315results about How to "Complete crystal form" patented technology

The invention discloses a preparation method of a lithium iron phosphate cathode material for a lithium ion battery, which comprises the steps of: placing a lithium source, an iron source, a phosphorus source and a doped source material into a stirring ball mill for mixing; adding the obtained mixture into a twin-screw extruder for reaction and extrusion; placing an extruded product into an inert atmosphere furnace, calcining for several hours at a temperature of 600-800 DEG C; and cooling in the furnace to obtain a sample, i.e. the lithium iron phosphate cathode material, wherein the lithium iron phosphate cathode material has high specific capacity (more than 140mAh/g, 0.2C) and excellent circulating property. The invention has the advantages of simple process and low cost, and is suitable for massive production.

The invention aims at providing a method for preparing a graphene material based on chemical deposition. The method comprises the following steps of: (1) uniformly mixing a soluble salt of a graphite catalyst, a polymer and an organic solvent; (2) adding a substrate in a reactor, heating the reactor to 450-1000 DEG C under the protection of inert gas; (3) introducing the mixture obtained by the step (1) into the reactor under the protection of inert gas to be subjected to chemical deposition; and (4) cooling and taking out the substrate, and removing catalyst particles by ultrasonic processing and acid pickling, thus the graphene material is obtained. In the invention, an organic solvent and a soluble polymer are adopted as the carbon sources, and a floating catalyst is used for cracking the carbon sources under the protective gas atmosphere, thus a single-layer or multi-layer graphene material is grown on the substrate, the graphene material is prepared in batch by chemical deposition, and the graphene material prepared by the method has the advantages of complete crystal form, low oxygen content and less defects.

The invention provides a preparation method of lithium-nickel-cobalt-aluminum oxide for anode materials of lithium ion batteries. The method comprises: step 1, using a nickel-cobalt-aluminum precursor prepared through a coprecipitation method and doped with mixed ions as raw materials, putting the raw materials into a sealed hearth of a pressure furnace, continuously introducing oxygen until a fixed pressure value is formed, then heating to a pre-burning temperature and keeping warm for a period of time, and cooling to obtain an oxidized precursor; and step 2, adding measured lithium salt or lithium hydroxide into the oxidized precursor, ball milling and uniformly mixing; heating the uniformly mixed raw materials to a certain temperature and keeping warm for a period of time, and meanwhile continuously introducing oxygen to complete a sintering process, thereby obtaining the finish product. According to the invention, through a hyperbaric oxygen atmosphere, the oxygen are enabled to fully infiltrate into particles of the raw materials which has a certain accumulation thickness, thereby preventing situations that only surface materials are oxidized under a normal pressure, and ensuring a full conversion of Ni<2+> to Ni<3+> by a full pre-oxidation.

The invention relates to a method for preparing nano-zeolite metal-organic framework compounds by a microreactor, and belongs to the technical field of preparation of nano-particles, which is characterized by comprising the following steps of: constructing a microreactor by a porous film; respectively dissolving a metal precursor and an organic ligand in a solvent to prepare a metal precursor solution A and an organic ligand solution B; respectively arranging the metal precursor solution A and the organic ligand solution B at two sides of the film; by a pressure difference of the two sides of the film, uniformly pressing reactants at one side of the film into reactants at the other side of the film through the pores of the film, to generate nano-particles; and centrifuging, washing and drying to obtain the target product. The method for preparing the nano-zeolite metal-organic framework compounds by the microreactor is simple in operation, strong in controllability of particle structure, and is suitable for preparation and industrial production of various nano-zeolite metal-organic framework compounds.

The invention provides a preparation method for hexagonal sheet magnesium hydroxide, which includes the following steps: 1 roasting natural magnesite to obtain light-roasting magnesium oxide, 2 adding the light-roasting magnesium oxide to magnesium salt aqueous solution according to a certain proportion, 3 enabling the suspension prepared in step 2 to react for a certain period of time in constant-temperature water bath under the condition of mixing, 4 adding magnesium hydroxide seed crystal after a certain period of time of reaction in step 3, and standing the reaction product in the constant-temperature water bath, and 5 filtering, washing and drying the product of step 4 to obtain the hexagonal sheet magnesium hydroxide with regular shapes. The preparation method for the hexagonal sheet magnesium hydroxide has the advantages that raw materials can be easily obtained, a process is simple, a step of traditional hydration hydro-thermal treatment is removed, energy consumption is reduced, and the preparation method is suitable for industrial production and the like. Different sizes and thicknesses of hexagonal sheet magnesium hydroxide can be prepared by changing process conditions of magnesium salt type and concentration, hydration temperature and time, standing time and the like. The prepared magnesium hydroxide can serve as seed crystal to be recycled so that production cost is lowered.

