47 results about "Nitrate hydrate" patented technology

The invention relates to active carbon used for absorbing and removing sulfides in gasoline, and a preparation method thereof. The active carbon is composed of the following components in percentage by weight: 40-70% of petroleum coke, 10-50% of coal, 10-30% of adhesive, 0.1-10% of pore forming agent and 0.1-10% of amodifier, wherein the ash content of the petroleum coke is less than 1%; the coalis anthracite or bituminous coal with volatile content less than 35%; the adhesive is one of or the mixture of coal pitch, coal tar, vacuum residue, coked condensed oil, ethylene cracked residue, catalytic slurry, petroleum pitch and petroleum pitch oxide; the pore forming agent is one of or the mixture of carbon black containing active functional groups and active elements, furfural residue, ferrocene, furfuryl alcohol and potassium; and the modifier is a hydrate nitrate of Cr, Fe, Co, Ni, Mo, Ti, Cu or Zn. The active carbon has the characteristics of low ash content, high strength, high selectivity, excellent adsorption performance and the like.

A method is disclosed for synthesizing a crystalline metal oxide powder material containing two or more uniformly distributed metal elements. Crystalline, water containing, oxygen containing inorganic acid salts of the metals are heated to liquefy the salts. The apparent solution contains a uniform mixture of the metal elements. The water is removed from the liquid and the resulting powder calcined in air to decompose the acid salts to a mixed metal crystalline oxide. The method is particularly useful to make doped LiNiO2 type crystals using hydrated nitrate or nitrite salts of Li, Ni and the dopant elements. Examples of useful salts are LiNO3.H2O, Ni(NO3)2.6H2O, Co(NO3)2.6H2O, Al(NO3)3.9H2O, and Mg(NO3)2.6H2O.

The invention discloses a graphene / double-metal oxide composite material, heavy metal ion adsorption of the graphene / double-metal oxide composite material and a preparation method of the graphene / double-metal oxide composite material. The composite material is prepared from a divalent nitrate hydrate, a ferric nitrate hydrate, a basic compound and graphene oxide. According to the composite material disclosed by the invention, the main raw materials are low in cost, and the preparation method is simpler and is easier to control. The composite material has a strong Cr(VI) adsorption function and can be used repeatedly, so that the cost performance is high.

The invention relates to a method and a device for preparing rare earth doping nano-titania photocatalyst with supercritical carbon dioxide process. The method comprises the following specific steps: adding titanium alkoxide, absolute ethyl alcohol and rare earth element nitrate hydrate in a reaction kettle for stirring and dissolving; pumping high purity CO2 in the reaction kettle at the temperature of 110-150 DEG C under the pressure of 80-500 bar; adding deionized water in a deionized water dissolving kettle and raising the temperature till 110-150 DEG C; then pumping high purity CO2 in the deionized water dissolving kettle under the pressure of 80-500 bar, and causing the pressure difference between the deionized water dissolving kettle and the reaction kettle to be kept at 10-30 bar; flowing supercritical CO2 fluid doped with deionized water in the reaction kettle at the temperature of 110-150 DEG C and under the pressure of 80-500 bar, stirring for 4-24h for reaction; and after the reaction is finished, drying obtained products after being washed, and grinding the products so as to obtain the rare earth doping nano-titania photocatalyst.

The invention discloses a preparation method of a nano-fiber boehmite material. The nano-fiber boehmite material is synthesized by a one-step hydrothermal process. The preparation method comprises the following steps of adding a nitrate hydrate mixture of aluminum nitrate nonahydrate and magnesium nitrate hexahydrate into deionized water; adding hexamethylenetetramine and a surfactant; mixing and performing a hydrothermal reaction at 100-145 DEG C; filtering, washing and drying to obtain nano-fiber boehmite with controllable appearance and good dispersity. The preparation method has the characteristics of short time and simplicity and convenience, and the prepared boehmite is applicable to the fields such as water treatment filtering materials, precursors for preparing pure-aluminum and aluminum oxide materials, and the like.

