129 results about "Lanthanum hydroxide" patented technology

A metal oxide catalyst capable of catalyzing an oxidative coupling of methane reaction is described. The metal oxide catalyst includes a lanthanum (La) cerium (Ce) metal oxide and further including a lanthanum hydroxide (La(OH)₃) crystalline phase. The catalyst is capable of catalyzing the production of C₂+ hydrocarbons from methane and oxygen. Methods and systems of using the metal oxide catalyst to produce C₂+ hydrocarbons from a reactant gas are also described.

The invention relates to a preparation method of an active carbon fiber phosphorous removing agent carrying lanthanum hydroxide. The invention belongs to the technical field of phosphorous removing agent preparation technology. The novel phosphorous removing agent provided by the invention has advantages of high phosphorous removing rate, high absorption rate, and the like. The phosphorous removing rate reaches above 99.5%. The method of the invention is characterized in that: a mixed suspension composed of a concentration of lanthanum nitrate solution and a concentration of sodium hydroxide solution is adopted; a certain amount of active carbon fiber is added to the mixed suspension; the mixture is stirred, filtered, washed, and a solid phosphorous removing agent is finally obtained. According to the phosphorous removing agent, a weight ratio of active carbon fiber to lanthanum hydroxide is 1:1 to 1:1.2.

The invention discloses an infusible metal material, belonging to compound nanometer material field. Especially relates to a method for using sol-gel method to produce nanometer compound rare earth molybdenum material. The method is, in ammonium molybdate solution, the lemon acid is poured in, and then the rare earth nitrate solution is added into the mixed solution. They are dried in the drying box, and form the dry gel. Then the dry gel is baked in furnace, forms compound of molybdenum trioxide and lanthana or lanthanum hydroxide. Finally, they are reduced for 1.5-2.5 hours under temperature of 400-450deg.C and 800-900deg.C in hydrogen furnace. The reduced compound rare earth lanthana is formed under pressure, and it is heated and baked into shape under high temperature and pressure in hydrogen furnace. The material particle is tiny, the density can reach to 95% of the ideal density, the rare earth oxide exists with nanometer particle, the emitting ability is strong, and it can be used as new negative material.

The invention relates to a complex alloy permeation agent and a method for preparing a permeation layer, designed aiming at the surface antisepsis of common steel spare parts, such as railway track fasteners, bolts, elastic bars, concrete preembedded parts, and the like. The complex alloy permeation agent comprises zinc powder, aluminum powder, alumina powder, lanthanum hydroxide powder and ammonium chloride. The process line for preparing the permeation layer comprises the following steps of: pretreating a working piece; loading the working piece into a furnace and adding the permeation agent; heating a converter and keeping the temperature for permeation; and cooling the working piece when reaching a temperature and discharging the working piece. Heat penetration is carried out under confirmed process specifications so as to form corrosion-resistant and wearable complex alloy permeation layer with a certain thickness and a compact structure on the surface of the working piece. The invention has simple process and is easy to implement. A Zn-Al-Fe-La complex alloy permeation layer obtained by adopting the conventional process has the thickness about 100 micros, the hardness up to 240-320 HV and the salt-air corrosion up to 680 h.

The invention provides a method for preparing platy lanthanum hydroxide nanocrystalline through a microwave-ultrasonic method. Analytically pure lanthanum nitrate hexahydrate and polyethylene glycol are added in deionized water to obtain a solution B; a potassium hydroxide or sodium hydroxide solution is added in the solution B to form a precursor solution C; the precursor solution C is poured into a four-neck round-bottom flask, the flask is put in a microwave-ultraviolet-ultrasonic trinity synthesis reaction apparatus, microwave heating and ultrasonic combination under a temperature-time mode is selected, the precursor solution C is cooled to the room temperature naturally after reaction is finished, a product is collected through centrifugation and then washed several times by deionized water and absolute ethyl alcohol, and the product is dried to obtain the final product platy lanthanum hydroxide nanocrystalline. The method adopts a simple microwave-ultrasonic preparation process, is short in reaction time period and low in energy consumption, reaction can be finished in liquid phase in one time, and no after-treatment is needed. La(OH)3 particles made by the method are of platy structures and are large in specific surface area, good in dispersibility and excellent in performance.