The invention provides a micro-level fine particle diamond synthesis process. The micro-level fine particle diamond synthesis process comprises the steps of mixing graphite powder and Fe-based alloy catalyst powder according to the weight ratio of 8:(5-7), then carrying out isostatic pressing and vacuum process and then carrying out compression molding on the mixture in a four-column press machine, putting a core column into a diamond synthesis block, and putting the diamond synthesis block into a cubic press to carry out synthesis, wherein the practical synthesis pressure is 6.1-6.6GPa, the synthesis temperature is 1000-1100 DEG C, and the practical synthesis pressure and the synthesis temperature are finished respectively by utilizing a control pressure curve and a power curve. According to the micro-level fine particle diamond synthesis process disclosed by the invention, the synthesized micron-level fine particle diamonds have the characteristics of large nucleation amount, short growth time and the like, products conform to an artificial diamond national standard and have consistent crystal forms, smooth crystal surfaces, a few of impurities and high hot punching values, the particle granularity of 270/325 and 325/400 is a peak value, a single crystal ratio reaches to 70-80%, and the micro-level fine particle diamond synthesis process can effectively meet the field of high-grade grinding tools and the like with high requirements on particle granularity.

The invention discloses a method for recycling lithium cobalt oxide from a waste positive electrode of a lithium cobalt oxide battery. The method comprises the following steps of: (1) feeding the waste positive electrode of the lithium cobalt oxide battery into a 1-2mol/L hydrochloric acid lixivium in which citric acid is dissolved, and reacting for 4-6 hours at 60-80 DEG C; (2) filtering the lixivium in the step (1) so as to separate aluminum foil and solid grains; and (3) washing and drying the solid grains; and (4) adding a lithium source into the solid grains to adjust the mass ratio of Co/Li in the solid grains, uniformly mixing, calcining and cooling so as to obtain lithium cobalt oxide. The method adopts the mixed acid of citric acid and hydrochloric acid as the lixivium so as to effectively separate a positive electrode material and the aluminum foil, the process is simple, and no toxic or harmful gases are generated. The first discharge capacity of recovered lithium cobalt oxide can still be 140mAh/g, and the discharge capacity after 40 times of charge and discharge circulation is not less than 90%.

The invention discloses a method for regulating and controlling preparation of nano calcium carbonate by using a crystal form control agent. By using cheap and accessible limestone as a calcium sourceand low temperature as a carbonization condition, the nucleation rate is controlled by the crystal form control agent by lowering the carbonization temperature of slaked lime to obtain nano calcium carbonate powder with finer particles; the obtained product is nano calcium carbonate powder with different morphologies, the average particle size is 20-100 nm, the crystal form is complete, the particle size is uniform, the dispersity is good, and the high additional value is achieved in the industries of rubber, paint, paint, printing ink and the like.

The invention discloses a method for preparing a magnetic P-type molecular sieve by using coal gangue. The method comprises: 1, grinding coal gangue, and carrying out high temperature calcining activating on the grinded coal gangue by using sodium carbonate; 2, oxidizing at a low temperature, adding hydrochloric acid, soaking, and filtering; 3, preparing an iron-doped molecular sieve from the filtration residue and the filtrate obtained after the filtration; and 4, placing the iron-doped molecular sieve in a porcelain boat, placing the porcelain boat in a tubular furnace, introducing nitrogen into the tube furnace, introducing hydrogen after the air in the tubular furnace is completely discharged, heating to a temperature of 650-700 DEG C, continuously carrying out a reduction reaction for 2-3 h, introducing nitrogen after completing the reaction, and cooling to a room temperature to obtain the magnetic P-type molecular sieve. According to the present invention, the coal gangue is used as the raw material, the Fe<3+> dissolution is performed with hydrochloric acid and is complexed by adding oxalic acid, and finally high temperature reduction is performed to prepare the magnetic P-type molecular sieve; the magnetic P-type molecular sieve has characteristics of high specific surface area and strong adsorption performance; and the magnetic P-type molecular sieve is easy to separate and recover through the external magnetic field, and the problem of high cost of the molecular sieve synthesis is solved.