The invention relates to silicate and provides a preparation method for hollow silicate, in particular to a simple and effective method for preparing hollow silicate under solvothermal conditions. The method comprises the following steps: synthesizing silicon dioxide nanospheres: mixing tetraethoxysilane, water, ammonia water and ethanol by volume ratio of 1: (0.25-2): (0.25-4): (4.25-68) of tetraethoxysilane to water to ammonia water to ethanol, and washing the obtained products after reaction to obtain the silicon dioxide nanospheres; and adding the silicon dioxide nanospheres, urea, dihydrate-2-hydroxy-5-sulfo-benzoicacid and nitrate hexahydrate in water and ethanol, and cooling the obtained solid product to room temperature after reaction, and washing the obtained solid product to obtain the target product, i.e. the hollow silicate.

The invention relates to a preparation method of aluminum alloy cobalt salt chemical conversion coating treating fluid, belonging to the field of aluminum alloy surface treatment. A porous chemical conversion coating formed by treating aluminum alloy through treating fluid has the characteristics of no chromium, environment friendliness, and good corrosion resistance property, and the like, the treating fluid is prepared from cobalt salt, oxidant, ligand and water, wherein per liter of cobalt salt chemical conversion treating fluid contains the following compositions by weight: 20-50g of cobalt salt, 1-50g of an oxidant, and 2-7g of ligand, and the PH value of the treating fluid ranges from 3 to 4; the cobalt salt is selected from one or two of cobalt-nitrate hydrate and cobalt-chloride hydrate; the oxidant is selected from one or more of lithium permanganate, sodium permanganate, ammonia permanganate and calcium permanganate; and the ligand is selected from one or two of sodium nitrite or sodium acetate.

The invention discloses a preparation method of an in-situ synthesis ZTA particle reinforced steel-based configuration composite material, and belongs to the technical field of metal-based composite materials. The preparation method comprises the steps of preparing transparent sol by taking aluminum nitrate nonahydrate, zirconyl nitrate hydrate and the like as raw materials; adding steel-based powder into the sol for liquid-solid doping, stirring until solidification, and sequentially carrying out vacuum drying and reduction on ZTA / steel-iron mixed powder; and filling the honeycomb walls of a honeycomb-shaped mold with the ZTA / steel mixed powder, filling honeycomb holes of the honeycomb-shaped mold with the steel-based powder, and obtaining the in-situ synthesis ZTA ceramic particle reinforced steel-based honeycomb structure composite material after pressing and sintering. ZTA ceramic is generated in situ, the surfaces of ceramic particles are free of pollution, the compatibility with a steel matrix is good, and the interface bonding strength is high; and the honeycomb walls are composed of the composite areas with high hardness, the abrasion effect borne by the honeycomb holes with low hardness can be remarkably reduced, the abrasion resistance is improved by more than three times compared with a traditional steel material, and wide application prospects are achieved.

The invention discloses a bimetallic MOFs material for CO2 capture and a preparation method and application thereof, and belongs to the technical field of material science and chemical engineering. The bimetallic MOFs material is prepared by taking copper nitrate hydrate and nitrate hydrate of transition metal as two metal central ion sources and trimesic acid as a ligand material. The specific preparation method comprises the steps that copper nitrate hydrate, nitrate hydrate of transition metal and trimesic acid are dissolved in a solvent to prepare solutions, the solutions are mixed and then subjected to a hydrothermal reaction, and centrifugation, washing and drying are carried out to obtain the bimetallic MOFs material. The bimetallic MOFs material is tableted and sieved, and a 20-40-mesh material is taken; degassing treatment is carried out at normal pressure; and adsorption is carried out in an atmosphere containing CO2 gas at normal pressure. Compared with an original material HKUST-1, the CO2 adsorption capacity of the bimetallic MOFs material can be remarkably improved through the bimetallic synergistic effect of the bimetallic MOFs material.