The invention belongs to the fields of wastewater treatment and high-molecular materials, and discloses a preparation method of gel for recovering phosphorus from water. The preparation method comprises the following steps: 1) dissolving polyvinyl alcohol in water completely to form a solution I, dissolving sodium alginate in deionized water completely to form a solution II, dissolving lanthanum hydroxide in water completely to form a solution III, and mixing the solution I, the solution II and the solution III to form a mixed liquor I; 2) adding the obtained mixed liquor I into mixed liquor II, performing a cross-linking reaction on the polyvinyl alcohol and the sodium alginate to form a polymer interpenetrating network structure, and embedding the lanthanum hydroxide in the polymer interpenetrating network structure to obtain gel; 3) flushing the obtained gel with deionized water repeatedly. In the preparation method, the lanthanum hydroxide is embedded into a copolymer of the polyvinyl alcohol and the sodium alginate by using the balling performance of the sodium alginate, the stability of the polyvinyl alcohol and the affinity of the lanthanum hydroxide to the phosphorus, so that an environment-friendly phosphorus recovering material is prepared.

The invention relates to a coating reinforcing agent. The coating reinforcing agent is characterized by comprising a liquid-state component A and a solid-state component B, wherein the coating reinforcing agent comprises 100 parts by weight of the component A and 35-40 parts by weight of the component B; and the liquid-state Component A is phosphoric acid, and the solid-state component B is lanthanum hydroxide or lanthanum oxide. The phosphoric acid-rare earth reinforcing agent is prepared through the reaction between the phosphoric acid and solid rare earth ( lanthanum hydroxide or lanthanum oxide), and after the rare earth reinforcing agent is added into an ordinary phosphate-metal aluminum powder coating, a phosphate in the reinforcing agent and a metal oxide in the phosphate-metal aluminum powder coating constitute a three-dimensional reticular structure based on hydrogen bond association, so that metal micro-powder is fixed in the three-dimensional reticular structure; therefore the binding ability of the coating is effectively improved, and the coating has better corrosion resistance.

The invention discloses nano-lanthanum hydroxide modified lignin porous carbon as well as a preparation method and application thereof. The preparation method comprises the following steps: preparingacetic acid lignin porous carbon: dissolving acetic acid lignin into a strong alkaline solution according to the ratio of 1 g to 5 mL, uniformly mixing and then drying to constant weight; carbonizinga dried solid mixture in an inert atmosphere, cooling to room temperature and then washing to neutral; carrying out vacuum drying to constant weight to obtain the acetic acid lignin porous carbon; preparing the nano-lanthanum hydroxide modified lignin porous carbon: adding the acetic acid lignin porous carbon into an ethanol aqueous solution of lanthanum chloride heptahydrate for uniformly mixing,adjusting a pH value of the solution, raising the temperature, fully reacting, sufficiently washing a reaction product and carrying out vacuum drying to constant weight to obtain the nano-lanthanum hydroxide modified lignin porous carbon. Highly-dispersed lanthanum hydroxide nanoparticles retain on the surface of the lanthanum hydroxide modified lignin porous carbon prepared by the preparation method disclosed by the invention; the absorption experiment shows that the modified acetic acid lignin porous carbon has a remarkable adsorbing effect on phosphorus, which is remarkably improved as compared with unmodified acetic acid lignin porous carbon.

The invention relates to a controllable preparation method of uniformly dispersed nano lanthanum oxide powder, belonging to the technical field of preparation of inorganic functional materials. In the preparation method, soluble trivalent lanthanum, sodium hydroxide, nitric acid and carbon black are used as raw materials, a black lanthanum hydroxide precursor is firstly prepared, and then temperature-programmed calcination is prepared to finally obtain the nano lanthanum oxide powder. The process has low cost, is easy to control and is convenient for industrial production, and the particle size of the prepared nano rare earth lanthanum oxide is within a range of 15nm-40nm; the nano rare earth lanthanum oxide has the advantages of small particle size, narrow range, good dispersibility, high purity and the like; in addition, the preparation method is superior to the traditional preparation method, because the traditional preparation method has the defects of expensive raw materials, high cost, complicated process, strict conditions and the like and is not suitable for large-scale and industrial production moreover, lanthanum oxide prepared by the traditional preparation method has the defects of large grain size and nonuniform distribution.

