Abstract: The present disclosure relates to a phase change material (PCM) composition and a process for preparation thereof, wherein said composition comprising a phase change material, glass fibers and xanthan gum. In a preferred embodiment, the phase change material is water (or ice) and the g lass fibers are glass wool. The disclosure also relates to a stackable and sealable package enclosing the PCM composition. In a particular embodiment, the PCM composition is used to prepare a cold box that may be used in cold chain transportation.

Abstract: The present invention discloses a method for producing the alpha-calcium sulfate hemihydrate bone graft, which comprises the following steps: mixing calcium sulfate dihydrate and deionized water to produce calcium sulfate dihydrate paste; stirring and heating the calcium sulfate dihydrate paste at least 160° C. within 100-350 psi to produce the conversion calcium sulfate hemihydrate, filtering the conversion calcium sulfate hemihydrate with high temperature to produce the filtered calcium sulfate hemihydrate, and washing the filtered calcium sulfate hemihydrate by absolute alcohol to get the alpha-calcium sulfate hemihydrate bone graft. The present invention does not use any catalyst, possesses a high purity, high mechanical strength, and good biocompatibility, facilitates bone growth and angiogenesis, requires only 31° C., the highest temperature, during the curing process. It makes the present invention more secure in the biomedical applications.

Abstract: Compositions and methods for producing a manufactured product, a method for making a liquid absorbent, and processes for disposal of flammable liquids with a flue gas desulfurization by-product. The compositions for the manufactured products combine a binder and the by-product. The composition contains a greater percentage by weight of the by-product than the binder. The methods for producing manufactured products include dewatering the gypsum-depleted waste stream to reduce a water content, and forming the manufactured product. The method for making a liquid absorbent includes dewatering, granulating, drying, heating, and packaging a granulated gypsum-depleted composition as the liquid absorbent. The processes for disposal of flammable liquids include distributing a by-product into contact with flammable liquid, absorbing the liquid, transporting, and igniting the flammable liquid. The artificial soils are a combination of by-product and animal waste, human waste, or another bio-solid.

Abstract: The method of production of polymeric construction material from flotation waste originating from copper ore flotation and waste sulfur is described. The method includes mixing of 20-50% by weight of waste sulfur which is combined with 10-50% by weight of flotation waste from flotation of copper ore and 3-25% by weight of waste phosphogypsum as pH regulator. Finally, 10-40% by weight of mineral filler is added. The mixing occurs at a temperature of 130-150 degrees Celsius and the mixing lasts for about 30 minutes with rotational speed of an agitator of 20 rpm.

Abstract: The method of production of polymeric construction material from flotation waste originating from copper ore flotation and waste sulfur is described. The method includes mixing of 20-50% by weight of waste sulfur which is combined with 10-50% by weight of flotation waste from flotation of copper ore and 3-25% by weight of waste phosphogypsum as pH regulator. Finally, 10-40% by weight of mineral filler is added. The mixing occurs at a temperature of 130-150 degrees Celsius and the mixing lasts for about 30 minutes with rotational speed of an agitator of 20 rpm.

Abstract: The preparation of gypsum parts (dihydrate calcium sulfate) with high mechanical strength is obtained with the aid of water layers with nanometric thickness. Calcium sulfate is used, dihydrate as well as hemihydrate, to obtain parts from these two materials, pure or mixed, especially to use in construction work, where the parts are prepared by compressing their slightly humidified powders.

Abstract: The present invention is based on solid-state reaction or reactions in the presence of small amounts of water, between phospho gypsum and agglutinating-neutralizing agents, principally though the application of oxy and hydroxy compounds, without discounting use of the respective carbonates of magnesium, aluminum and principally calcium, in addition to mixtures of these, and the subsequent preparation of self-hardening pellets which facilitate transport and handling. The technological process associated with the invention notably simplifies both the number and type of individual operations, and the preparation of pellets from mixtures of phosphor gypsum; it also reduces energy costs by operating at low temperatures (150°C.) during short periods (1-2 hours), while reducing the quantity of neutralizing agents, and minimizing the volume of water required for the process.

Abstract: The use of water soluble product in construction that is at least partially encapsulated by a water resistant membrane layer, particularly, the use of phosphogypsum, preferably leached phosphogypsum, that is at least partially encapsulated by a geomembrane layer, thus enabling the use of phosphogypsum as a construction material.

