39results about "Calcium aluminates" patented technology

The invention relates to a recycling method of chemical polishing waste liquid, which comprises the following steps: (1) carrying out first pH regulation treatment on the chemical polishing waste liquid containing phosphate radicals, sulfate radicals, aluminum ions and + 3 valent iron ions to obtain aluminum mud and aluminum-removed liquid; (2) sequentially carrying out second pH regulation treatment, third pH regulation treatment and dealumination treatment on the aluminum mud to obtain a hydrated calcium aluminate product; (3) the aluminum-removed liquid is subjected to phosphorus removal treatment, and first phosphorus mud and phosphorus-removed liquid are obtained; sequentially carrying out fourth pH regulation treatment and first evaporative crystallization treatment on the first phosphorus sludge to obtain a sodium phosphate product; and sequentially carrying out fifth pH regulation treatment and second evaporative crystallization treatment on the dephosphorized liquid to obtain a sodium sulfate product. According to the method disclosed by the invention, phosphorus, sulfur and aluminum in the chemical polishing waste liquid are completely separated by utilizing different solubility of different substances in the solution when the pH value is the same, and a sodium phosphate product, a sodium sulfate product and a hydrated calcium aluminate product are respectively obtained, so that complete recycling of elements in the chemical polishing waste liquid is realized, and no byproduct waste is produced.

The invention relates to a method for binding sulfates in a body of water comprising sulfates, a calcined mixture prepared by calcining a mixture comprising calcium oxide and calcium alumina and / or calcium aluminate and cooling it to bind sulfates in a body of water, and the use of at least one element comprising CaO and mayenite supergroup and / or of a powder mixture and / or calcined mixture comprising at least one calcium aluminosilicate and / or at least one calcium aluminosilicate and / or calcium silicate for binding sulfates in a body of water.

The application discloses a method for preparing calcium aluminate for water treatment agent from impurity-removed solid waste by improved Bayer process, and belongs to the technical field of industrial solid waste utilization and water treatment agent preparation. The method takes desiliconized slag and deironed slag generated by improved Bayer process as core raw materials, and prepares calcium aluminate through the steps of solid waste washing treatment, filtrate recycling recovery, precise proportioning, mixing, grinding, high-temperature calcination reaction, crushing and screening, product detection and packaging, etc. Fluxing agents can be flexibly added or a segmented cooling optimization process can be adopted. The application realizes high-value resource utilization of solid waste of improved Bayer process, solves the problems of high cost and solid waste pollution caused by the dependence of traditional calcium aluminate preparation on natural minerals, and has high product purity, low heavy metal content and stable performance. The process is simple and controllable, and is suitable for large-scale production, and has remarkable environmental and economic benefits, and has a good application prospect in the field of water treatment agent raw material production.

The utility model discloses a pyrogenic process and wet process combined harmless and resource treatment system for aluminum ash, which comprises an aluminum ash raw material manufacturing subsystem, a mixed raw material manufacturing subsystem and a calcium aluminate manufacturing subsystem, the aluminum ash raw material manufacturing subsystem crushes, grinds and treats primary aluminum ash and secondary aluminum ash to obtain aluminum ingots and aluminum ash raw materials; the mixed raw material manufacturing subsystem is used for denitrifying the obtained aluminum ash raw material through a wet processing system, and mixing and grinding the denitrified aluminum ash, limestone and bauxite according to a certain proportion to obtain a mixed raw material; and the calcium aluminate production subsystem is used for carrying out pyrogenic calcination on the obtained mixed raw material and cooling to obtain calcium aluminate, and treating the calcium aluminate to obtain the finished product calcium aluminate. Nitrogen in the aluminum ash is removed and calcium aluminate is generated in a mode of combining a pyrogenic process and a wet process, and the calcium aluminate can be used for producing high-alumina cement and can also be used for producing building fireproof materials; the hazardous waste aluminum ash is harmless and recycled, and waste is turned into wealth.