The invention provides a preparation method of an rGO-LaFeO3 nanometer compound material. The preparation method specifically includes the steps of adopting a lanthanum nitrate hydrate, a ferric nitrate hydrate and citric acid as raw materials and making the raw materials subjected to a hydrothermal reaction and calcination treatment to obtain lanthanum ferrite nanometer microspheres; adopting graphene oxide and APTES as raw materials and using the raw materials for compounding sheet-like reduced graphene oxide (rGO) on the surfaces of the lanthanum ferrite nanometer microspheres. The preparation method is simple in process, and the rGO-LaFeO3 nanometer compound material is obtained at last. The rGO-LaFeO3 nanometer compound material has high sensitivity on triethylamine, is fast in response and recovery and can be applied to the field of triethylamine gas sensors, and therefore a novel gas-sensing material with high sensitivity is obtained.

A melt of nickel nitrate hydrate is introduced as droplets or liquid flow into a heated reaction vessel and thermally decomposed in a gas phase at a temperature of 1200° C. or more and at an oxygen partial pressure equal to or below the equilibrium oxygen pressure of nickel-nickel oxide at that temperature to manufacture a highly crystalline fine nickel powder with an extremely narrow particle size distribution. The oxygen partial pressure during the thermal decomposition is preferably 10−2 Pa or less, and a metal other than nickel, a semimetal and / or a compound of these may be added to the nickel nitrate hydrate melt to manufacture a highly crystalline nickel alloy powder or highly crystalline nickel composite powder. The resultant powder is suited in particular to thick film pastes such as conductor pastes for manufacturing ceramic multilayer electronic components.

The invention relates to a method for preparing Portland cement clinker. The method comprises the following steps: proportionally mixing tetraethoxysilane, a calcium nitrate hydrate, an aluminium nitrate hydrate, a ferric nitrate hydrate, ethanol, nitric acid, hexamethylenetetramine, acetylacetone, deionized water and the like uniformly to obtain four kinds of mixed liquid, fully stirring the four kinds of mixed liquid respectively at the temperature of 50-70 DEG C until proper viscosity to obtain monomineral sols of the Portland cement clinker, then mixing the four monomineral sols in a massratio of (36-55):(24-40):(11-19):(20-31), ageing the mixture to form gel, carrying out heat treatment on the gel at the temperature of 1150-1200 DEG C for 4-6 hours and cooling the gel to the room temperature, thus obtaining the Portland cement clinker. Compared with the prior art, the method has the following advantages: the preparation process is simple; the reaction process is easy to control;and the product has high uniformity and purity and can be fired at the temperature lower than the temperature in the traditional methods.

The invention discloses a method of using nitrate hydrate to prepare a bisphosphonate nitro compound. The method includes: in an organic solvent, taking nitrate hydrate as a nitro source, an oxygen-containing compound as an additive and 1, 6-diyne as a substrate for nitration-cyclization-oxidation tandem reaction, and performing aftertreatment after reaction is finished to obtain the bisphosphonate nitro compound. The compound is synthesized by direct nitration of 1, 6-diyne; the method is simple, and the nitrate hydrate is used as the nitro source, so that the compound is low in cost, easy toobtain, safe and stable. The method can be used for synthesizing a series of bisphosphonate nitro compounds, and nitric oxide release ability and drug activity of synthesized products can be furtherstudied.

The invention provides a method for preparing aldehydes or ketones through alcohol oxidation. According to the method, alcohol is oxidized into aldehyde or ketone by taking water as a solvent, iron nitrate hydrate (Fe (NO3)3.9H2O), 4-hydroxy-2,2,6,6-tetramethylpiperidine oxide (4-OH-TEMPO) and carboxylic acid as catalysts and oxygen or air as an oxidizing agent. Compared with the prior art, the method provided by the invention takes water as a solvent, avoids the use of polluting halogenated hydrocarbon or strong cancerogen sodium nitrite (NaNO2), is more environment-friendly, greatly reduces the cost, and is a method suitable for industrial production.

