208 results about "Calcium nitrate" patented technology

The invention relates to the technical field of agriculture, in particular to a plant nutrient solution for saline-alkali soil improvement and a preparation method thereof. The invention relates to a preparation method of a plant nutrient solution for improving saline-alkali soil. The preparation method comprises the following steps: preparing NO3-intercalated layered double hydroxides and acid modified calcium-based montmorillonite; preparing humic acid chelated calcium magnesium powder; preparing a binary compound; and preparing the plant nutrient solution. The preparation method comprises the following steps: preparing NO3-intercalated layered double hydroxides from calcium nitrate tetrahydrate and aluminum nitrate nonahydrate, carrying out acid modification on calcium-based montmorillonite by using dilute sulphuric acid, purifying humic acid, and mixing with calcium chloride and magnesium chloride hexahydrate to prepare humic acid chelated calcium magnesium powder. Finally, the three components are added into pig excrement fermentation liquor to prepare a plant nutrient solution, an adsorption-replacement-leaching closed loop can be formed, the desalination and alkali reduction efficiency is remarkably improved, the soil structure is improved, the effect of synergistically improving the saline-alkali soil is achieved, and therefore plant growth is promoted.

The invention relates to the technical field of ammonia control and denitrification of kiln flue gas, in particular to an ammonia control and denitrification method for kiln flue gas for preparing cement from carbide slag based on waste heat utilization. According to the technical scheme, the method comprises the following steps that waste heat cooperative utilization is conducted, specifically, flue gas waste heat is subjected to graded utilization through three waste heat recovery systems, specifically, kiln bypass waste heat utilization is conducted, flue gas is extracted from a kiln bypass dechlorination high-temperature area at about 350 DEG C, and the overall energy consumption of the system is reduced; the atomization effect of the calcium nitrate solution is optimized by adopting the nano dispersing agent, and the sulfur resistance of the modified catalyst is combined, so that efficient and stable denitration reaction is realized, ammonia escape is accurately controlled, finally, the flue gas of the kiln can meet the ultralow emission requirement, and secondary pollution to the environment is greatly reduced; the modular reactor design and the dynamic predictive control technology enhance the adaptability of the system to complex working conditions, meanwhile, fuel consumption is further reduced through waste heat recycling and raw flue gas preheating, the service life of equipment is prolonged, and the operation cost of the system is remarkably reduced.

The invention belongs to the field of cement concrete, and particularly relates to an integrated cementing material special for ultra-high performance concrete and a preparation method of the integrated cementing material. The integrated cementing material comprises fly ash, slag powder, carbide slag, semi-hydrated gypsum, silica fume, a powder reinforcing agent, calcium nitrate and sodium silicate. The production process of the integrated cementing material comprises the following steps: winnowing ultrafine microbeads from fly ash, grinding solid waste powder by a fluidized bed type jet mill, chemically strengthening the powder reinforcing agent, chemically nucleating calcium nitrate and sodium silicate, and mixing the integrated cementing material. The ultra-high performance concrete cementing material is prepared from a high-activity solid waste material, the viscosity of a mixture is reduced by winnowing ultrafine micro-beads, the strength of the cementing material is improved by synergistic reaction of slag powder, carbide slag and semi-hydrated gypsum, and a C-S-H crystal nucleus is formed by chemical reaction of calcium nitrate and sodium silicate to provide active sites, so that the cementing material is prepared. And the cementing material is prepared by combining powder chemical dispersion and integrated mixing, so that the carbon emission and production difficulty of the ultra-high performance concrete are remarkably reduced.

The invention discloses premixed flow-state solidified soil and a preparation method thereof, and the premixed flow-state solidified soil comprises the following components in parts by weight: 100 parts of silty clay; 8 to 15 parts of a curing agent; 48 to 90 parts of water; wherein the curing agent comprises the following components: 10 to 15 parts of sulphoaluminate cement; 40 parts to 55 parts of superfine steel slag powder; 30 to 40 parts of fly ash; 0.5 to 1.5 parts of sodium silicate; 0.1 to 0.3 part of a foaming agent; 0.1 part to 0.2 part of sodium thiocyanate; 0.1 part to 0.2 part of hydroxymethyl cellulose; 0.05 part to 0.2 part of triisopropanolamine; 0.1 part to 0.5 part of calcium nitrate; and 0.5 to 1 part of a polycarboxylic acid water reducing agent. The preparation method of the premixed flow-state solidified soil is suitable for using silty clay as a raw material, and greatly improves the strength, compactness, fluidity and other properties of the premixed flow-state solidified soil.

