57 results about "Magnesium carbonate hydroxide" patented technology

The invention relates to a method for preparing basic magnesium carbonate from heavy magnesium water under the assistance of nano-micro bubbles, and belongs to the technical field of preparation of basic magnesium carbonate. According to the method, nano-microbubbles are generated and are stirred and mixed with heavy magnesium water, and energy released when the nano-microbubbles are broken is utilized to promote the decomposition reaction of the heavy magnesium water, so that efficient crystallization of basic magnesium carbonate is realized under a low-temperature condition. According to the technical scheme, the dependence of a traditional heavy magnesium water preparation process on high-temperature and vacuum conditions is broken through, the energy consumption and the production cost for preparing the basic magnesium carbonate are remarkably reduced, and a new path is opened up for preparing the basic magnesium carbonate from the heavy magnesium water.

The invention provides a carbon carrier for a catalyst, a preparation method of the carbon carrier, a fuel cell catalyst and a membrane electrode, and belongs to the technical field of fuel cells. The preparation method comprises the following steps: S1, uniformly mixing a carbon source, a nitrogen source, a phosphorus source and a template agent to obtain a mixture; wherein the template agent is selected from at least one of magnesium oxide, magnesium hydroxide, magnesium citrate, magnesium gluconate, magnesium acetate, basic magnesium carbonate, zinc oxide nanorods, titanium dioxide and mesoporous alumina; the mass ratio of the template agent to the carbon source is (0.1-15): 1; s2, calcining the mixture to obtain a calcined product; and S3, stirring the calcined product in an acid solution, filtering, washing and drying to obtain the carbon carrier. The carbon carrier obtained by the preparation method can have a relatively high mesopore ratio, an excellent graphitization degree and a proper heteroatom doping condition at the same time, and the electrochemical performance and durability of a fuel cell catalyst can be effectively improved.

The invention discloses a novel method for solidifying a foundation through cooperation of microorganisms and active magnesium oxide, and belongs to the technical field of foundation treatment. In a traditional foundation treatment method, a large amount of ore energy needs to be consumed in the production process of a reinforcing material, harm can be brought to the surrounding environment, and serious noise pollution, air pollution and the like are generated. According to the novel method for solidifying the foundation through cooperation of microorganisms and active magnesium oxide, the carbonation reaction between HCO3 <-> in a NaHCO3 solution and active MgO is accelerated through the catalytic acceleration effect of carbonic anhydrase on the CO2 hydration reaction, so that a large number of carbonates such as magnesium carbonate and basic magnesium carbonate with the good gelling effect are generated, solidified soil particles are cemented, and the effect of solidifying the foundation through cooperation of microorganisms and active magnesium oxide is achieved. And the effect of reinforcing the foundation is achieved.

The present invention discloses a method for preparing molten salt-modified magnesium oxide adsorbent particles for carbon dioxide capture. The method involves reacting magnesium chloride as a magnesium source with sodium bicarbonate to produce light basic magnesium carbonate, which is then calcined in stages to produce a microporous magnesium oxide precursor. The microporous magnesium oxide precursor is then impregnated with a mixed salt consisting of nitrate and carbonate, and dried to produce an alkali metal molten salt-modified magnesium oxide powder. A binder is added to the powder, and the powder is extruded to form a granular adsorbent. Applications of the adsorbent are also disclosed. The prepared adsorbent particles have good structural stability and are recyclable. When adsorbing and capturing CO2 at approximately 300°C, the loaded mixed salt forms a molten salt layer on the microporous surface of the magnesium oxide, enhancing CO2 adsorption. The CO2 adsorption capacity reaches over 10 mmol / g (adsorbent), which is more than 10 times higher than that of unmodified magnesium oxide adsorbent. The CO2 desorption rate is also significantly improved, reaching 100% at 400°C.

The invention relates to active magnesium oxide as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) reversely injecting a magnesium-containing solution into a carbonate solution to obtain a mixed solution; (2) reacting the mixed solution, and then performing dynamic gradient drying to obtain a basic magnesium carbonate precursor; the dynamic gradient drying comprises at least two drying stages; and (3) carrying out two-stage roasting on the basic magnesium carbonate precursor to obtain the active magnesium oxide. According to the preparation method of the active magnesium oxide provided by the invention, the reverse injection method, the solution reaction, the dynamic gradient drying and the two-stage roasting process are combined, and the crystallization kinetics and interface engineering in the preparation process are controlled, so that the prepared magnesium oxide has the characteristics of high activity, high specific surface area and high bulk density at the same time.

The utility model discloses basic magnesium carbonate purification and winnowing complete equipment which comprises a negative pressure conveying device, the negative pressure conveying device is connected with a buffer stock bin, the buffer stock bin is connected with an air flow sieve, the air flow sieve is connected with a cyclone separator, a lower outlet of the cyclone separator is connected with a finished product stock bin, and an upper outlet of the cyclone separator is connected with a bag-type dust collector. The bag-type dust collector is connected with an induced draft fan, and the negative pressure conveying device is connected with an air pump. Compared with the prior art, the device has the beneficial effects that impurities in magnesium carbonate material packages can be effectively removed, magnesium carbonate products with different stacking densities can be screened by setting parameters, the material loss is small, and the efficiency is high.

