244 results about "Anhydrous Calcium Sulfate" patented technology

The invention relates to a method for preparing calcium sulfate crystal whiskers (CaSO4) by using impurity-containing gypsum as a raw material. The method comprises the following steps of: removing main impurities in the raw material which is the low-priced impurity-containing gypsum resource in a mode of roasting, acid-complex leaching and alkaline leaching and simultaneously thinning crystal grains to obtain a superfine dihydrate calcium sulfate precursor which is high in purity and dispersibility; and preparing the anhydrous calcium sulfate crystal whiskers with a length of 20 to 2,000mu m, a diameter of 0.5 to 20 mu m, a length-diameter ratio of 40 to 1,000 and a weight percent content of over 95 percent in a mode of hydrothermal conversion-roasting of a fluxing agent. The method has the advantages of low-priced and easily bought raw materials, simple process, wide application range, and high added value. The calcium sulfate crystal whiskers prepared by the method have a big length-diameter ratio and regular shape, and can be used as reinforcing, heat insulating or flame retardant materials in industries of plastics, rubbers, coatings, papermaking, building materials and the like.

The invention provides a method for producing dehydrated calcium sulfate whisker, comprising: using copper, lead, zinc, aluminium, nickel, cobalt, stannum, non-ferrous metal secondary resource cycle utilizing, calcium nitrate solution produced in treating process of electroplating waste, calcium chloride solution, or mixed water solution of calcium nitrate and calcium chloride as raw material, using sulfuric acid as calcium ion precipitant, adding whisker shape regulating agent, controlling reaction condition, regenerating aqua fortis or hydrochloric acid lixiviant, and simultaneously producing ultralong and big length to diameter ratio calcium sulphate dihydrate whisker. After calcium sulphate dihydrate whisker is deposited from calcium nitrate solution, calcium chloride solution or the mixed solution of calcium nitrate and calcium chloride are deposited, the water solution is translated to be nitric acid solution, hydrochloric acid solution or a mixed solution of nitric acid and hydrochloric acid, returning back to leaching out or treating process for processing non-ferrous metal mineral substance, non-ferrous metal secondary resource or electroplating remove. The calcium sulphate dihydrate whisker is treated by microwave heating, forming calcium sulfate hemihydrate or anhydrous sulphate of calcium after dehydration.

The invention discloses a preparation method of high-reinforcement modified anhydrous calcium sulfate crystal whiskers. The method comprises the following steps that: firstly, limestone powder is added into stirred water to be prepared into calcium salt aqueous emulsion; then, sulfuric acid and crystal modifiers are sequentially added into the stirred water to be prepared into sulfuric acid water solution; next, the calcium salt aqueous emulsion containing 1 mol part of Ca<2+> is added into the sulfuric acid water solution containing 2 mol parts of SO4<2-> with the temperature reaching 100 to 110 DEG C, then, morphology control agents are added, the materials are subjected to stirring and aging for 2 to 3.5 hours under the temperature condition being 110 to 120 DEG C, leaching and washing are carried out, and calcium sulfate hemihydrate crystal whisker wet products are obtained; the calcination drying finally is carried out under the temperature condition higher than 200 DEG C to obtain the anhydrous calcium sulfate crystal whiskers; and then, the surface modification treatment is carried out to finally obtain the high-reinforcement modified anhydrous calcium sulfate crystal whiskers. The preparation method has the advantages that the product quality is high, the cost is low, the preparation process is short, the reaction condition is mild, and in addition, green and environmental-friendly effects can be realized.

The invention relates to a method for preparing baking-free bricks from waste aluminum ash residues. The method has the advantages that the production cost of the baking-free bricks is low, the energy consumption is low, the manufacturing time is short, and the environmental pollution caused by waste aluminum ash residues is reduced. In addition, the baking-free brick prepared by the method disclosed by the invention is high in compressive strength. The raw materials used in the method for preparing the baking-free bricks from the waste aluminum ash residues are waste aluminum ash residues, water-quenched slag, silica fume powder, anhydrous calcium sulfate, silicate cement, slaked lime, sodium chloride, sodium iodide, Al (13) polymer, triethanolamine and water. The method for preparing the baking-free bricks from waste aluminum ash residues comprises the following steps: (1) preparing crushed mixture; (2) preparing a waste aluminum ash residue raw material mixture; (3) preparing a baking-free brick mixture; (4) forming a baking-free brick; and (5) curing the baking-free brick.