A melt of nickel nitrate hydrate is introduced as droplets or liquid flow into a heated reaction vessel and thermally decomposed in a gas phase at a temperature of 1200° C. or more and at an oxygen partial pressure equal to or below the equilibrium oxygen pressure of nickel-nickel oxide at that temperature to manufacture a highly crystalline fine nickel powder with an extremely narrow particle size distribution. The oxygen partial pressure during the thermal decomposition is preferably 10−2 Pa or less, and a metal other than nickel, a semimetal and / or a compound of these may be added to the nickel nitrate hydrate melt to manufacture a highly crystalline nickel alloy powder or highly crystalline nickel composite powder. The resultant powder is suited in particular to thick film pastes such as conductor pastes for manufacturing ceramic multilayer electronic components.

The invention discloses an ABO3 type double perovskite LaCoyNi1-yO3 nanorod electro-catalytic material and a preparation method thereof, and belongs to the technical field of electro-catalytic materials. The electro-catalytic material is prepared from cobalt nitrate hydrate, lanthanum nitrate hydrate, nickel formate hydrate and potassium hydroxide through the processes of coprecipitation, hydrothermal treatment, roasting, acid pickling and the like. The prepared LaCoyNi1-yO3 nanorod has a special nanostructure, so that more electrochemical active sites can be released, and more excellent electrocatalytic activity is shown. Meanwhile, optimization of the catalytic activity of the LaCoyNi1-yO3 nanorod is realized by regulating and controlling the ratio of the catalytic center metal on the B site. The ABO3 type double perovskite LaCoyNi1-yO3 nanorod is moderate in raw material price, simple to prepare and excellent in performance, has a good commercialization prospect, is an excellent electro-catalysis material, and can be used in the field of new energy conversion such as ammonia production through electro-catalysis nitrogen reduction.

The invention provides lanthanum aluminate-doped fuel cell electrolyte and a preparation method. The preparation method comprises the following steps: mixing hydrated nitrate of lanthanum, hydrated nitrate of aluminum, a doping element A, a doping element B, acetylacetone, isopropyl alcohol and a methylcellulose aqueous solution to prepare a La1-xAxAlyB1-yO3 type compound precursor, coating the surface of a substrate layer with the La1-xAxAlyB1-yO3 type compound precursor to form a thin film precursor, and performing high-temperature sintering to prepare a cubic perovskite type doped lanthanumaluminate thin film, namely obtaining the fuel cell electrolyte. According to the method provided by the invention, an octahedral interstice inside a crystal is enlarged; an interstice conduction channel similar to an apatite structure is formed inside a crystal lattice, and the number of oxygen vacancies is increased by doping, so that the transmission efficiency of electrolyte oxygen ions is effectively improved; the thermodynamic stability is high, and the working temperature is relatively low; meanwhile, the preparation process is simple; the used raw materials are low in cost, so that the anthanum aluminate-doped fuel cell electrolyte is low in energy consumption and low in preparation cost and has a relatively good economical advantage.

The invention provides a low-cost haze-removing auxiliary agent capable of rapidly eliminating haze and a preparation method. The preparation method comprises the following steps: enabling iron nitrate hydrate, ethylene glycol methyl ether and tetrabutyl titanate to react to prepare ferric oxide nano-crystalline hydrosol; meanwhile, enabling zinc acetate and lithium hydroxide to react in absoluteethyl alcohol, so as to prepare zinc oxide quantum dots; adding the zinc oxide quantum dots, water and glycerin into a homogenization machine together to prepare a dispersion body; adding the prepareddispersion body and liquid carbon dioxide into a dry ice particle manufacturing machine, and granulating to obtain the powdery low-cost haze-removing auxiliary agent capable of rapidly eliminating the haze. According to the method provided by the invention, a photocatalytic material is dispersed into the glycerin and the water, and can be completely dispersed in a utilization process, so that harmful gas sol in the haze can be rapidly and efficiently decomposed; a charge stable system of haze aerosol can be damaged; solid particles are stuck to form large particles, and then the large particles are rapidly deposited to the ground, so that the aim of rapidly eliminating the haze is realized; meanwhile, a preparation process is simple, and the production cost and the utilization cost are low; the low-cost haze-removing auxiliary agent has a good haze elimination effect and has an extremely wide application prospect.

