. The carbonate is prepared from a fine particle size material by the following steps:(a) forming a suspension of the carbonate in water with enough deflocculating agent, e.g., sodium polyacrylate or sodium hexametaphosphate, to substantially completely deflocculate the carbonate;(b) drying the resulting suspension, at a temperature that is elevated, but without heating the carbonate to its sintering point, for example, by spray drying in a spray drier operating at an inlet temperature in the range of about 400.degree. to 600.degree. C., to obtain a granular material primarily passing 10 mesh and held on a 150 mesh screen (Tyler); and(c) heating the granular material to about 600.degree. to 700.degree. C.

Abstract: A method of converting fine particle size alkaline earth metal carbonate, e.g., barium or strontium carbonate, into a free-flowing granular form with relatively high bulk density, without sintering, grinding, or briquetting, is disclosed. It involves the following steps:(a) forming a suspension of the carbonate in water with enough deflocculating agent, e.g., sodium polyacrylate or sodium hexametaphosphate, to substantially completely deflocculate the carbonate;(b) drying the resultant suspension at a temperature that is elevated, but without heating the carbonate to its sintering point, for example by spray drying in a spray drier operating at an inlet temperature in the range of about 400.degree. to 600.degree. C., to obtain a granular material primarily passing 10 mesh and held on a 150 mesh screen (Tyler); and(c) heating the granular material to about 600.degree. to 700.degree. C., which causes it to shrink, thereby increasing its bulk density by at least about 5%, preferably at least 10 or 20 percent.

Abstract: A process for producing magnesium oxide and/or hydrates thereof from predominantly magnesium or magnesium-calcium raw materials, and optionally producing calcium carbonate, whereby the raw material is roasted if necessary to form a mixture of magnesium oxide and calcium oxide. The calcium oxide is then dissolved from the mixture using an aqueous solution containing an organic amine and a salt of an organic amine with an acid capable of forming a soluble calcium salt with said organic amine. Separating the solution from the undissolved magnesium oxide and treating the solution with carbon dioxide will cause the dissolved calcium to be precipitated and calcium carbide.

Abstract: Superior homogeneity in ceramic materials is achieved by forming an aqueous solution of trichloroacetates of certain metals, heating the solution to decompose the trichloroacetates to form carbonate precipitates, and recovering the carbonate precipitates. The latter can be calcined to form superconductors. For example, oxides, or carbonates of Y, Ba, and Cu are dissolved in aqueous trichloroacetic acid and the solution is heated to decompose trichloroacetate ions and to form mixed carbonates, which precipitate. The precipitate is recovered and calcined to form a superconducting material.

Abstract: A method for calcination of a calcium carbonate material comprising heating the calcium carbonate material to a temperature and for a time sufficient to calcine the material to the degree desired while in the presence of a catalyst; said catalyst comprising at least one fused salt having the formulaMCO.sub.3.CaCO.sub.3.CaO.H.sub.2 O.sub.x,wherein M is an alkali metal and x is 0 to 1 and formed by fusing MCO.sub.3 and CaCO.sub.3 in a molar ratio of about 1:2 to 2:1, and a blend adapted to be heated to CaO comprising a calcium carbonate material and at least one such fused salt.

Abstract: The invention describes a process for overbasing a substrate comprising mixing the substrate, water, a phenol, a source of magnesium and a carbonating agent, wherein the water is retained throughout the overbasing reaction and provided further that the weight ratio of the water to the magnesium is in a 10:1 to 1:5 weight ratio, thereby obtaining a magnesium overbased substrate.

Abstract: Carbonate-containing mineral fillers, pigments and similar materials are disclosed which are characterized by a combination of four features. These carbonate-containing materials can be used in particular in dyes, paints, paper pulps, paper coatings and plastics to great advantage. In addition, a method of preparing these carbonate-containing materials is disclosed.

Abstract: Energy conserving limestone calcining system, including a process and apparatus in which in a first step or kiln zone limestone is heated, e.g., at 1700.degree.-2100.degree. F., sufficiently to achieve more than only about 50 or 60%, e.g.