The invention discloses a method for preparing phosphogypsum whiskers by secondary crystallization. The method comprises the steps of weighing dried phosphogypsum, adding a sulfuric acid solution, performing stirring reaction in a water bath, filtering when being hot, abandoning insoluble substances, cooling filtrate at room temperature for crystallization, performing suction filtration, and then retaining a filter cake; adding the sulfuric acid solution and a crystallization promoting agent, namely magnesium salt, performing stirring reaction in the water bath, naturally cooling the solution in the water bath for crystallization, performing suction filtration to obtain the whiskers, washing till neutrality and drying. The crystallization promoting agent is not used in primary crystallization in the method disclosed by the invention, the solid-liquid ratio of raw materials has a good effect, the reaction temperature and the stirring rotational speed are reasonably designed, the secondary crystallization method is created, the problems of short length-diameter ratio, low yield, difficulty in production under non-high pressure conditions and difficulty in succeeding without pretreatment of the phosphogypsum whiskers in the prior art are solved, the problems of phosphorus residue and the like can be solved by recycling a solvent, and the sustained cyclic production can be further realized. The length-diameter ratio of the whiskers produced by the method disclosed by the invention is more than 100, the whiteness is not less than 95%, and the product yield is improved by 10%-15%.

The invention provides a process method for preparing graphene by peeling off graphite. The method comprises the following steps: putting the graphite, a grinding material and concentrated sulfuric acid into grinding equipment, and grinding the materials to obtain a mixture; and separating the sulfuric acid and the grinding material out of the mixture, and washing and drying the remaining materials to obtain the graphene. The preparation flow of the graphene is very short, the cost is low, and the prepared graphene is complete in crystal form, has high conductivity, ad can be widely applied to a plurality of fields of battery materials, composite materials, electronic devices, energy storing materials and the like.

The invention discloses a sol-gel-hydrothermal method for preparing bismuth tungstate and indium-doped bismuth tungstate. The technical scheme point of the invention is to respectively disclose a sol-gel-hydrothermal method for preparing a bismuth tungstate catalyst and a sol-gel-hydrothermal method for preparing an indium-doped bismuth tungstate catalyst. The preparation method disclosed by the invention has the advantages of simple operation and low cost; and the prepared bismuth tungstate catalyst and the indium-doped bismuth tungstate catalyst have excellent photocatalysis performance.

This invention discloses a preparation method of hydroxylated cobalt and its application in water treatment. It relates to a preparation method of mixture and its application in water treatment. It is first time to disclose a preparation method of hydroxylated cobalt and its application in water treatment. Prepare hydroxylated cobalt: 1. add alkaline solution into divalence cobalt salt solution until no sediment emerging; 2. adjust suspension PH more than 12, activate; 3. filter, wash sediment to neutrality with distilled water, dry, and get hydroxylated cobalt. Hydroxylated cobalt is used as ozone catalytic agent for water treatment technology. This hydroxylated cobalt is of integrated and uniform particle crystal form, and uniform grain size. This invention avoids impurity precipitating. Hydroxylated cobalt purity reaches more than 99%. Hydroxylated cobalt can promote ozone to transform into hydroxy group free radicle, increase production rate and quantity of free radicle that is in water body. Ability of ozone removing organic contaminant that is in water can be raised 35-42%.

The invention discloses a preparation method of a nano yttrium aluminum garnet fluorescent powder, comprising the following steps of: preparing raw materials such as aluminium nitrate, yttrium nitrate and nitrate of the rare earth elements into mother liquor of which the total cation concentration is 0.1-1.0mol/L according to the proportion of 5: (3-X): X, wherein X is 0-0.1, reacting the evenly-mixed mother liquor in a depositing way by the means that weak base alcohol water solution or ammonia is added into an ultra-gravity field, and controlling the pH value at 7.0-8.0 so as to obtain turbid liquid; performing aging, extraction filtering, and microwave drying on the turbid liquid so as to obtain a precursor body; and putting the precursor body in a microwave field, and calcinating the precursor body so as to obtain a yttrium aluminum garnet fluorescent powder which is good in dispersity and has the particle size of 20-100 nanometers. Compared with the prior art, the preparation method has the advantages that the product has the mean grain size of about 20-100 nanometers, and the product is narrow in particle size distribution, free of conglobation, good in dispersity, high in crystallization degree, and free of transient phase. Furthermore, the preparation method is simple in technology, and can be used for quickly producing the nano yttrium aluminum garnet fluorescent powder in batches.