The invention relates to a device preparation method for synchronously generating hydrogen energy and clean water by using light energy. A bamboo-like carbon nanotube-coated FeNi3 oxygen evolution electrocatalyst raw material is synthesized, and the method comprises the following steps: 1) adding ferric nitrate hydrate, nickel nitrate and urea into distilled water, and conducting stirring for 1 hour or more, wherein the molar ratio of iron to nickel is 1:2.5 to 1:3.5, and the amount of urea and distilled water is excessive; (2) soaking melamine sponge into the solution obtained in the step (1), and conducting aging in the air for 5 hours or more; and (3) conducting drying and carbonizing, grinding the obtained product into powder, and dropwise adding the powder on conductive glass sprayedwith the metal by a dropwise coating method to obtain an oxygen evolution electrode. Pt / C serves as a hydrogen evolution electrode, and maximum utilization from light energy to clean energy is achieved. Under the room temperature condition, the conversion efficiency from light energy to hydrogen energy is 20.1%, the efficiency of generating clean water through photo-thermal reaches 93.5%, and thecomprehensive utilization efficiency of solar energy reaches up to 87.5%.

The invention provides a preparation method of an Au-LaFeO3 nanocomposite material. The preparation method specifically comprises the following steps: carrying out a hydrothermal reaction on raw materials including lanthanum nitrate hydrate, ferric nitrate hydrate and citric acid, and calcining to obtain lanthanum ferrite nano-microspheres; and using L-lysine, HAuCl4 and trisodium citrate as raw materials to compound granular gold particles on the surface of the lanthanum ferrite nano-microspheres. The composite material of the invention shows high sensitivity and fast response and recovery toacetone, can be used in the field of acetone gas sensors to obtain novel gas sensitive materials with high sensitivity.

The invention provides a preparation method of composite hollow silicate, which relates to silicate. The invention provides the preparation method of the composite hollow silicate which has simpler process and is synthesized under the heat condition of a solvent. The preparation method comprises the following steps of: adding water and ethanol into MaSiO2, urea and nitrate hexahydrate and keeping constant temperature at the temperature of 170 to 190 DEG C for 4 to 36h, wherein the mixture ratio of the MaSiO2 to the urea is 1:(13.5 to 27) according to the mass ratio, the mixture ratio of magnesium nitrate hexahydrate to the urea is 1:(30 to 100) according to the mole ratio, and M is metal, metal oxide or metal oxide / metal; and after cooling a reaction product obtained in the step (1) to room temperature, washing the obtained solid product so as to obtain a target product of the composite hollow silicate.

The present invention describes a nucleating agent tailored specifically to the thermal energy storage medium lithium nitrate trihydrate (LiNO3-3H2O), and to the use thereof. Addition of the nucleating agent copper hydroxy nitrate hydrate [Cu3(OH)5(NO3)-2H2O](Likasite) suppresses the undercooling in lithium nitrate trihydrate, forming a superior composite thermal energy storage medium.