Abstract: The present invention disclosed a magnesia clinker excellent in corrosion resistance, which is useful for a magnesia carbon refractory and also for a refractory for steel manufacturing furnace, and the magnesia clinker is characterized by:(a) having a purity of MgO of 97 wt. % or higher;(b) containing 2.0 wt. % or less of CaO;(c) containing 0.01 wt. % or more of B.sub.2 O.sub.3 ;(d) containing 0.3 wt. % or less of SiO.sub.2 ;(e) containing impurities other than MgO, CaO, B.sub.2 O.sub.3 and SiO.sub.2 of 2 wt. % or less;(f) having a bulk density of 3.35 (g/cc) or higher and an apparent porosity of 3.0 (vol. %) or less; and(g) having a mean crystal size of magnesia of 100 .mu.m or larger.

Abstract: High purity magnesium oxide is obtained from a magnesite-containing ore, the impurities of which include calcium compounds. The ore is first calcined and the resulting magnesium oxide is converted to magnesium chloride by leaching with an ammonium chloride solution. Calcium chloride is also produced at the same time. The resulting magnesium chloride and calcium chloride are treated with carbon dioxide to form calcium carbonate and magnesium carbonate which can be precipitated and filtered out of the resulting magnesium chloride solution. The magnesium chloride solution is then reacted with ammonium carbonate to produce a magnesium carbonate trihydrate crystal slurry containing ammonium chloride. The ammonium chloride is subsequently removed and returned to the ammonia recovery stage for leaching of the calcined magnesium oxide while the crystals are dried and decomposed into carbon dioxide and magnesium oxide.

Abstract: The method of treating a limestone slurry to remove water therefrom comprising admixing therewith at least about 0.25 part by weight of a fluidizing agent for each 100 parts by weight of solids in said slurry, said fluidizing agent consisting essentially of a micelle-forming surfactant and a protective colloid in a ratio of from about 2:1 to 1:2; the resultant limestone mud containing at least about 70% solids; and a fluidizing agent for dewatering a limestone slurry consisting essentially of a micelle-forming surfactant and a protective colloid in a ratio of from about 2:1 to 1:2.

Abstract: The invention relates to a process for the decarbonation of minerals, in powdered form, in a fluidized bed. For example, the process applies to the production of quick lime and/or magnesia from lime stone and/or dolomite fines which are not rendered sufficiently valuable at present.The process comprises recycling a portion at least of the carbon dioxide produced to be used as sole fluidizing gas, the fluidized bed being heated to the desired decarbonation temperature by direct heat supply within the fluidized bed by means of electric devices.Production of decarbonated minerals and of CO.sub.2.

Abstract: A demolition agent for brittle materials which is prepared by pulverizing a quick lime clinker including 0.5 to 10.0% by weight of phosphorus components in terms of P.sub.2 O.sub.5.

Abstract: Limestone is calcined by being suspended in hot gas produced by combustion of a low-carbon fuel to produce a quicklime of high surface area, which in one embodiment is used for flue gas desulfurization.

Abstract: Finely divided lime, at any degree of slaking, is introduced in a steady stream into an agitated reactor designed to produce pellets or aggregates. Concentrated acetic acid is simultaneously introduced in a steady stream at a rate equal to the chemical combining rate required to produce calcium magnesium acetate. Water content of the reaction stream is critical; the mol ratio of water, including water of neutralization, to the calcium magnesium acetate product must fall in the range 3.3-7.0 in order to form the desired pellets and to avoid sticking, caking, and dust emanation from the reactor. Product pellets are drawn off in a stream from the reactor and dried for use as a non-polluting roadway and walkway deicer. Traction agent is optionally incorporated into the deicer pellets by introducing a steady stream of traction agent to the reactor simultaneous with raw materials introduction. Magnesium-to-calcium ratios greater than one are achieved by blending dolime with magnesium-rich ore.