The invention discloses a resource utilization method for preparing calcium aluminate through aluminum ash denitrification aluminum extraction-calcium roasting, and belongs to the technical field of aluminum ash resource processing. The method comprises the following steps: carrying out dry grinding on raw material aluminum ash to realize monomer dissociation to micron size, sieving, carrying out wet grinding on the obtained aluminum ash fine powder in a water-containing medium for denitrification, and sieving to recover metal aluminum and obtain aluminum-rich slag slurry; the aluminum-rich slag slurry is subjected to solid-liquid separation and soluble salt leaching treatment, and purified aluminum-rich slag is obtained; and the purified aluminum-rich slag is subjected to high-temperature calcium roasting, and the calcium aluminate system steelmaking refining slag with 12CaO. 7Al2O3 as the main crystalline phase is obtained. According to the method, physical separation, wet chemical reaction and pyrogenic calcination are combined for cooperative treatment, harmful elements such as nitrogen and fluorine can be efficiently removed, the aluminum ash of metal aluminum in the aluminum ash can be recycled, and harmless treatment, zero waste and all-component high-value utilization of the aluminum ash are achieved.

The invention provides a method for producing calcium aluminate powder by replacing part of bauxite with aluminum ash. The method comprises the following steps: respectively discharging secondary aluminum ash, limestone and bauxite from a raw material bin according to a ratio, and feeding into a stirrer; the preparation method comprises the following steps: uniformly stirring raw materials in a stirrer to obtain a mixture, spraying a liquid binder while stirring, and feeding the mixture into a high-pressure roller mill for treatment to obtain a material cake; feeding the material cake into a vertical mill through a discharging chute for grinding, separating fine powder through a powder concentrator under the driving of airflow, collecting the fine powder through a dust collector to obtain a raw material, and feeding the raw material into a homogenizing silo for storage; and feeding the raw material in the homogenizing silo into a preheater for preheating, feeding into a rotary kiln for calcining to obtain clinker, cooling the clinker, and grinding into powder to obtain the calcium aluminate powder. According to the invention, the homogeneity problem of the raw materials is effectively solved, the operation efficiency and stability of the system are improved, high-value utilization of multiple solid wastes is realized, the production operation environment is improved, the equipment corrosion risk is reduced, and the process adaptability is strong.

To provide a method for efficiently regenerating wastewater solutions of sodium hydroxide. [Solution] A method for regenerating a waste sodium hydroxide aqueous solution containing aluminum, comprising the steps of: mixing and reacting an aqueous slurry containing a calcium compound with the waste sodium hydroxide aqueous solution to form a reaction solution containing a supernatant liquid and a solid reaction residue; and subjecting the reaction solution to a solid-liquid separation treatment to remove the reaction residue, thereby recovering the supernatant liquid as a regenerated sodium hydroxide aqueous solution.

A molded sintered body containing a mayenite type compound, an inorganic binder sintered material, and a transition metal, wherein a content of the inorganic binder sintered material is 3 to 30 parts by mass with respect to 100 parts by mass of the molded sintered body, and the molded sintered body has at least one pore peak in each of a pore diameter range of 2.5 to 20 nm and a pore diameter range of 20 to 350 nm. A method for producing the molded sintered body, including mixing a precursor of a mayenite type compound and a raw material of an inorganic binder sintered material to prepare a mixture; molding the mixture to prepare a molded body of the mixture; firing the molded body to prepare a fired product; and supporting a transition metal on the fired product to produce a molded sintered body.

The invention relates to a method for preparing hydrocalumite to synergistically remove multicomponent impurities in rare earth feed liquid, and belongs to the technical field of separation, purification and high-value utilization of rare earth feed liquid. The method comprises the following steps: selecting air-cooled blast furnace slag, crushing, screening, uniformly mixing with NaOH particles, roasting, and air-cooling to room temperature to obtain an air-cooled mixture; leaching the air-cooled mixed material, stirring in distilled water, filtering, rinsing with distilled water, and drying to obtain the rare earth feed liquid impurity removal agent; the rare earth feed liquid is taken, the rare earth feed liquid impurity removal agent is placed in the rare earth feed liquid with the pH adjusted to be stirred, and the rare earth feed liquid with impurities removed is obtained. The method is mild in reaction condition, simple to operate and control, high in impurity removal efficiency, capable of well connecting upstream and downstream processes of rare earth smelting, excellent in process compatibility, high in universality for multi-component impurities in the rare earth feed liquid and capable of well covering removal of all-component impurities in the rare earth feed liquid.