The application discloses a kind of bimetallic MOFs material of mesoporous structure and its efficient synthesis and screening method, with vanadyl sulfate and iron nitrate hydrate as two metal center ion source, with uniform benzene tricarboxylic acid as ligand material preparation formation mesoporous structure bimetallic MOFs material, 1,3,5-uniform benzene tricarboxylic acid is dissolved in mixed solvent one and obtained solution A, the mixed solvent one is 1:1 mixed solvent of ethanol and DMF;Metal salt one and metal salt two are dissolved in water, and a certain amount of ammonium fluoride is added, and gel B is formed;The metal salt one is Fe (NO3) 3·9H2O, and the metal salt two is VOSO4;Solution A is mixed with gel B and forms gel C after stirring for a certain time;Gel C is centrifuged and separated, then washed with ethanol, and then soaked in dichloromethane for multiple times;The obtained product is dried first, then activated, and powder D is obtained.The application can be synthesized at room temperature with bimetallic MOFs material with more optimal mesoporous structure, improve the yield, stability and excellent performance of material.

The invention relates to a petal-shaped manganese-cerium composite oxide denitration catalyst and a preparation method thereof, and belongs to the field of catalyst technology and environmental protection. The catalyst has a petal-shaped structure and is composed of a manganese-cerium composite oxide. The preparation method of the catalyst comprises the following steps: (1) dissolving potassium permanganate, manganous nitrate hydrate and cerous nitrate hydrate in deionized water, uniformly stirring and mixing, then adding into a hydrothermal reaction kettle, reacting for 10-15 hours at the temperature of 130-160 DEG C, and then cooling; (2) washing and centrifuging the turbid liquid obtained in the step (1), and then drying; and (3) roasting the product obtained in the step (2) in an air atmosphere to obtain the manganese-cerium composite oxide denitration catalyst. The manganese-cerium composite oxide denitration catalyst prepared by a hydrothermal method has abundant active sites and acidic sites, has a petal-shaped structure, and is beneficial to providing more active sites so as to promote gas adsorption.

The invention relates to a cerium-phosphorus complex flame retardant, a cerium-phosphorus complex flame-retardant polycarbonate composite material and a preparation method thereof, belonging to the technical field of polymer materials. The cerium-phosphorus complex flame retardant of the present invention comprises cerium nitrate hydrate and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO); the preparation method comprises: dissolving DOPO in In DMF, solution A is prepared, cerium nitrate hydrate is dissolved in deionized water to prepare solution B; solution B is added to solution A, and then hydrothermal reaction and dehydration treatment are performed. The cerium-phosphorus complex flame-retardant polycarbonate composite material of the present invention comprises 1-20wt% cerium-phosphorus complex and 80-99wt% polycarbonate; the preparation method comprises: separately cerium-phosphorus complex and polycarbonate Dry, premix and then melt blend. The flame retardant of the cerium-phosphorus complex of the invention has good dispersibility, can realize the flame retardant effect by utilizing the condensed phase mechanism and the gas phase mechanism at the same time, has a simple preparation method for the composite material, and has good flame retardant performance.

The preparation method comprises the following steps: respectively weighing cobalt-containing nitrate hydrate and 2-methylimidazole, adding the cobalt-containing nitrate hydrate and the 2-methylimidazole into methanol to prepare a solution, pouring the latter solution into the former solution, then adding a tungsten source, carrying out a stirring reaction at room temperature, and carrying out suction filtration, washing and drying so as to obtain the electrocatalytic bifunctional material. Centrifuging the obtained product, centrifugally washing the lower precipitate with methanol, drying at 50-70 DEG C, and calcining the obtained WS42-ZIF-67 at two stages of different temperatures in an inert atmosphere; and naturally cooling to obtain the electro-catalysis bifunctional material with few layers of WS2 nanosheets anchored on the surface of the cobalt-nitrogen-doped carbon-based polyhedron. The preparation process is simple and efficient, the requirement for equipment is low, and the prepared electro-catalytic bifunctional material is high in specific surface area, has a specific pore structure and excellent electro-catalytic performance, is used for electro-catalytic oxygen evolution and hydrogen evolution reactions and can replace noble metal catalysts such as Pt and RuO2.