Abstract: High density magnesia clinker characterized by having a chemical composition, as oxides in weight %, ofMgO: 97.5% or moreCaO: 0.8-2.0%SiO.sub.2 : 0.12-1.0%Fe.sub.2 O.sub.3 : 0.3% or lessAl.sub.2 O.sub.3 : 0.15% or lessB.sub.2 O.sub.3 : 0.03% or lesswith a bulk density of at least 3.48 g/cm.sup.3. The said high density magnesia clinker can be produced by forming magnesium oxide by calcination of naturally occurring magnesite having a composition, based on ignition in weight %,MgO: 97.5% or moreCaO: 0.8-2.0%SiO.sub.2 : traces to 0.15%Fe.sub.2 O.sub.3 : 0.3% or lessAl.sub.2 O.sub.3 : 0.15% or lessB.sub.2 O.sub.3 : 0.1% or less,grinding the same after, or with, addition of amorphous silica, silica gel or a silicon compound capable of forming SiO.sub.2 by dead-burning in such a manner as to have the SiO.sub.2 content of 0.12-1.0% after dead-burning and dead-burning.

Abstract: A nonexplosive chemical composition for gently and noiselessly breaking a rock or concrete mass. The composition comprises a principal component which is prepared by calcining a starting mixture comprising 100 parts by weight of quick lime and 1-20 parts by weight of calcium fluoride. In rock or concrete breaking operations, this composition in the form of aqueous slurry is poured into drill-holes and left to spontaneously hydrate and set with development of expansion pressure. For adequate retardation of the hydration, preferably a second fluoride such as Na.sub.2 SiF.sub.6 which gives CaF.sub.2 by reaction with CaO at the calcination temperature is added to the starting mixture. As an alternatively preferable method for the same purpose, an amino acid compound and/or a lignosulfonate is used as a hydration retarding agent which is mixed with the calcined principal component. Various auxiliary agents may optionally be added to this composition.

Abstract: The subject of the invention is a process for the production of pure burnt lime using gaseous fuels produced from energy carriers, in particular industrial wastes, wherein the energy carriers are gasified in an installation consisting of a fluidized bed and a cyclone, and the noxious substances released during the thermal decomposition are separated off by means of adsorbents, before they come into contact with the lime being burned.

Abstract: Very pure magnesium oxide is obtained from ore containing magnesium, more particularly ore containing magnesium carbonate, by calcining the ore and leaching the resulting magnesium oxide with carbon dioxide and calcium chloride solution to produce magnesium chloride solution. Carbon dioxide and ammonia are added, so as to precipitate magnesium carbonate trihydrate, which is decomposed to magnesium oxide.

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 instant invention is directed to a method of inhibiting and dispersing calcium oxide deposit formation in coal-fired lime kilns, comprising burning the coal in the presence of from 1 to 2 pounds/ton of coal of a blend of 80 to 95%, by weight, magnesium oxide and 5 to 20%, by weight, copperoxychloride.

Abstract: Magnesium is removed from brine by contacting the brine with calcium hydroxide at temperatures above about 80.degree. C. but below the boiling point of the brine. The contacting results in the formation of magnesium hydroxide precipitate which is substantially insoluble in the mother liquor at those temperatures and strontium hydroxide which is dissolved in the mother liquor. When the contacting is carried out at a temperature above about 90.degree. C., magnesium hydroxide precipitate is fast settling and filterable; accordingly, it is removed from the mother liquor by a conventional process, such as filtering. The mother liquor is then cooled to cause the precipitation of at least a substantial part of strontium hydroxide present in the mother liquor. The precipitate of strontium hydroxide is recovered by a conventional process such as filtering. If precipitation upon cooling is insufficient, carbon dioxide gas is introduced into the mother liquor to effect the precipitation of strontium hydroxide.

Abstract: The invention relates to an improvement in a method of regenerating alkaline or alkaline earth metal oxides or hydroxides from solution particularly in delignification processes wherein a suitable transition metal such as ferric oxide is burnt with the solution to produce a mixed oxide that is subsequently treated in hot water to regenerate the alkaline or alkaline earth metal oxide or hydroxide and precipitate the transition metal oxide. The improvement controls the presence of fines in the transition metal oxide to maintain these at an acceptable level in the fluidized bed combustion zone. This is achieved by contacting the fines with spent liquor from a delignification process. The invention also provides for the pelletization of the fine material of the transition metal oxide and spent delignification liquor can be used as a binder in the formation of such pellets.