An oxide ion-conducting solid electrolyte is provided. The oxide ion-conducting solid electrolyte contains a mayenite-type compound having a representative composition represented by Ca12Al14O33, and at least one metal element M selected from lanthanum (La) and yttrium (Y), wherein the metal element M is contained in a range of from 0.4 mol% through 5.3 mol% in terms of an oxide relative to the whole of the oxide ion-conducting solid electrolyte.

The invention relates to a method for preparing calcium aluminate by using alkaline residues, which comprises the following steps: adding an induced settling agent into alkaline residue slurry to promote the growth of calcium carbonate crystal grains in the alkaline residue slurry and further promote the settling of calcium carbonate, aluminum calcium carbonate and other products so as to facilitate subsequent better solid-liquid separation; carrying out dealkalization type liquid-solid separation treatment on the sedimentation liquid to obtain low-sodium modified alkaline residues and catalytic filtrate; reacting the catalytic filtrate with aluminum ash to obtain sodium aluminate, ammonia gas, methane and hydrogen; then carrying out solid-liquid separation to obtain modified aluminum ash with less leached fluorine and less volatile ammonia; and preheating and calcining the modified alkaline residues and the modified aluminum ash to obtain a target calcium aluminate product. The preparation method provides a thought for preparing high-quality calcium aluminate from the alkali residues discharged in the Bayer process aluminum oxide production process.

This invention belongs to the field of ceramic materials technology, specifically relating to ceramic fuse shells and their preparation method. The preparation method includes: ball milling a mixture of calcined α-alumina, borosilicate glass frit, γ-alumina, a composite grain bridging agent, a composite pore-sealing reinforcing agent, and deionized water; adjusting the pH to a neutral range; adding an aqueous solution containing polyvinyl alcohol and continuing mixing; sieving and spray drying to obtain granules; mixing with magnesium stearate and pressing into green bodies; placing the green bodies in a degreasing furnace; heating to different temperatures in stages under an air atmosphere and holding at those temperatures to complete degreasing; transferring the degreased green bodies to a sintering furnace; heating to a high temperature and holding at that temperature under a nitrogen protective atmosphere; and cooling in the furnace to obtain the finished ceramic shell. This invention, by introducing a composite grain bridging agent and a composite pore-sealing reinforcing agent, combined with staged degreasing and nitrogen atmosphere sintering, effectively improves the density, insulation performance, and bending strength of the shell, making it suitable for fuse applications.

The invention belongs to the technical field of asbestos tailing utilization, and particularly discloses an asbestos tailing full-resource utilization process. The method provided by the invention comprises the following steps: crushing and sieving asbestos tailings, adding a sulfating roasting reagent and ammonium bisulfate to obtain a mixed material, and roasting the mixed material in a fluidized bed; after heat preservation treatment, water is added for a leaching reaction, and leaching residues and filtrate are obtained through solid-liquid separation; adjusting the pH value of the filtrate to obtain a mixed precipitate of ferric hydroxide and nickel hydroxide and a sulfate solution, performing evaporative crystallization on the sulfate solution, and performing roasting treatment to obtain a mixed oxide; and adding aluminum powder into the mixed oxide, and carrying out aluminothermic reduction reaction to obtain the magnesium ingot. According to the method, high-valued utilization of various elements in the asbestos tailings can be achieved, circular economy and closed-loop utilization can also be achieved, and the economic effect of enterprises is improved.

An oxide ion–conducting solid electrolyte comprising: a mayenite compound having a typical composition represented by Ca12Al14O33; and a crystal phase of cerium oxide (CeO2).