Abstract: A method for producing a set gypsum-containing product comprising an interlocking matrix of set gypsum wherein said method comprises applying to said set gypsum one or more enhancing materials selected from the group consisting of phosphoric acid; condensed phosphoric acids, each of which comprises 2 or more phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises 2 or more phosphate units, and monobasic salts or monovalent ions of orthophosphates.

Abstract: A set accelerator for at least one of accelerating the hydration rate and reducing the set time of an aqueous slurry of calcium sulfate hemihydrate is described. The set accelerator consists of a mixture of ground calcium sulfate dihydrate and zinc sulfate material. Aluminum sulfate material is an optional component of the set accelerator. The set accelerator is particularly useful in accelerating the hydration rates of sprayable plasters. A fluid form of the set accelerator may be made by suspending the solids in water. The fluid form is advantageously used in ready mixed setting type joint compounds.

Abstract: A composition of matter for joint or texture compound used in wallboard applications which incorporates an ingredient which has been reclaimed from waste wallboard panel. A method and system for reconstituting the waste wallboard into the joint compound is also provided. Waste wallboard is thereby recycled so that the waste wallboard does not need to be disposed in a landfill.

Abstract: A composition of hydraulic cement is disclosed, having low water demand, high strength and low fragility. The cement comprises finely ground Portland cement clinker, calcium sulfate and a dry modifier containing an organic water reducing component in a weight percent ratio of 91 to 97:2 to 7:0.085 to 4, respectively. The clinker particles comprise three fractions, I, II and III chemically bonded with the organic water reducing component and having respective particle sizes: I--0.05 to 10 mkm in a weight percent of 15.3 to 34.3; II--10.1 to 30 mkm in a weight percent of 37.2 to 77.5; III--30.1 to 80 mkm in a weight percent of 4.2 to 19.6; plus a fraction IV--having a particle size more than 80 mkm in a weight percent less than 4.9 and free of the modifier. The calcium sulfate comprises a fraction of particles of a size 0.5 to 15 mkm, free of the modifier. The dry modifier is chemically bonded with the three clinker fractions in the following weight percent quantities: I--0.045 to 1.7; II--0.02 to 2.

Abstract: This invention relates to a process for preparing ceramic-like materials with specific properties by binding an inorganic filler in the form of a dry composition with a grain size of up to 25 .mu.m containing in the volume ratio 1:0.-1.52 a waste phosphogypsum and magnetite or glass-forming oxides, with an unsaturated polyester resin in an amount of 46-220 volume parts per 100 volume parts of the filler. The use of magnetite makes it poisible to prepare materials with magnetic properties, while glass-foming oxides enable preparing materials effective to absorb an X-radiation of 45-55 keV and a hard radiation of 0.6-125 MeV. When an expanding agent is added to the raw composition according to this invention, an expanded material is obtained, having completely closed pores, particularly useful in the building industry.

Abstract: The process for purifying gypsum suspensions, particularly those formed in a flue gas desulfurizing plant, includes feeding the gypsum suspension (9) to a first hydrocyclone (1), which is operated to produce an underflow (11) with a comparatively high underflow concentration and an overflow fed to a collecting tank (2). The underflow (11) of the first hydrocyclone stage is further diluted to a form another underflow with a lower solids content in a suspension tank (3) and then is fed to a second hydrocyclone stage (4), the overflow of which is also fed to the collecting tank (2). Depending on purity of the gypsum required or attained, the gypsum contained in an underflow (14) of the second hydrocyclone stage (4) is either immediately dewatered and removed or is first fed to one or more hydrocyclone stages, which operate analogously. The combined overflows (15) of the first and second or further hydrocyclone stages are fed from the collecting tank (2) to a third hydrocyclone stage (6).

Abstract: Both the drying and also the removal of the water crystalization take place carefully in a respective fluidized bed apparatus (A, B) without any danger of overheating. This is achieved by a complete homogenous fluidization through indirectly heated hot gas. A substantial quantity of energy is transferred via heat exchanger systems (4 or 12) in the fluidized layer. These are heated by heat carrying media. The constructional design of the fluidized bed apparatuses (A, B) which have a rectangular base outline ensures a narrow dwelltime spectrum and a pronounced temperature/moisture profile without the aid of differentially fluidized chambers. Because of the comparatively cold infeed zone and the careful heating which thereby arise the characteristics of the crystals are favourably influenced. The product is characterized by high quality homogenity. In the case of the calcining of moist gypsum no undesired gypsum modifications arise.