Abstract: A method and apparatus for calcining lime, dolomite or similar materials in which the raw material to be calcined is preheated in a preheating zone by exhaust gases from a calcining zone, cooled by means of combustion air in a cooling zone, the combustion air passing from said cooling zone into said calcining zone and then into the preheating zone. A specific improvement of the invention resides in adding fuel in the calcining zone at a plurality of spaced locations along the calcining zone in the direction of flow of the combustion air therethrough.

Abstract: Heat treated anionic clay mineral is an improved catalyst for the conversion of acetone to mesityl oxide and isophorone as well as for the aldo condensation of other carbonyl-containing compounds.

Abstract: A causticization method including the steps of calcining limestone in the presence of additive means for producing lime of increased lime efficiency relative to the lime that would result from calcining such limestone without the presence of the additive means, lime efficiency being determined on a sodium carbonate solution for which conditions, other than the character of the lime, are fixed, and subsequently feeding the lime of increased lime efficiency into the sodium carbonate solution for producing sodium hydroxide and calcium carbonate from the sodium carbonate.

Abstract: A process of making a calcium acetate-containing solution having a pH value at room temperature between about 7 and about 8 is provided comprising reacting acetic acid with a carbonate compound, adding calcined limestone, and optionally finishing off the acid-base reaction with an amount of an alkali metal hydroxide comprising from about 2% to about 5% of the total stoichiometric complement to the amount of acetic acid. Further process options which may be used in the preparation of deicing agents include adding coarse limestone to the above-prepared calcium acetate-containing solution in amounts up to 10% by weight and converting the solution into solid flakes. The calcium acetate salt product can be mixed with an inert solid material having good anti-slip properties.

Abstract: A process of reacting aqueous acetic acid and crushed raw limestone in such a way as to produce a mixture of calcium acetate, calcium acid-acetate, and unreacted raw limestone devoid of undesirable fine limestone. Such a product is useful in winter highway treatment, where the environmentally safe soluble acetates function to depress the freezing point of water, and the limestone acts as a roadway traction agent. When as much as 3 mols of acetic acid per mol of active calcium carbonate in limestone are used, all the limestone is consumed, with virtually 100% yield of calcium acid-acetate.

Abstract: A process of making a calcium acetate-containing solution having a pH value at room temperature between about 7 and about 8 is provided comprising reacting acetic acid with a carbonate compound, adding calcined limestone, and optionally finishing off the acid-base reaction with an amount of an alkali metal hydroxide comprising from about 2% to about 5% of the total stoichiometric complement to the amount of acetic acid. Further process options which may be used in the preparation of deicing agents include adding coarse limestone to the above-prepared calcium acetate-containing solution in amounts up to 10% by weight and converting the solution into solid flakes.

Abstract: A method and apparatus for calcining minerals, particularly limestone, in a shaft kiln having at least two vertically spaced levels including cooled hollow supports through which a solid fuel is introduced into the kiln. One feature of the present invention resides in employing a granular coal as the fuel while other features are involved with the distribution of fuel between various inlet points, suspension of the fuel in an airstream, and the mechanical construction of the fuel conduits and their support located within the shaft kiln.

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: Calcination of limestone to form a finely divided lime product without substantial contamination by impurities (especially carbon and ash) is accomplished in a secondary fluidized bed with reaction heat provided by recirculating entrained particles from a primary multisolid fluidized bed combustor.

Abstract: Finely divided lime, at any degree of slaking, is introduced in a steady stream into an agitated reactor designed to produce pellets or aggregates. Concentrated acetic acid is simultaneously introduced in a steady stream at a rate equal to the chemical combining rate required to produce calcium magesium acetate. Water content of the reaction stream is critical; the mol ratio of water, including water of neutralization, to the calcium magnesium acetate product must fall in the range 3.3-7.0 in order to form the desired pellets and to avoid sticking, caking, and dust emanation from the reactor. Product pellets are drawn off in a stream from the reactor and dried for use as a non-polluting roadway and walkway deicer. Traction agent is optionally incorporated into the deicer pellets by introducing a steady stream of traction agent to the reactor simultaneous with raw materials introduction. Magnesium-to-calcium ratios greater than one are achieved by blending dolime with magnesium-rich ore.