A freeze-thaw durable, dimensionally stable, geopolymer composition including: cementitious reactive powder including thermally activated aluminosilicate mineral, aluminate cement preferably selected from at least one of calcium sulfoaluminate cement and calcium aluminate cement, and calcium sulfate selected from at least one of calcium sulfate dihydrate, calcium sulfate hemihydrate, and anhydrous calcium sulfate; alkali metal chemical activator; and a freeze-thaw durability component selected from at least one of air-entraining agent, defoaming agent, and surface active organic polymer; wherein the composition has an air content of about 4% to 20% by volume, more preferably about 4% to 12% by volume, and most preferably about 4% to 8% by volume. The compositions are made from a slurry wherein the water/cementitious reactive powder weight ratio is 0.14 to 0.45:1, preferably 0.16 to 0.35:1, and more preferably 0.18 to 0.25:1. Methods for making the compositions are also disclosed.

This invention relates to a preparation of crystal whisker of calcium sulfate, particularly relating a preparation that produces fibriform mon-crystal of half water or dried gypsum, its concrete steps as following: (1) Adopt hydrothermal synthesis etc technology to compose target agent of crystallizing; (2) Firstly calcium oxide that is technica grade is pretreated, added into reaction vessel to digest at 40-60DEG C, calcarea galacta is obtained; (3) The calcarea galacta that is obtained raises temperature to 40-110DEG C in reaction vessel, add equimolar solution of sulphuric acid, mix 30-60min,add targeting agent of crystallizing in reaction process. Make it react sufficiently, obtain products of required crystal whisker of calcium sulfate by filtering, cleaning, surface treatment and drying. Characteristic of this invention is: add targeting agent of crystallizing that is self produced, control different reactive temperature, obtain crystal whisker of calcium sulfate with different dolicho- diameter ratio, dolicho- diameter of this product is uniform, dolicho- diameter ratio is large, purity of raw material has no strict requirement.

The invention discloses a method for removing impurities and whitening phosphogypsum. The method comprises the following steps: (1) carrying out fineness rough machining on a phosphogypsum raw material; (2) carrying out acid leaching on the phosphogypsum obtained in the step (1) by using sulfuric acid, performing heating and keeping the temperature constant to obtain a material; (3) adding a flotation agent into the material obtained in the step (2), and carrying out flotation concentration separation; (4) feeding the slurry subjected to flotation separation obtained in the step (3) into gravity separation operation for impurity removal to obtain concentrate; and (5) filtering the concentrate obtained in the step (4), washing a filter cake, and drying and crushing the filter cake to obtainthe finished product purified gypsum. According to the method, high-whiteness and high-purity anhydrous calcium sulfate is prepared from phosphogypsum by utilizing a flotation/extraction/gravity separation process in a weakly acidic environment.

The invention belongs to the technical field of whisker preparation and particularly relates to a method for preparing anhydrous calcium sulfate whisker by a one-step hydrothermal process. The method comprises the following steps: (A) putting gypsum in water to prepare a first suspension, stirring and adding a crystal form controller to form slurry, wherein the liquid-solid mass ratio of the water to gypsum is (5.5-30):1, and the molar ratio of the crystal form controller to gypsum is (0.7-5):1; (B) transferring the slurry into a hydrothermal reaction kettle, and stirring for a hydrothermal reaction for 2-10h to obtain a second suspension, wherein the set temperature of the hydrothermal reaction kettle is 170-220 DEG C; and (C) performing solid-liquid separation on the second suspension to obtain a filter cake and filtrate, washing the filter cake and drying to obtain the anhydrous calcium sulfate whisker. According to the preparation method, the anhydrous calcium sulfate whisker can be prepared by a one-step hydrothermal process, and the method is simple; and meanwhile, the problem of low purity and the use of a high-temperature sintering process are avoided, and the production cost is lowered.

The invention discloses a polycaprolactone/calcium sulfate composite material and a preparation method thereof, belonging to the field of macromolecule modification. The method comprises the following steps: utilizing biosurfactant to carry out surface modification on anhydrous calcium sulfate or calcium sulfate whiskers; and adopting a coprecipitation and mould pressing method to prepare anhydrous calcium sulfate or calcium sulfate whiskers reinforced polycaprolactone composite material. The composite material prepared by the method in the invention has the advantages of high mechanical strength and adjustable performance, thereby laying a foundation for the application thereof.

The invention discloses a calcium sulfate-whisker compounded quartz stone board product, which comprises the following materials in parts by weight: 58-75% of particle raw material, 10%-25% of quartz powder, 0.01%-10% of pigment, 0.1%-1% of silane coupling agent, 8%-12% of unsaturated polyester resin, 5%-10% of anhydrous calcium sulfate, and 0.8-2% of curing agent, wherein the particle raw material is one or two selected from quartz particles and glass particles. The product is an environment-friendly novel decoration material which has high property and no radioactive contamination, can be recycled, and has the characteristics of gay colors, high finish degree, uniform color, pressure-resistance and abrasion-resistance, good toughness, compact structure, low water absorption, corrosion-resistance, high strength, impact-resistance, innocuousness and zero radiation, and the like.