Abstract: This invention relates to an improved process for producing gypsum calcium sulfate dihydrate flakes from powdered gypsum calcium sulfate dihydrate obtained from the desulfurization of flue gas by the wet limestone process. The flakes have sufficient size and strength such that the gypsum calcium sulfate dihydrate can be handled and processed in conventional equipment commonly used by wallboard manufacturers and others in the construction industry, The intermediate calcium sulfate dihydrate from the desulfurization process is dewatered to about 5 to 12% by weight and then compressed into a thin sheet under a compaction or compression load of 4 tons force to 15 tons force per linear inch of sheet width. A linear speed of from 0.5 to 2.5 feet per second is maintained during compaction providing a compaction residence time of from about 0.2 to 1.2 seconds.

Abstract: Disclosed herein is a method for producing plasters that contain chloride contents of less than 0.5% by weight from calcium-containing impure products or residues having a high chloride content (e.g., about 10% or higher based on the total product or residue weight). The method does not require the addition of fly ash, SiO.sub.2 or Al.sub.2 O.sub.3. The method comprises temperature and water-mediated conversion of calcium chloride to calcium oxide in the calcium-containing product or residue using water, steam and/or substances that generate water to obtain calcium oxide and hydrochloric acid; and sulfating calcium components in the product or residue using oxygen and sulfur-containing, largely calcium-free substances. The product so obtained is an anhydride plaster which can optionally be hydrated.

Abstract: Stabilized phosphogypsum-containing compositions with low expansion and high compressive strength characteristics are prepared by admixing phosphogypsum with a cementitious binder having a calculated zero percent tricalcium aluminate content The compositions may contain phosphogypsum and cementitious binder only or they may also include sand or other filler material. The phosphogypsum composition is wetted with water, compacted and allowed to cure. The amount of water added preferably produces a maximum density of the compacted composition.

Abstract: In a process for the conversion of calcium sulfate dihydrate originating in flue gas desulfurization units into an alpha-hemihydrate, a salt solution is used as a medium. The salt solution consists substantially of concentrated scrubbing liquid from the flue gas desulfurization process containing alkali-earth chloride in a chloride concentration of 10% to 60% by weight.

Abstract: A process, and the product produced thereby, for the preparation of a waste solidification material from hardened fluorogypsum as a by-product of the manufacture of hydrofluoric acid by reacting fluorospar with sulfuric acid, removing hydrogen fluoride from the reaction product, slurrying the by-product with water, placing the slurried by-product fluorogypsum in settlement ponds until the fluorogypsum hardens, the hardened fluorogypsum having a pH of greater than about 5 to about 13, including heating the hardened fluorogypsum to evaporate substantially all water physically mixed with the fluorogypsum and further heating the fluorogypsum to reduce the water chemically bound to calcium sulfate in the fluorogypsum to form about 0.5% to about 9% by weight.

Abstract: A method for treating produced gypsum and, in particular, a method for treating flue-gas desulfurization gypsum forms highly active, modifiable gypsum binders of high strength with simultaneously drying, deagglomerating and dehydrating. Pursuant to the invention, produced gypsum (flue-gas desulfurization gypsum), with a particle size ranging up to 200 .mu.m, to which 10% by weight of milled natural gypsum is optionally added, is dehydrated at a material temperature of 335.degree. to 363.degree. K. and at a pressure ranging from 2.5 to 8 kpa, the dehydration being concluded when anhydrite III constitutes 50% to 100% by weight.

Abstract: In a process for preparing calcium sulphate alpha hemihydrate essentially the form of primary crystals, the hemihydrate is milled to specific surface area of 1200 to 4000 cm.sup.2 /g, the fines are removed by screening, and a retarder and liquefier in the form of at least one fruit acid and/or its or their salt(s) are admixed. The product obtained is characterized by delayed onset of rigidity, rapid development of resistance and high resistance, and is used in particular as an injection mortar.

Abstract: A process, and the product produced thereby, for the preparation of a waste solidification material from hardened fluorogypsum as a by-product of the manufacture of hydrofluoric acid by reacting fluorospar with sulfuric acid, removing hydrogen fluoride from the reaction product, slurrying the by-product with water, placing the slurried by-product fluorogypsum in settlement ponds until the fluorogypsum hardens, the hardened fluorogypsum having a pH of about 3 to about 5, including heating the hardened fluorogypsum to evaporate substantially all water physically mixed with the fluorogypsum and further heating the fluorogypsum to reduce the water chemically bound to calcium sulfate in the fluorogypsum to from about 0.5% to about 9% by weight.