The invention provides high-transparency rare earth doped fluoride glass and a preparation method thereof, and belongs to the technical field of glass. The calcium fluoride ensures high transparency and chemical stability, the magnesium fluoride improves the ultraviolet transmittance and the mechanical strength, and the barium fluoride optimizes the melting fluidity and the rare earth doping uniformity; aluminum fluoride is added to inhibit crystallization and enhance uniformity, the rare earth element realizes optical function regulation and control, and ammonium fluoride provides a fluorine source and reduces impurities; in a preparation link, quick lime is dedusted and then reacts with pure water in proportion, impurities in a calcium nitrate solution are removed by hydrogen peroxide, uniform growth of calcium carbonate crystal nucleuses is controlled by ammonia water and carbon dioxide, and calcium fluoride is synthesized by hydrofluoric acid in proportion and dried at low temperature after plate-frame pressure filtration and purification; after the raw materials are refined through ball milling, the melting temperature is controlled in stages, impurities, reaction integrity and a microstructure are accurately controlled in the whole process, and finally the high-transparency functional glass is prepared.

The invention provides bridge concrete for extremely cold areas. The bridge concrete is prepared from the following raw materials in parts by weight: 320 to 400 parts of P.O 42.5-grade Portland cement, 9 to 16 parts of a composite anti-freezing agent, 12 to 22 parts of surface modified nano silicon dioxide, 85 to 130 parts of a mineral composite admixture, 950 to 1250 parts of aggregate, 0.7 to 1.6 parts of a polycarboxylic acid type air entraining agent and 1.8 to 5.5 parts of polypropylene fiber, wherein the composite anti-freezing agent is formed by compounding calcium nitrate, calcium formate and triethanolamine according to the ratio of (3.2-5.1): (1.9-4.2): 1, and the effective content of Ca (NO3) 2.4 H2O in the calcium nitrate is greater than or equal to 96%. Compared with the prior art, the composite anti-freezing agent has the following beneficial effects that the calcium nitrate provides early-stage anti-freezing, the calcium formate accelerates low-temperature hydration, and the triethanolamine serves as a dispersing agent to improve the synergistic efficiency of all the components.

The highland barley fertilizer is prepared from the following raw materials in parts by weight: 1000 parts of water, 140 to 160 parts of highland barley rice, 0.5 to 1.0 part of zymophyte, 100 parts of amino acid, 100 parts of magnesium sulfate, 10 to 20 parts of borax, 5 to 10 parts of calcium nitrate tetrahydrate and 100 parts of white sugar. The invention relates to the field of compound microbial fertilizers, in particular to a highland barley fertilizer and a preparation method thereof.The liquid fertilizer is prepared with highland barley as the main raw material, the liquid fertilizer is matched with flora capable of releasing soil fertility, the content of amino acid, calcium and magnesium elements in a fermented product is higher than that of a traditional fertilizer, and the content of amino acid, calcium and magnesium elements is increased while the fertility of soil is increased; the hidden fertility of the soil can be released.

The invention discloses a bottom mud ecological restoration material as well as a preparation method and application thereof. The material is composed of a degradable carrier, a treatment flora and a multifunctional filler. The carrier is porous particles die-cast by corn straws and the like; the treatment flora comprises photosynthetic bacteria, bacillus and nitrifying bacteria; the filler is prepared from non-nitrate type hydrotalcite-like compounds, calcium nitrate, nitrate type hydrotalcite-like compounds and a flocculating agent according to a specific mass ratio. The preparation method comprises the following steps: carrying out pressure casting on the carrier, adsorbing the flora, and rolling the filler to form balls. The restoration method comprises the steps that a river channel is cut off in the dry season to form a closed area, materials are put according to the area ratio of 10: 1 for preliminary restoration, and after standing is conducted for 1-5 days, the materials are put along with water flow according to the area ratio of 2: 1 for deep restoration. Through the physical, chemical and biological synergistic effect, the sediment redox environment can be effectively improved, pollutant release and degradation are promoted, operation is easy and convenient, and the risk of secondary pollution is low.