The invention discloses a powder catalyst for synthesizing ultrafine granular diamond. The powder catalyst is mainly prepared from the following alloying components by weight percent: 20% to 25% of Fe, 3% to 5% of Co, 0.5% to 2% of Ce, 3% to 5% of Mn, 0.5% to 1% of SiC, 0.5% to 1% of Mo and the balance being Ni. By utilizing the technical scheme of the powder catalyst, the high-purity ultrafine-particle spherical or approximately spherical powder catalyst can be prepared, and the granularity of the obtained powder catalyst is 600 to 1000 meshes. When the powder catalyst is applied to synthesis of ultrafine diamond single crystal, single-crystal diamonds within 400 meshes can be produced.

The invention relates to a copper-based ternary hydrotalcite thin film and a preparation method thereof, wherein a copper-zinc-alumium composite oxide thin film material complete, even and compact in crystal form is synthesized on a copper substrate by an in-situ growth method, and the thin film is high in adhesion and not easy to fall off. The method for preparing the thin film provided in the invention comprises the following steps of: putting a copper sheet in the mixed solution of boehmite sol and zinc nitrate, and growing CuZnAl-LDHs hydrotalcite thin film in situ on the copper sheet by controlling the reaction conditions such as pH, reaction temperature and time. The copper source of the copper-based ternary hydrotalcite thin film comes from the surface of the substrate; and compared with a hydrotalcite thin film formed through simple deposition on the substrate, the prepared thin film is better in adhesion to the substrate. Besides, the material has good corrosion resistance and is capable of protecting copper.

The invention provides single-substrate fluorescent powder for an ultraviolet excitation white-light LED (Light-Emitting Diode) as well as preparation and application methods thereof. The chemical molecular formula of the fluorescent powder is Sr2-x-yAyCeO4:xB<3+>, wherein A is selected from one of Li, Na and Mg, B is selected from one of Eu, Pr, Cr and Sm, x is not less than 0 and not more than 0.02, and y is not less than 0 and not more than 0.02. The single-substrate fluorescent powder is prepared through a hydrothermal method and a posttreatment incineration method. In the invention, according to the characteristic that the substrate Sr2CeO4 can give out broad-peak blue and green lights under the excitation of ultraviolet light and can give out red light with the doping of ion B, the purpose of compounding the blue and green lights and the red light to white light by regulating the proportion of x and changing the intensity of the red light is achieved. The doped ion A is used as a charge extender in the whole structure. The single-substrate fluorescent powder has the characteristics of high luminous intensity, even granularity, good dispersity, simple components, good chemical stability and the like.

The invention relates to a high-temperature dechlorination agent, which consists of 0 to 42 wt percent of CaOH, 18 to 70 wt percent of CaO, 20 to 40 wt percent of hydrotalcite, 7 to 17 wt percent of clay and 0 to 7 wt percent of adhesive. Based on the high-temperature dechlorination agent, the invention further discloses a preparation method of the high-temperature dechlorination agent. The high-temperature dechlorination agent prepared by the preparation method can be applied to a coal gasification fuel cell (MCFC) system, a coal gasification combination circulation power generation (IGCC) system and catalytic reforming regeneration gas so as to remove the HCl; furthermore, the dechlorination agent has high chlorine content and good dechlorination effect.

The present invention discloses a preparation method for cubic precipitated calcium carbonate. The method comprises the following processes: transporting refined and aged lime cream into a carbonation bubbling reactor with stirring, injecting purified and cooled limekiln gas to carry out carbonation reaction, when pH of the reaction mixture drops to 7.0, stopping the carbonation reaction, and controlling specific surface area (BET) of the finished calcium carbonate between 20-35 m<2>/g. Adding accelerating curing agent, heating to performing curing, maintaining the temperature between 60-90 DEG C for 2-15 hours, adding a surface treating agent, stirring the materials for 60 minutes to obtain a slurry of calcium carbonate, and subjecting the slurry to pressure filtration for dewatering, drying and pulverizing to obtain the calcium carbonate product. Compared with traditional heating curing methods, the present method has a higher curing efficiency, and obtains large cubic precipitated calcium carbonate particles in short time; size control and pH value control are more effective and more stable; the processed are simple and feasible, the costs are low, and economic effectiveness is good.