The application belongs to the technical field of metal recycling and utilization, and provides an aluminum ash resource utilization method, in which metallic aluminum in aluminum ash is separated out first, and the remaining pretreated aluminum ash with low metallic aluminum content is washed with water, and then gamma type aluminum oxide and aluminum nitride in the aluminum ash are dissolved with sulfuric acid to obtain aluminum ammonium sulfate, aluminum sulfate solution and sulfuric acid insoluble alpha type aluminum oxide, the sulfuric acid insoluble alpha type aluminum oxide is mixed with calcium carbonate, and then high-temperature calcination and melting reaction are carried out to produce calcium aluminate, the calcium aluminate can be used as an aluminum source for subsequent production of polyaluminum chloride, the method of the application does not produce nitrogen gas, reduces the generation of hydrogen, has small danger and small pollution, eliminates the influence of fluoride, improves the resource utilization value of aluminum ash, and the recovery rate of metallic aluminum can reach 89.2%.

This utility model discloses a production line for producing calcium aluminate using aluminum ash, comprising a mixer, a first ball mill, a brick press, a tunnel kiln, and a conveying mechanism. The mixer is used to mix high-alumina alumina and calcium carbonate; the first ball mill is used to grind the mixture after mixing into a mixed powder; the brick press is used to press the mixed powder ground by the first ball mill into brick blanks; the tunnel kiln is used to calcine the brick blanks and includes a drying kiln chamber, a pre-firing kiln chamber, a calcining kiln chamber, and a cooling kiln chamber arranged sequentially; the conveying mechanism includes a material carrier and a drive assembly. The material carrier is used to carry the brick blanks, and the drive assembly is used to drive the material carrier sequentially through the drying kiln chamber, the pre-firing kiln chamber, the calcining kiln chamber, and the cooling kiln chamber. This utility model's production line for producing calcium aluminate using aluminum ash can reduce the impurity content of calcium aluminate, meet the requirements for the use of calcium aluminate in the water purification agent industry, and is conducive to its widespread application in the water purification agent industry, thus expanding the application range of aluminum ash.

This invention relates to the field of solid waste treatment and comprehensive resource utilization in the aluminum alloy processing industry, and discloses a method for the resource utilization of high-speed iron aluminum ash, comprising the following steps: (I) a coarse crushing, ball milling and screening stage, in which the high-speed iron aluminum ash is coarsely crushed, ball milled and then screened to obtain secondary aluminum ash, coarse material and fine material; (II) a magnetic separation stage, in which the coarse material and fine material are magnetically separated to obtain aluminum-containing material and iron-containing material; (III) a mixed smelting stage, in which the secondary aluminum ash, iron-containing material and quicklime are mixed to obtain a mixture, and the mixture is smelted to obtain calcium aluminate melt and molten iron. This solution effectively improves the resource utilization rate of high-speed iron aluminum ash by smelting the mixture of secondary aluminum ash, iron-containing material and quicklime in a furnace to recover iron resources in the form of molten iron; compared with the existing technology that treats iron-containing material and secondary aluminum ash separately, it not only effectively saves processing steps and shortens processing time, but also treats two kinds of hazardous waste (secondary aluminum ash and iron-containing material) simultaneously, and significantly reduces processing energy consumption and improves production efficiency.

The application discloses a harmless preparation method of calcium aluminate for water treatment from industrial aluminum ash, realizes harmless treatment of secondary aluminum ash, efficiently recovers aluminum in the aluminum ash, greatly improves purity of the calcium aluminate, reduces heavy metal ions, realizes effective treatment of the heavy metal ions, and has the following advantages: the calcium aluminate product obtained by the application has relatively simple phases, mainly Ca3Al2O6 and Ca12Al14O33 two phases with high calcium content; the method for preparing the calcium aluminate has low process cost, simple process, environmental protection and no pollution; the method can be widely applied to by-products generated in the aluminum industry; the method maximally improves aluminum utilization rate and effectively treats harmful elements such as heavy metals; and the final calcium aluminate product mainly contains Ca3Al2O6 and Ca 12 Al 14 O 33 two phases with high calcium content.