The invention relates to the technical field of a phosphorous removal adsorbent of expanded graphite loading lanthanum hydroxide and a preparation method of the phosphorous removal adsorbent. By taking expanded graphite as a matrix, the phosphorous removal adsorbent is loaded with hydroxide of a metal lanthanum, namely La(OH)3. The preparation method comprises the following steps: firstly preparing a 0.2-0.12mol/L lanthanum nitrate solution; preparing a lanthanum hydroxide precipitate; adding 0.2g of expanded graphite; oscillating for 20-120 minutes at constant temperature of 25 DEG C; after oscillation, centrifugalizing; taking out a solid in an upper layer; drying for 12 hours at 105 DEG C; and sealing for later use. The phosphorous removal adsorbent has a relatively high removal effect on phosphorous in water and the adsorption capacity can reach 16-20mg/g, and moreover, the phosphorous removal adsorbent further has the advantages of being easy to recover, stable to remove phosphorous, corrosion-resistant, heat-resistant, non-toxic and the like. The phosphorous removal adsorbent is simple in preparation process, low in energy consumption and short in time and has a broad application prospect.

The invention discloses a ceramic silicon carbide grinding wheel containing carbon reinforced fiber. The ceramic silicon carbide grinding wheel is prepared from following raw materials, by weight, 55 to 65 parts of silicon carbide, 30 to 35 parts of diamond abrasive, 10 to 13 parts of a short carbon fiber pre-dispersed material, 2 to 3 parts of a sintering additive, 4 to 5 parts of lanthanum hydroxide, 1 to 3 parts of potassium carbonate, 4 to 5 parts of kaolin powder, 2 to 3 parts of stearamide, 2 to 3 parts of epoxy resin, 1 to 2 parts of polyvinyl alcohol, and 80 to 90 parts of deionized water. The added short carbon fiber is capable of improving mechanical properties of silicon carbide, increasing breaking tenacity of ceramic, increasing strength and compactness of ceramic biscuit, and satisfying mechanical processing requirements; the added kaolin powder and epoxy resin are taken as binding agents, holding strength with the abrasive is increased, firm bonding is realized, hardness and grinding performance of the ceramic silicon carbide grinding wheel are improved, and service life is prolonged.

The invention discloses a preparation method for high dispersion nano lanthanum hydroxide. The preparation method comprises the following steps of dissolving lanthanum salt in water, organic solventsor mixtures of the water and the organic solvents to obtain lanthanum salt solutions; dissolving alkali in water, organic solvents or mixtures of the water and the organic solvents to obtain alkali liquor; adding the lanthanum salt solutions and the alkali liquor into a common reactor or a super-gravity rotating packed bed for precipitating crystallization reaction to obtain lanthanum hydroxide suspensions; placing the lanthanum hydroxide suspensions into a thermostat for aging treatment; adding the serous fluid after aging treatment to modifiers for modification; cooling the modified serous fluid to normal temperature, and ultra-filtering or centrifugally washing the serous fluid to obtain filter cakes; and dispersing the filter cakes into liquid media to obtain high dispersion nano lanthanum hydroxide liquid, or drying the filter cakes to obtain high dispersion nano lanthanum hydroxide powder. According to the method, the one-dimensional size of prepared lanthanum hydroxide particlesis 15-250 nm, and the particles are not agglomerated but dispersed for no less than 6 months.

The invention relates to a method that lanthanum hydroxide nano-particles with the even sizes are synthesized by utilizing of a coprecipitation method. The method comprises that a certain proportion (weight ratio) of a dispersing agent (the dispersing agent: lanthanum chloride=0.8:1) is stirred in a magnetic mode in lanthanum chloride dilute solution with certain density to enable the dispersing agent to be fully dissolved, the temperature is risen, and hartshorn with certain density is slowly dripped to react for 1-3 hours. White precipitate is obtained through centrifugal separation after cooling, ethanol and deionized water are used for washing the white precipitate respectively, and at last lanthanum hydroxide nano-particles are obtained through drying.