The invention discloses a flame-retardant wear-resistant conveying belt for a coal mine and a preparation method thereof, and belongs to the technical field of wear-resistant conveying belts. Substances such as calcium nitrate tetrahydrate, ferric nitrate nonahydrate and antimony trioxide are subjected to hydrothermal coprecipitation to obtain multifunctional composite microspheres, the microspheres are aminated through a silane coupling agent KH-550 and then coated with silicon carbide, and coated composite microspheres are obtained; the preparation method comprises the following steps: carrying out graft copolymerization on nitrile rubber, octavinyl silsesquioxane and DOPO acrylate, compounding a quaternary phosphonium salt flame retardant to obtain modified nitrile rubber, carrying out three-stage mixing on the modified nitrile rubber, coated composite microspheres, conductive carbon black and other substances to obtain a rubber coating layer, carrying out double-sided calendering on the rubber coating layer and an epoxy resin plasticized aramid fiber skeleton layer, and carrying out vulcanization molding to obtain the composite material. And finally obtaining the flame-retardant wear-resistant conveying belt for the coal mine. The synergistic effect of high flame retardance, strong wear resistance and static electricity resistance is achieved, and the service life is prolonged.

The invention relates to a method for improving the crystal granularity of calcium nitrate tetrahydrate, and belongs to the technical field of calcium nitrate tetrahydrate crystallization. The invention mainly solves the technical problems of long crystallization time, difficulty in control of the crystallization process, wall hanging of a crystallization tank, non-uniform crystallization granularity and difficulty in drying of crystallized products in the crystallization process of calcium nitrate tetrahydrate at the present stage. According to the technical scheme, the method for improving the crystal granularity of calcium nitrate tetrahydrate comprises the following steps: 1) preparing a reaction solution, namely reacting nitric acid with calcium carbonate, slowly adjusting the pH value, and filtering to obtain the reaction solution; 2) preparing a concentrated solution: performing high-temperature evaporation concentration on the reaction solution in the step 1); (3) carrying out primary cooling on the concentrated solution, namely pumping the concentrated solution in the step (2) into a buffer tank, and pumping the concentrated solution into a crystallizing tank after the concentrated solution is cooled to the material temperature of 60 DEG C; and 4) secondary cooling crystallization: when the temperature of the concentrated solution in the crystallizing tank reaches 38-40 DEG C, adding a small amount of seed crystals (not easy to add more) so as to achieve a seeding effect, and after the temperature of the material liquid in the crystallizing tank reaches 30-37 DEG C, carrying out solid-liquid separation by a centrifugal machine. The method has the advantages of simplicity in operation, short cooling time, large and uniform crystal granularity and the like.

The present disclosure provides a method for producing calcium nitrate from calcium lactate. The method comprises: a) providing an aqueous calcium lactate solution; b) adding phosphoric acid to the aqueous calcium lactate solution, thereby producing a first composition comprising lactic acid and calcium phosphate; c) separating the calcium phosphate from the first composition, thereby obtaining an aqueous lactic acid solution and a second solid composition comprising calcium phosphate; d) reacting the second solid composition with nitric acid, thereby obtaining a third composition comprising phosphoric acid and calcium nitrate; and e) separating the calcium nitrate from the third composition, thereby obtaining an aqueous phosphoric acid solution and a solid calcium nitrate composition.

The invention discloses a calcium nitrate slow-release filler for strengthening restoration of black and odorous bottom mud of a river channel and a preparation method of the calcium nitrate slow-release filler. The calcium nitrate slow-release filler is prepared by physically mixing Ca (NO3) 2.4 H2O, PVA (Polyvinyl Alcohol) and sodium carboxymethyl cellulose. The calcium nitrate slow-release filler disclosed by the invention not only can controllably slowly release calcium nitrate and prevent the calcium nitrate from quickly escaping to overlying water to cause secondary pollution after being put into the bottom mud, but also can provide an electron acceptor for the bottom mud, effectively remove sulfide and ferrous ions in the black and odorous bottom mud and relieve the black and odorous phenomenon of the bottom mud in urban river channels; the method has a wide application prospect in the restoration of the black and odorous bottom mud of the river channel.