The invention discloses a method for inducing superconducting-insulator phase change of two-dimensional Mo2C through doping of rare earth elements. The method comprises the following steps: 1, weighing Mo2C powder and nitrate hydrate containing the rare earth elements in a glove box protected by inert atmosphere; 2, putting Mo2C powder and nitrate hydrate containing rare earth elements into a polytetrafluoroethylene lining of a hydrothermal reaction kettle, and adding deionized water to form a mixed solution; 3, sealing and then carrying out hydrothermal reaction; and 4, separating the reaction product, and carrying out washing and vacuum drying to obtain the rare earth element doped Mo2C material. A hydrothermal synthesis method is adopted, rare earth elements uniformly enter Mo2C crystal lattices in an atomic scale through in-situ ion exchange and doping in the hydrothermal reaction process, the Mo2C material uniformly doped with the rare earth elements is prepared, phase change of the Mo2C material from a superconductor to an insulator is achieved, operation is easy, conditions are mild, and cost is low.

The invention discloses high-entropy rare earth zirconate superfine nano ceramic powder and a preparation method thereof, the molecular formula of the nano ceramic powder is (xREy) 2Zr2O7, RE is 5-6 of Eu, Gd, Dy, Ho, Sm, Y, Yb, Er, Nd and La, the value of x is 5 or 6, and the value range of y is 5%-35%; the preparation method comprises the following steps: dissolving ZrOCl2. 8H2O with the molar content percentage of 50% and 5-6 RE nitrate hydrate powder with the molar content percentage of 2.5%-17.5% in deionized water, then adding urea, stirring in a water bath, and carrying out suction filtration and washing while the solution is hot to obtain precursor powder; and then calcining and uniformly grinding to obtain the high-entropy rare earth zirconate superfine nano ceramic powder. The average particle size of the prepared high-entropy rare earth zirconate superfine nano ceramic powder is only 4-50 nm, the element distribution is uniform, the component adjustment space is large, and the high-entropy rare earth zirconate superfine nano ceramic powder does not contain impurities and the like. The preparation method has the advantages of low synthesis temperature, simple equipment, simple and controllable process, low industrialization cost and the like.

The invention relates to a method for preparing calcium ferroaluminates. The method comprises the following steps: proportionally mixing an aluminium nitrate hydrate, a calcium nitrate hydrate, a ferric nitrate hydrate, hexamethylenetetramine, acetylacetone, deionized water and the like uniformly by a sol-gel method, then stirring the mixture at the temperature of 50-70 DEG C to obtain sol, ageing the sol to form gel, carrying out heat treatment on the gel at the temperature of 750-800 DEG C for 2-4 hours and slowly cooling the gel to the room temperature, thus obtaining the calcium ferroaluminates. Compared with the prior art, the method has the following advantages: the preparation process is simple; the reaction process is easy to control; and the product has high uniformity and purity and can be fired at the temperature lower than the temperature in the traditional methods.

The invention discloses a high-thermal-conductivity hydrated nitrate composite phase change material, which comprises modified expanded graphite and a phase change material adsorbed around the modified expanded graphite, wherein the phase change material is hydrated nitrate or a hydrated nitrate-hydrated calcium chloride mixture, the mass content of the modified expanded graphite in the composite phase change material is 5-20 wt%, and the modified expanded graphite is hydrophilic modified expanded graphite of which the surface is attached with an aluminum oxide film. The invention also provides a preparation method of the high-thermal-conductivity hydrated nitrate composite phase change material. The method comprises the following steps: 1, modification of expanded graphite: soaking expanded graphite in a soluble aluminum salt solution, adjusting the pH value, filtering, and drying and calcining the solid; and 2, preparation of a composite phase change material: heating a phase change material, uniformly mixing the modified expanded graphite with the phase change material in a molten state, and cooling to obtain the high-thermal-conductivity hydrated nitrate composite phase change material.