The invention discloses a preparation method of a nano-lanthanum hydroxide composite material, mainly comprising the following steps: putting macroporous ion exchange resin into a Tris-HCl buffer solution, reacting to obtain a macroporous polystyrene matrix material of which the surface is coated with polydopamine, filtering, putting into an La (III) salt solution, diffusing lanthanum salt to theouter surface of a sphere, and performing ammonium hydroxide in-situ precipitation to obtain the nano-lanthanum hydroxide composite material of which the loading amount is 5.9 to 35.2 percent. A method for removing trace phosphorus in waste water by using the composite material comprises the following steps: filling an adsorption column with the composite resin, then enabling trace phosphate infected water to directly flow through a filter column with an adsorbent from top to bottom, and when the concentration of phosphate in effluent is higher than 0.5mg/L, desorbing by using mixed liquor ofNaOH and NaCl and effectively regenerating. The treatment efficiency is high, the treatment capacity is great, the environmental protection benefit is obvious, and the content of the phosphate in theeffluent of the phosphate-infected waste water can be lowered to 50ppb or less.

The invention provides a composite corrosion inhibitor electrolyte, an application thereof and a magnesium air battery, and belongs to the field of air batteries. In the invention, La<3+> in lanthanumnitrate can react with OH<-> in the solution to generate lanthanum hydroxide to precipitate, and the structure and appearance of a passive film are changed, so that hydrogen evolution is inhibited, the damage effect of nitrate ions on the passive film is weak, and the integrity of the primary passive film is ensured, thereby having a good protection effect on internal battery materials, and inhibiting the hydrogen evolution. CTAB is a cationic surfactant, can significantly reduce the surface tension, change the surface state of metal/electrolyte, gather on the surface of active metal by utilizing the electrostatic adsorption of NH<2+>, reduce the surface energy of the metal and increase the corrosion activation energy, thereby slowing down the corrosion rate, and simultaneously forming alayer of hydrophobic protection film on the surface layer of the metal, thus hindering the charge and ion transfer, hindering the reaction process and reducing the corrosion rate.

The invention provides a carbon nitride/lanthanum hydroxide nanofiber membrane as well as a preparation method and application thereof. Nanofiber loading and lanthanum electron-deficient orbital characteristics are combined, an electrostatic spinning nanofiber membrane serves as a support to load carbon nitride, the agglomeration of the carbon nitride is prevented, the specific surface area thereof is increased, lanthanum hydroxide grows on a carbon nitride sheet layer in situ, and by means of the unique electron-deficient orbital structure of the lanthanum hydroxide, the separation of carbonnitride photo-induced electrons and holes is promoted, so that the photocatalytic activity is improved. In the prepared carbon nitride/lanthanum hydroxide nanofiber membrane, the carbon nitride and the lanthanum hydroxide are wrapped in nanofibers, and lanthanum hydroxide nanosheets grow on a carbon nitride sheet layer in situ. The prepared carbon nitride/lanthanum hydroxide nanofiber membrane canbe used for catalytically degrading dyes and catalytically producing hydrogen under visible light. The problems that carbon nitride is prone to agglomeration, aftertreatment is tedious, and the visible light utilization rate is low are solved.

The invention discloses a production technology of low-sulfur lanthanum hydroxide. The production technology comprises the following steps: (1) dissolving lanthanum carbonate in nitric acid to obtain a lanthanum nitrate solution; (2) regulating the pH value of the lanthanum nitrate solution obtained in the step (1) to 1.5-2, heating, adding the lanthanum carbonate to regulate the pH value to 4-4.5, and filtering to obtain filtrate; (3) concentrating and crystallizing the filtrate obtained in the step (2) to obtain a lanthanum carbonate crystal, and carrying out centrifugal dewatering; (4) dissolving the lanthanum carbonate crystal obtained by the centrifugal dewatering in the step (3), adding ammonium hydroxide to regulate the pH value to 7, standing to obtain a mixture which contains precipitates, and heating the mixture; (5) carrying out plate frame filtering on the heated mixture in the step (4) to obtain the precipitates; (6) drying the precipitates obtained in the step (5) on a vulcanization bed to obtain a low-sulfur lanthanum hydroxide finished product. In the lanthanum hydroxide product produced by the method, the sulfur content is less than 0.002%, and the contents of other metal impurities including calcium, iron, sodium, potassium, lead, manganese, magnesium, chromium, copper, zinc and the like are all less than 0.0005%.