The invention discloses a composite thermal insulation material suitable for A-grade fire prevention and a preparation method thereof, relates to the technical field of building composite materials, and solves the problem that an existing building material is difficult to meet the comprehensive requirements of fire prevention, thermal insulation and freezing resistance in alpine regions. Comprising quick-hardening sulphoaluminate cement, silica powder, MDI-50, polyether polyol, silane coupling agent modified basalt fibers, silane coupling agent modified polyvinyl alcohol fibers, triethanolamine, a thickening foam stabilizer, fatty alcohol ether sodium sulfate and 1-1.5 parts of a calcium nitrite antifreezing agent. The thickening foam stabilizer is a compound of hydroxypropyl methyl cellulose and polyether modified silicone oil. The material can be prepared without special construction equipment, can be accurately adapted to construction scenes of traffic inconvenience and energy shortage in alpine regions, and has extremely high engineering application value and popularization prospect.

The application provides an in-situ liquid gel-forming water-retaining agent and a preparation method and application thereof. The water-retaining agent is composed of A component and B component which are applied in steps. The A component contains an aqueous solution of a natural modified polymer, and the natural modified polymer is selected from one or two of carboxymethyl chitosan, carboxymethyl cellulose or a sodium salt thereof. The B component contains an aqueous solution of a cationic crosslinking agent, and the cationic crosslinking agent is selected from one or more cations of copper nitrate, iron nitrate, zinc nitrate, manganese nitrate, chitosan quaternary ammonium salt, calcium nitrate and magnesium nitrate. The water-retaining agent can realize the integrated functions of slow release of trace elements, water retention, soil improvement and precise nutrition supply. Furthermore, the water-retaining agent is applied to crop growth in combination with the "step-by-step drip irrigation and in-situ gel formation" technology, so that the agronomic characters of crops can be significantly improved.

The invention discloses a method for comprehensively recycling yellow phosphorus slag of an electric furnace, and belongs to the technical field of chemical engineering. Comprising the following steps: grinding slag, adding nitric acid in proportion, reacting dicalcium silicate in the slag with nitric acid to generate calcium nitrate and silicon slag, and reacting calcium nitrate with ammonium carbonate to prepare an ammonium nitrate product and a calcium carbonate product; and washing and separating the silicon slag to obtain orthosilicic acid, returning one part of orthosilicic acid to be re-blended with the phosphate ore to enter the furnace so as to recycle the slag, and calcining the rest part of orthosilicic acid to obtain a white carbon black product. The use amount of silica is reduced, mineral resources of silica are saved, and the use amount of silica produced from yellow phosphorus reaches self-balance.

The invention relates to the technical field of metal surface treatment, in particular to a high-salt-spray-corrosion-resistance workpiece surface phosphating treatment method. The method comprises the following working procedures of ultrasonic oil removal, water washing, water washing, activation, dipping phosphorization, water washing, water washing, ultrasonic hot water washing and drying, and dipping phosphorization refers to that an activated workpiece is put into a phosphating solution to be subjected to phosphating treatment; the phosphating solution comprises the following components: 5-8 g / L of organic phosphonic acid, 30-40 g / L of zinc dihydrogen phosphate, 50-55 g / L of calcium nitrate, 2-4 g / L of sodium m-nitrobenzenesulfonate, 1-2 g / L of an accelerant, 0.5-0.8 g / L of a surfactant, 1-3 g / L of sodium molybdate, 2-4 g / L of citric acid and 0.2-0.44 g / L of rare earth salt. Through low-temperature high-efficiency process design and multi-component collaborative innovation, breakthrough is achieved in the aspects of compactness, corrosion resistance, adhesive force and other core performance of the phosphating film, the environment friendliness and economical efficiency are both achieved, and a new solution is provided for metal corrosion prevention in the fields of automobiles, ships, electronics and the like.

This application relates to the field of wastewater treatment, specifically disclosing a sulfur autotrophic denitrification process; including the following specific steps: S1: After adjusting the pH of calcium nitrate tetrahydrate solution and ammonium dihydrogen phosphate solution to alkaline, triethanolamine is added dropwise to the calcium nitrate solution, followed by the addition of ammonium dihydrogen phosphate solution to form a reaction solution. The pH of the reaction solution is maintained at alkaline, and the reaction is heated. After filtration, washing, and drying, hydroxyapatite powder is obtained. The hydroxyapatite powder is mixed with a foaming agent, foam stabilizer, and adhesive, pressed into shape, and sintered to obtain a porous ceramic carrier; S2: The porous ceramic carrier, ground inorganic energy material, and denitrifying bacteria are added to the wastewater to be treated, mixed, and subjected to aeration treatment. The inorganic energy material is replenished periodically to complete the process. The sulfur autotrophic denitrification process used in this application has high denitrification efficiency, and no replenishment of denitrifying bacteria is required during the process.