The invention relates to a process of producing calcium sulfate crystal whiskers from chloride-containing wastewater generated in chloride process titanium dioxide production. The process comprises the following steps: respectively colleting, clarifying, purifying and filtering chloride-containing wastewater generated in chloride process titanium dioxide production and sodium sulfate-containing wastewater, mixing for reacting, stirring, heating and adding sulfuric acid to adjust the pH value; meanwhile, adding magnesium chloride as a growth substance; placing in a crystallization tank to age and crystallize to obtain calcium sulfate crystals; filtering, and adding H2SO4 to be buffered and heated to be boiled; thermally filtering and washing by deionized water at the same time to obtain calcium sulfate crystal whiskers; feeding to a fluidized bed dryer to be dried and hydrated, and packaging to obtain anhydrous calcium sulfate crystal whiskers. The process is simple and low in cost, and is suitable for industrialized production, so that wastewater is comprehensively utilized.

The invention relates to a plaster base material system for 3D spray bonding fast forming technique, comprising composite base material and auxiliary bonder, where the composite base material is mixed uniformly of plaster powder, bonder, accelerator anhydrous calcium sulphate, dispersant, white carbon black, and intensifier; and the bonder is mixed of water base polyurethane glue, phenol resin, nonionic surface active agent, and alcohol cosolvent, dissolving in deionized water. And the composite base material and auxiliary bonder can completely meet use requirements.

The invention discloses a powder for plugging an air leaking crack. The powder comprises, by mass, 20 to 25 parts of bentonite, 30 to 35 parts of talcum powder, 18 to 20 parts of a super absorbent resin, 12 to 15 parts of sodium alginate and 10 to 15 parts of anhydrous calcium sulfate, and all the above-mentioned components are directly mixed for utilization. The powder is especially applicable to plugging of air leaking cracks in underground coal mines caused by drilling in the process of gas extraction. According to the invention, under the action of positive pressure from a compressed air system and negative pressure from gas extraction, lubricity of talcum powder enables the powder to be transported to a deep crack; when transportation of the powder is stopped, bentonite and the superabsorbent resin absorb water and swell, sodium alginate powder becomes wet when meeting water, hydration of the sodium alginate powder enables the surface of the sodium alginate powder to have viscosity, the sodium alginate powder enables all the components of the powder to bond together to form aggregate and to adhere to crack walls, the powder continues to swell after anhydrous calcium sulfate absorbs water, and anhydrous calcium sulfate turns into hard gypsum at the same time, which enables the hardness of the powder aggregate to be increased and the powder aggregate to firmly plug the crack. All the materials used in the invention are common material on the market, which enables a low cost to be obtained.

The invention discloses a method for preparing calcium sulfate whiskers. The method comprises the following procedures: with limestone as the raw material, grinding, leaching, size mixing, heating, crystallizing, nature determining by the hydrothermal method, steam-pressing, drying and the like. The produced calcium sulfate whiskers have the whitenness, the purity and the content of larger than or equal to 98% and the length-diameter ratio of 50-200. 200-350 kg of anhydrous calcium sulfate whiskers can be produced by each cubic meter of a dihydrate gypsum suspension. The produced whiskers are silky luster and can be used in the aspects of papermaking, coatings, rubber, plastics and the like. As limestone is adopted as the raw material to produce the anhydrous calcium sulfate whiskers, not only is the problem of natural gypsum exhaustion solved, but also optimal resource utilization is realized.

The invention provides a preparation method of anhydrous calcium sulfate whisker. The preparation method specifically comprises the following steps of by taking calcium carbonate or calcium hydroxide as a calcium source, sulfur dioxide as a sulfur source, and ammonium sulfate solution as a medium solution, adding the calcium source into the ammonium sulfate solution, introducing SO2 while agitating; reacting to obtain calcium sulfite whisker; and then filtering and drying with high temperature air to obtain the anhydrous calcium sulfate whisker. The preparation method has the advantages that the reaction condition is mild; the process equipment is simple; the equipment investment is low; the operation is high in flexibility; industrial production can be easily carried out; the whisker is high in length-diameter ratio and reaches 30 to 200 and high in quality; and the preparation method is applicable to independent production and also suitable for co-producing anhydrous calcium sulfate whisker in coal-fired flue gas desulphurization, as well as non-ferrous metal metallurgy, sulfuric acid production and other tail gas treatment.