The invention discloses a method for preparing lithium manganate by a wet-doping method. By the wet-doping method, manganese chloride solution, ammonium bicarbonate solution and lanthanum nitrate solution are reacted in aqueous solution. Lanthanum hydroxide and manganese carbonate are generated in a coprecipitation way. Manganic manganous oxide-doped crystals are obtained after high-temperature calcination, crushing and grading. Lithium carbonate and the manganic manganous oxide-doped crystals are mixed according to the molar ratio of lithium to manganese, and the molar ratio is 1.15:2. After being mixed effectively and uniformly, the above mixture is put into a kiln to be sintered at a high temperature. After cooling, crushing, grading, sieving and deironing of the sintered materials, spinel-shaped and lanthanum-doped lithium manganate is obtained. The method can combine materials and doping elements tightly. During the high-temperature calcination reaction, the doping elements can be inserted into crystal structures to be doped completely and fused with the doped crystals together. The doping of lanthanum element can raise the average oxidation state of manganese ions, inhibit Jahn-Teller effect effectively, reduce the capacity fading and raise the cycle performance.

The invention relates to a nanometer lanthanum hydroxide defluoridation adsorbent and a preparation method thereof. The preparation method comprises: 1, putting a reactor container in ice water at 10-35 DEG C and adding deionized water into the reactor container, 2, adding lanthanum nitrate solid powder into the deionized water in the step 1 and carrying out stirring dissolution through a stirrer,3, slowly adding a sodium hydroxide solution into the lanthanum nitrate solution and adjusting pH to 8.5-9.0, 4, repeatedly rinsing the solution in the step 3 through deionized water, 5, dehydratingthe washed slurry through a centrifuge and then drying the slurry, 6, grinding the dried slurry and screening dry powder of lanthanum hydroxide, and 7, mixing the dry powder of lanthanum hydroxide, microcrystalline cellulose and hydroxypropylmethylcellulose b and carrying out granulation through a wet granulator and a spheronizator. The preparation method is simple. The nanometer lanthanum hydroxide defluoridation adsorbent has high fluorine ion adsorbing efficiency and a long regeneration cycle.

The invention discloses a coupling agent-modified composite lithium iron phosphate positive electrode material. The material is characterized by being prepared from the following raw materials in parts by weight: 500 parts of lithium iron phosphate, 2 to 3 parts of silane coupling agent KH-550, 2 to 3 parts of calcium stearate, 1 to 2 parts of terpineol, 3 to 4 parts of lanthanum hydroxide, 4 to 5 parts of modified silver powder and a proper amount of water. According to the material, the modified silver powder is added, so that the electrical conductivity of the material is improved, the growth of crystals is effectively inhibited, and the obtained lithium iron phosphate material is uniformly dispersed; the bonding strength of carbon layers wrapping the surfaces of lithium iron phosphate particles is strengthened under the coupling effect of the coupling agent on an interface between an inorganic substance and an organic substance, so that the electrical conductivity and stability of the material are greatly improved; moreover, a process is simple, and the material is easy to industrially produce.

This invention relates to a method for preparing lanthanum hydroxide and lanthanum oxide nanotubes. The method comprises: (1) mixing 0.1-2 mol of water-soluble lanthanum salt and 1-20 mol of urea, and dissolving into water; (2) reacting at 50-120 deg.C for 0.1-168 h, cooling to room temperature, and filtering to obtain the precipitate; (3) washing with deionized water, and drying at 80-90 deg.C to obtain white powder of lanthanum hydroxide nanotubes; (4) calcining the lanthanum hydroxide nanotubes at 200-900 deg.C for 0.5-8 h, and cooling to room temperature to obtain lanthanum oxide nanotubes. The method has such advantages of simple process and high suitability for industrial production. The lanthanum hydroxide and lanthanum oxide nanotubes have potential applications in such fields as semiconductors, displays, high performance ceramics and catalysts.