The invention discloses fibrous ettringite, a light cement aerogel material for a pipeline lining based on the fibrous ettringite and a preparation method of the light cement aerogel material. The light cement aerogel material for the pipeline lining is prepared from a solution obtained by mixing and stirring fibrous ettringite, cement, an adhesive, a dispersing agent, a hydrophobic component, a foaming component and water through a directional freezing technology, wherein the fibrous ettringite is prepared by heating and stirring a calcium nitrate solution, an aluminum sulfate solution and a sodium hydroxide solution. According to the invention, ettringite which can be uniformly dispersed is synthesized by a ligand-free thermal injection method, and the ettringite, cement and an adhesive raw material are subjected to freezing pore-forming by adopting a directional freezing technology, so that the aerogel material with a special organic-inorganic framework directional ordered pore structure has the characteristics of light weight, high strength, flame retardance and the like; and the overall performance of the pipeline lining material can be improved.

The present invention discloses a method for preparing ultrafine particles of low-dielectric ceramic materials for 6G, relates to the technical field of dielectric ceramic materials, and belongs to patent classification number C04B35 / 00. The specific preparation method is to first prepare a sol using tetraethyl orthosilicate, calcium nitrate, magnesium nitrate, aluminum isopropylate, zirconium oxychloride and lithium nitrate, heat the sol and let it stand for gelation, then use supercritical CO2 to dry, obtain aerogel, heat and reduce calcination to obtain (Ca, Mg) SiO3-ZrO2 nanopowder, and use atomic layer deposition technology to coat a TiO2 layer on the surface of the nanopowder to obtain ultrafine particles of dielectric ceramic materials. The ceramic particles prepared by the present invention not only have a low dielectric constant, but also have a smaller particle size and a higher density under low-temperature sintering.

The invention relates to the technical field of chemical production, and provides a gypsum-based inorganic cementing material and a preparation method and application thereof.The gypsum-based inorganic cementing material is prepared from, by mass, 30%-50% of anhydrous gypsum, 20%-30% of semi-hydrated gypsum, 5%-10% of quick lime and 5%-30% of aluminum sulfate or alums, and the sum of the mass percentages of all the components is 100%. Calcium formate or calcium nitrate accounts for 5-10%, copperas accounts for 0-10%, and sodium metaaluminate accounts for 0-10%. According to the gypsum-based inorganic cementing material as well as the preparation method and the application thereof provided by the technical scheme, the core technical bottleneck of environmental problems caused by massive stockpiling of industrial byproduct gypsum and poor water resistance of products is effectively solved, and high-added-value resource utilization of the industrial byproduct gypsum is realized.

The invention relates to the technical field of fertilizers, in particular to a nutrient polymerized polyglutamic acid compound fertilizer and a preparation method thereof, and the nutrient polymerized polyglutamic acid compound fertilizer comprises the following raw materials in parts by weight: 6-10 parts of gamma-polyglutamic acid, 25-30 parts of filler, 20-25 parts of a nitrogen source, 12-15 parts of a phosphorus source, 10-14 parts of a potassium source, 4-6 parts of a compound additive and 0.1-0.2 part of a fungicide. In the preparation of the granules, the humic acid powder is coated by a first treating agent prepared from the soluble starch, the salicylic acid, the sodium alginate and the like, so that the activity of the humic acid is effectively protected, and meanwhile, the mechanical strength and the slow-release characteristic of the granules are further enhanced by a second treating agent prepared from the components such as the chitosan and the fulvic acid through a chelation cross-linking effect; in addition, chondroitin sulfate, calcium nitrate, ammonium molybdate and molasses in the batch jointly provide medium trace elements and organic carbon sources, and synchronous release and efficient utilization of nutrients after the fertilizer is applied to soil are ensured.