The present invention relates to a method for producing mayenite in the form of an electride, comprising: a) producing a feedstock suitable for obtaining, at the end of the following step c), a product containing more than 90% mayenite, comprising calcium and / or strontium, aluminum and oxygen atoms, as a mass percentage based on the mass of the crystalline phase; b) melting the feedstock until a molten material is obtained; and c) cooling the molten material to solidify it and obtain a polycrystalline molten product, wherein the melting is carried out using an electric arc furnace and in a reducing medium.

The present application relates to a kind of calcining control method for preparing calcium aluminate from aluminium ash, and the method comprises the following steps: judging the aluminum content index of secondary aluminium ash, classifying secondary aluminium ash according to the aluminum content index, obtaining raw material aluminium ash by matching different types of secondary aluminium ash, and controlling the aluminum content index of raw material aluminium ash.The method can solve the technical problems of normal operation affected by ring formation in the tail of rotary kiln and low firing rate of calcium aluminate caused by material caking when preparing calcium aluminate from aluminium ash.

The application discloses a method for microwave sintering and resource utilization of aluminum ash, which comprises the following steps: mixing aluminum ash with part of calcium-containing raw materials (including quicklime and limestone) to obtain a ball-mixed mixture; mixing the ball-mixed mixture with the remaining calcium-containing raw materials and microwave-assisted heating materials, and then uniformly mixing, briquetting and drying to obtain briquettes; sintering the briquettes in a microwave field; and cooling and crushing the sintered product to obtain a calcium aluminate product. The method can not only obtain a high-quality calcium aluminate product, but also effectively remove salts and harmful elements such as nitrogen in the aluminum ash; harmful element fluorine is solidified into calcium fluoride in the calcium aluminate product and serves as a useful component of a steelmaking desulfurizer. The method realizes harmless and resource utilization of the hazardous waste aluminum ash, and is simple in operation and friendly to the environment.

An oxide ion-conducting solid electrolyte includes a mayenite-type compound having a representative composition represented by Ca12Al14O33, wherein the oxide ion-conducting solid electrolyte contains 1.5 mol% to 7 mol% of barium (Ba) in terms of oxide.

The application provides a method and system for preparing high-purity SiC through self-adaptive collaborative conversion of fluctuating fly ash silicon-aluminum ratio, comprising: adopting a differential acid etching technology for silicon-aluminum separation; performing differential acid treatment on high-silicon and low-silicon fly ash to efficiently separate silicon-aluminum components in the fly ash in an acid activation-ultrasonic mechanical chemical coupling mode; adopting a deep deterministic policy gradient algorithm to construct a temperature decision model for precise temperature control; establishing a temperature decision model, and optimizing a temperature rising path and a holding time based on the deep deterministic policy gradient algorithm; in-situ resource utilization of excessive Al2O3 in a low-silicon phase to prepare high-performance SiC; and converting the excessive Al2O3 in the low-silicon phase into a functional carrier that can be used for preparing a composite material through an in-situ chemical reaction. The acid activation-mechanical chemical coupling method is used to dissociate silicon-aluminum in fly ash, a dynamic optimization carbon thermal reduction path mode is fused with a reinforcement learning algorithm, and the two modes are coupled to improve the quality and efficiency of SiC material prepared from fly ash.

The utility model discloses a material homogenizing device for calcium aluminate powder production, which comprises supports, the upper ends of the supports are fixedly connected with a homogenizing cylinder, the bottom of the homogenizing cylinder is provided with a discharge chute along the axial direction of the homogenizing cylinder, a bottom plate is fixedly connected between the supports, the bottom plate is provided with a discharge plugging device and is used for plugging the discharge chute, and the discharge plugging device is used for plugging the discharge chute. A hopper is fixedly connected to the top of the homogenizing cylinder, screening driving devices are arranged on the lower portion and the side wall of the hopper, and a homogenizing device is arranged in the homogenizing cylinder to rapidly homogenize powder. The utility model belongs to the technical field of material homogenization, and particularly relates to a material homogenization device for calcium aluminate powder production, which solves the problems of complicated working procedures, low material homogenization efficiency and long homogenization process time when raw materials of calcium aluminate powder are homogenized in the prior art.