The invention discloses a surface modification method for calcium sulfate whiskers. The surface modification method comprises steps: anhydrous calcium sulfate whiskers are prepared; a surface modifier solution is prepared; the calcium sulfate whiskers are added slowly into the surface modifier solution with stirring, slow stirring is carried out, and a reaction is carried out; the modified anhydrous calcium sulfate whiskers are subjected to impurity removal processing. The method is simple, the steps are few, raw materials are saved, water processing burden is reduced, the anhydrous calcium sulfate whisker product has good performance, and tensile strength, the tear resistance, the folding strength and the pop strength are high. The solution synthesis method is employed, a calcium-containing industrial tail liquid is reacted with sulfuric acid, calcium sulfate whiskers are prepared, the cleaning utilization problem of calcium ions in the waste liquid is solved, which facilitates to achieve cyclic utilization of raw materials and resources are saved. The yield of the prepared calcium sulfate whiskers is high, the crystal form is structured and the length-to-diameter ratio is high.

The invention discloses an energy-saving wall material produced by using construction solid wastes and a producing method of the wall material, and belongs to the field of construction materials. The energy-saving wall material is produced by using the following raw materials in parts by weight: 50-80 parts of construction solid wastes, 12-20 parts of industrial water, 25-35 parts of portland cement, 0.1-1 part of nanometer nickel borate whiskers, 10-20 parts of boiler coal ash floating beads, 2-4 parts of expanded polystyrene particles, 1-5 parts of basalt fiber, 0.1-2 parts of sodium silicate, 0.2-3 parts of anhydrous calcium sulfate, 1-2 parts of calcium lignosulfonate and 0.1-2 parts of isobutyltriethoxysilane. According to the invention, the problem of construction waste pollution is solved, the wastes are reused, so that resources are saved; the finished product is light in weight, remarkable in heat preservation and good in anti-knock and anti-pressure properties, is a green construction material, and meets national energy conservation and emission reduction requirements; the process is simple, the construction is convenient, the energy consumption in the production process is low, and no pollution is caused to the environment, therefore, the energy-saving wall material and the producing method are energy-saving and environmental protection technologies.

The invention relates to a method for purifying a chromatographic grade organic solvent methyl tertiary butyl ether. The method comprises the following steps of: allowing a raw material, namely methyl tertiary butyl ether to pass through alumina and silica gel so as to remove peroxide impurities, partially dehydrating, further dewatering by using a drying agent, namely anhydrous calcium sulfate, rectifying, filtering, and packaging to obtain a high-purity organic solvent methyl tertiary butyl ether product. In the method, the methyl tertiary butyl ether with the content of between 99.0 and 99.4 percent is taken as the raw material and the alumina and the silica gel are taken as adsorbents for adsorption separation so as to remove organic impurities such as peroxide, partial water and the like from the raw material, anhydrous calcium sulfate is used for further dewatering, and a methyl tertiary butyl ether product with the purity of more than 99.8 percent is obtained by the steps of adsorption, drying, rectification and purification; and various other chromatographic indexes all meet the requirements. The recovery rate is over 93 percent; and the yield approximately reaches over 93 percent.

The invention discloses a calcium ion removing method in the zinc sulfate solution, which is characterized by the following: adopting ultrasound to remove calcium in the zinc sulfate solution; accelerating calcium sulfate from ionic state to calcium; blending removed calcium liquid and inversed-solution with anhydrous calcium sulfate through crystal grower to accelerate growth of calcium sulfate crystal; adopting hydraulic stirrer to reinforce solid-liquid separation; utilizing dense groove structure within dense groove and ultrasonic calcium removing device as ultrasonic calcium groove. The ultrasonic calcium removing device contains ultrasonic crystallizing device, crystal grower, hydraulic stirrer and crystal geosynclinal.

The invention aims to provide alloy plastic, and in particular relates to PC-PPO (Poly Carbonate-Poly-p-Phenylene oxide) alloy plastic, and belongs to the technical field of high molecular materials. The plastic comprises the following components in parts by weight: 100-140 parts of polycarbonate, 40-60 parts of polyphenyl ether, 5-15 parts of a methyl ester-butadiene-styrene copolymer, 5-10 parts of dibutyl phthalate, 10-14 parts of polyvinyl butyral, 3-5 parts of tertiary butyl phenol-formaldehyde resin, 2-4 parts of polydimethylsiloxane, 3-5 parts of polyvinyl ethyl ether, 5-20 parts of aluminum silicate fiber, 15-25 parts of epoxy resin, 5-10 parts of white carbon black, 1-6 parts of anhydrous calcium sulfate, 1-3 parts of nanoscale titanium dioxide, 4-8 parts of polystyrene granules, 6-12 parts of chitosan, 3-5 parts of an antioxygen, 4-12 parts of a coupler and 3-5 parts of an uvioresistant agent. The mechanical property of the plastic corroded by acids and alkalis is decreased to a small extent. After high temperature and high humidity destructive test, the plastic still has good mechanical property which is superior to that of a control sample.