The invention provides a method for improving combustibility of cigar tobacco leaves and ash gray and application of the method, and belongs to the technical field of tobacco production processes. The method comprises the following steps: harvesting naturally mature fresh raw tobacco leaves, cutting the petiole ends of the raw tobacco leaves into wedge shapes, and soaking the petiole ends of the raw tobacco leaves in a composite synergist mother solution for 1-2 days; and airing the raw tobacco leaves subjected to stem soaking to obtain the cigar raw tobacco leaves. The composite synergist mother liquor comprises the following components in percentage by mass: 5-8% of water-soluble sylvite, 6-9% of water-soluble calcium salt and 7-10% of water-soluble magnesium salt. The water-soluble potassium salt is monopotassium phosphate or potassium nitrate; the water-soluble calcium salt is calcium nitrate; the water-soluble magnesium salt is magnesium nitrate, magnesium sulfate or chelated magnesium. By means of the method, the smoldering time of the tobacco leaves can be remarkably prolonged, and cigarette ash becomes white.

The application discloses a concrete superfine powder admixture early strength type additive and a preparation method thereof. The application adopts the modified silicon dioxide filter sludge prepared from silicon dioxide filter sludge, dilute hydrochloric acid and nano alpha-Fe2O3 precursor, and then mixes the modified silicon dioxide filter sludge with triethanolamine, calcium nitrate, calcium hydroxide and a polycarboxylic acid high-performance water reducing agent to prepare the concrete admixture early strength type additive. After the modification of the nano alpha-Fe2O3 precursor, the surface activity of the silicon oxide compound in the filter sludge is improved, so that the silicon oxide compound can participate in the cement hydration reaction and the early strength is improved. Further, the synthesis of the early strength type calcium silicate increases the diversity of the early strength improvement of the cement, and the early strength agent effect of sodium sulfate existing in the filter sludge is fully utilized. The three early strength effects are combined with each other, and the potential functionality of the filter sludge in producing the early strength effect is fully tapped.

The invention discloses a method for treating aquaculture wastewater based on a persulfate advanced oxidation technology, which comprises the following steps: (1) putting prepared secondary modified zeolite into a polycarboxylate superplasticizer, stirring, then adding a solution containing Fe < 2 + > and / or Fe < 3 + >, carrying out ultrasonic treatment, then separating out a solid product, and calcining in a protective atmosphere to obtain a modified zeolite precursor; and then cooling to room temperature to obtain the three-stage modified zeolite. And (2) adding the mixture into alkali liquor for heating treatment, then mixing the obtained solid product with a calcium nitrate solution for hydrothermal reaction, and then washing and drying the obtained solid product to obtain the heterogeneous catalyst. And (3) adding persulfate and a heterogeneous catalyst into the breeding wastewater for wastewater treatment. Heterogeneous catalysis is adopted to promote persulfate to release free radicals, so that the problem of waste caused by difficulty in recycling a catalyst is solved, and the problem of secondary pollution of wastewater caused by the catalyst is favorably avoided.

The invention discloses a carbon-based biological liquid organic water-soluble fertilizer as well as a preparation method and application thereof, and belongs to the technical field of biological organic fertilizers. The water-soluble fertilizer comprises the following raw materials in parts by weight: 15-25 parts of a seaweed extract, 10-15 parts of potassium fulvate, 5-10 parts of a compound microbial agent, 3-5 parts of potassium dihydrogen phosphate, 2-4 parts of potassium nitrate, 2-3 parts of urea, 2-3 parts of calcium nitrate, 1-2 parts of magnesium sulfate heptahydrate, 1-1.5 parts of a trace element-containing substance, 1-2 parts of sodium dodecyl benzene sulfonate and 0.5-1 part of potassium sorbate. The total amount of the components is 100 parts. According to the invention, three strains such as pseudomonas sevivaldi, bacillus pumila and bacillus thuringiensis are screened to play roles in three dimensions of promoting growth, improving rhizosphere environment and preventing and treating diseases and insect pests respectively, and are combined with organic components such as seaweed extract and potassium fulvate in the fertilizer and other components, so that the fertilizer has a good application prospect. A comprehensive system of nutrition, growth promotion, disease resistance and quality improvement is formed, and the yield and quality of grapes are remarkably improved.

A method for large-scale synthesis of calcium lanthanum sulfide (CLS) powders and the resulting optical-grade materials are disclosed. The CLS powders, including compositions such as CaLa2S4, CaLa2.0-2.7S4.0-5.05, and CaLa18S28, are produced via an aqueous combustion process utilizing lanthanum nitrate, calcium nitrate, and thioacetamide as a sulfur donor. The exothermic combustion step generates localized high temperatures, forming nanostructured CLS powders with uniform stoichiometry and phase purity without the need for prolonged calcination. The powders exhibit excellent sinterability and can be consolidated by hot isostatic pressing into windows, domes, and lenses with infrared transmittance exceeding 50% in the 8-14 μm range and high mechanical strength. The process is scalable, energy-efficient, and environmentally friendly, enabling cost-effective production of infrared optical components for missile and defense applications.