The invention discloses a cerium-doped calcium hexaluminate photochromic material and a preparation method thereof, the chemical formula of the material is Ca (1-x) A112O19: xCe, and x is more than or equal to 0.0025 and less than or equal to 0.02; ce exists in a state that Ce < 3 + > and Ce < 4 + > coexist; the preparation method comprises the following steps: firstly, mixing Al (NO3) 3.9 H2O, CaCl2, Ce (NO3) 3.6 H2O, citric acid monohydrate and water, heating to obtain gel, and then carrying out heat treatment and calcination on the gel, thereby obtaining the catalyst. Before and after the material is irradiated by a 254nm portable ultraviolet lamp, a sample has obvious color change from white to yellow, the sample has an obvious absorption peak at 428nm, and the sample has a relatively large light reflectivity difference value before and after photochromism; and after the photochromic material is alternately subjected to ultraviolet irradiation and thermal stimulation for seven times, the photochromic performance is not obviously reduced, and the photochromic material has good reversibility.

An oxide ion-conducting solid electrolyte includes a mayenite-type compound having a representative composition represented by Ca12Al14O33 and a crystalline phase of cerium oxide (CeO2).

A system and method for continuous production of Mg from metallothermic reduction of magnesium bearing ore from both the reactor side and condenser side of the system, using a separate collection vessel. The furnace is a heated tube through which a moving bed of tableted feed flows. The condenser is a common heat exchanger design (shell / tube, plate / plate, etc.) and uses a heat transfer liquid to cool and condense magnesium gas under vacuum or pressure conditions. The cooling medium can be molten salts or metals which are not in direct contact with the magnesium metal. Liquid magnesium flows from the condenser into a collection vessel for further processing. Continuous operation is achieved by supplying a constant feed of tablets into the furnace, producing a constant stream of Mg gas to the condenser. Magnesium liquid product is tapped periodically from the collection vessel.

The invention discloses an efficient resourceful treatment method of firework and firecracker waste residues, which comprises the following steps: S1, sulfur dissolving separation: placing the firework and firecracker waste residues in a sulfur dissolving agent, and carrying out hot filtration separation to obtain a sulfur-containing clear liquid and desulfurized residues; cooling and separating out the sulfur-containing clear liquid, and carrying out solid-liquid separation to obtain sulfur and a sulfur dissolving liquid; s2, slurrying and leaching: adding the desulfurization residues into concentrated sulfuric acid to carry out slurrying reaction, dissolving magnesium and aluminum components, and carbonizing and decomposing lead fibers at the same time; s3, solid-liquid separation and flotation: diluting and cooling the material after the pulpifying reaction, and carrying out solid-liquid separation to obtain a leachate containing magnesium and aluminum ions and residues after leaching; and S4, magnesium aluminate spinel preparation: adjusting the pH value of the leachate to separate out magnesium and aluminum in a precipitation form, filtering, drying filter residues, and calcining to obtain the magnesium aluminate spinel. According to the method, sulfur, magnesium, aluminum and other resources in the waste residues can be safely and efficiently separated and recycled, meanwhile, the final residues are subjected to harmlessness, the amount and volume of the residues are greatly reduced, and the method is suitable for industrial-scale continuous production.

The embodiment of the invention provides a method for preparing a filter aid by activating lime milk, which comprises the following steps: carrying out first mixing on lime milk and Bayer process refined liquid to carry out pre-reaction to generate a primary filter aid; carrying out second mixing on the primary filter aid and crude liquid containing sodium aluminate to carry out deepening reaction, so that tricalcium aluminate crystals in the primary filter aid further grow in the crude liquid; carrying out solid-liquid separation on the liquid subjected to the second mixing to obtain a filter aid product; wherein the pre-reaction comprises the following parameters: the reaction temperature is 75-95 DEG C, the reaction time is 40 minutes to 3 hours, the reaction pressure is normal pressure, and the stirring speed is 50-150 revolutions per minute. Through the two stages of pre-reaction and deepening reaction, the generation and growth conditions of tricalcium aluminate crystals are optimized, and finally the technical problem of improving the filtering performance of the filter aid is effectively solved.