The present invention belongs to the technical field of soil remediation, and discloses a magnetic soil remediation microsphere and its preparation, application and recycling method. First, hydrotalcite, magnetic iron oxide and sodium alginate are made into a mixed solution, and then the mixed solution is added dropwise to a calcium chloride solution for solidification to obtain magnetic soil remediation microspheres. The magnetic soil remediation microspheres are used to repair chromium-contaminated soil. After the remediation is completed, the used magnetic soil remediation microspheres in the soil are recovered by the action of a magnetic field, and then added to a calcium nitrate solution for regeneration to obtain regenerated magnetic soil remediation microspheres. The preparation method of the magnetic soil remediation microspheres of the present invention is simple, and when applied to chromium-contaminated soil, it can achieve a good treatment effect in a short time, and is easy to recycle and regenerate, and has the characteristics of being recyclable and regenerated multiple times. It has broad market application prospects in the field of chromium-contaminated soil remediation.

This invention discloses a cow dung biochar composite material for saline-alkali land improvement, its preparation method, and its uses, belonging to the field of cow dung material processing technology. It includes the following steps: (1) air-drying cow dung, then performing oxygen-limited pyrolysis, cooling, and pulverizing to obtain raw cow dung biochar; (2) mixing the raw cow dung biochar with calcium nitrate solution and then stirring for modification; (3) after modification, drying and performing oxygen-limited pyrolysis, cooling, and pulverizing to obtain the cow dung biochar composite material. This invention uses widely available raw materials and an easy-to-operate method to produce a calcium nitrate-modified cow dung biochar composite material that can be widely promoted and is inexpensive, and the preparation process generates no pollutants. The prepared composite material can lower the pH of saline-alkali land, improve the physical and chemical properties of the soil, and reduce the sodium content in the soil. + It has a stronger adsorption capacity, reduces soil salinity, increases soil nitrate nitrogen content, promotes plant growth, and achieves the effect of recycling livestock waste.

The invention relates to the technical field of aerogel microspheres, and discloses hydroxyapatite aerogel microspheres and a preparation method and application thereof.The method comprises the steps that triethyl phosphite and water are subjected to a first contact reaction, and a mixture I is obtained; the mixture I is sequentially mixed with an anionic surfactant, an ethanol solution containing an inorganic calcium source and an alkaline substance for a reaction, and hydroxyapatite aerogel microspheres are obtained; the adding amount of the alkaline substance is controlled, so that the initial pH value of the reaction system is 8-10; the inorganic calcium source is calcium nitrate and / or calcium hydrogen nitrate, and the molar ratio of the calcium element in the inorganic calcium source to the phosphorus element in the triethyl phosphite is 5: (2-4). The hydroxyapatite aerogel spherical particles are prepared by utilizing an emulsion method, and the prepared aerogel microspheres are high in specific surface area, are more regular and uniform, are low in breakage rate and have the advantage of being easier to industrialize.

The application provides a method for preparing calcium thiocyanate by using desulfurization waste liquid, calcium nitrate and ammonium thiocyanate are respectively dissolved into 30-50% solution, the calcium nitrate solution is slowly dropped into the hot ammonium thiocyanate solution under the conditions of heating and stirring, under the heating state, the double decomposition reaction occurs to generate calcium thiocyanate and ammonium nitrate, with the continuous heating and the evaporation of water, the concentration of calcium thiocyanate gradually increases, the ammonium nitrate is heated and decomposed to generate nitrogen oxide and ammonia gas, the generated process gas rich in nitrogen oxide and ammonia gas is condensed and introduced into the coking ammonia removal and denitration section for treatment, and finally the evaporation and concentration obtain about 50% calcium thiocyanate product. The method uses industrial waste to provide raw materials, and the production cost is low; the process tail gas generated in the reaction only needs to be treated by the existing ammonia removal and denitration device of the coking enterprise, without increasing additional equipment, thereby saving the expenditure; and the method has environmental protection benefit, social benefit and economic benefit.