The invention discloses a method for oxidizing and separating manganese and magnesium and preparing basic magnesium carbonate by using manganese dioxide as a catalyst. The method comprises the following steps: firstly, adding a carbonization precipitator into a solution containing manganese and magnesium to preferentially precipitate and separate out manganese ions, and filtering to obtain manganese carbonate and filtrate A rich in magnesium ions; an oxidizing agent and a catalyst manganese dioxide are added into the filtrate A to catalyze oxygen residual divalent manganese ions and convert the divalent manganese ions into insoluble manganese dioxide, so that efficient separation of manganese and magnesium in the filtrate is realized, the manganese dioxide generated in the oxidation process forms self-enhanced circulation, catalytic activity is continuously provided, the oxidation efficiency is greatly improved, meanwhile, the dosage of the catalyst is reduced, and the cost is reduced. The oxidation reaction rate is stable; adding a carbonization precipitator and alkali into the treated filtrate, and carrying out staged reaction to enable magnesium ions to form high-purity basic magnesium carbonate precipitate. The process provided by the invention realizes efficient selective separation of manganese and magnesium, and the recovered product has high additional value, and can be widely applied to the fields of battery materials, catalysts, flame-retardant materials and the like.

The invention relates to a method for recovering a magnesium element from a magnesium-containing solution and application thereof, and relates to the technical field of wastewater treatment. According to the method, magnesium precipitation separation is achieved through the steps of alkalization, carbonization, flash decomposition and the like, and basic magnesium carbonate, active magnesium oxide and ammonium sulfate with high additional values can be recycled.

The invention discloses a method for mineralizing, reinforcing and protecting weathered sandstone cultural relics through carbon sequestration bacteria, and belongs to the technical field of cultural relic protection and restoration. In order to solve the problems of residue of deliquescent anionic salt and generation of bad byproduct ammonia gas in the existing technology for reinforcing and protecting sandstone cultural relics by microbial mineralization, the reinforcing depth and strength are improved in a lower-carbon and higher-efficiency manner, and an aspartic acid chelated calcium liquid containing low-solubility active magnesium oxide is effectively permeated into weathered sandstone; the carbon capture and nucleation effects of the bacillus mucilaginosus with the carbon sequestration function are utilized, on one hand, carbon dioxide in air is captured and converted into carbonate needed by mineralization, on the other hand, carbonate in an ammonium carbonate solution which is easy to volatilize and decompose is locked and used for carbonate mineral crystallization, and meanwhile ammonium ions are inhibited from being converted into ammonia gas to overflow; calcium carbonate and basic magnesium carbonate are induced to be subjected to intercrystallization nucleation, and a high-strength cementation structure is formed in pores of the weathered sandstone and is used for permeating, reinforcing and protecting the weathered sandstone cultural relics.

This invention belongs to the field of glass technology and relates to a high-temperature resistant structural glass material, its preparation method, and its applications. The glass is composed of the following components by mass percentage: 60%-70% silicon dioxide, 5.5%-11% boric acid, 0.1%-5% aluminum hydroxide, 0%-3% potassium nitrate, 5.5%-13% potassium carbonate, 0%-12% sodium carbonate, 0.1%-4% calcium carbonate, 0%-2% calcium fluoride, 0%-1% lithium carbonate, 0%-2% basic magnesium carbonate, 0.1%-1% titanium dioxide, 0%-2% zirconium dioxide, and 0%-1% cerium dioxide; the total mass percentage of potassium nitrate, potassium carbonate, sodium carbonate, and lithium carbonate does not exceed 22%. This structural glass possesses a high softening temperature, a suitable coefficient of thermal expansion, high-temperature resistance, thermal shock resistance, and processing performance, making it suitable as a structural material for optoelectronic devices.

The application relates to a method and device for pyrolyzing heavy magnesium water and basic magnesium carbonate, the method comprising: heating the heavy magnesium water; wherein a vacuum treatment is adopted, and the vacuum degree of the vacuum treatment is controlled to perform a first-stage pyrolysis of the heavy magnesium water; the vacuum treatment is stopped according to the first temperature of the heavy magnesium water to perform a second-stage pyrolysis of the heavy magnesium water, and basic magnesium carbonate is obtained. In the first-stage pyrolysis, it is also an induction period of pyrolysis. The heavy magnesium water is heated, and a certain vacuum degree is reached in the pyrolysis process by using the vacuum treatment, the carbon dioxide partial pressure in the pyrolysis is reduced, the induction period of the pyrolysis is controlled, the pyrolysis temperature in the first stage is reduced, the reaction rate of the pyrolysis is accelerated, and the energy consumption is reduced.

The invention discloses a method for preparing a low-oxygen magnesium fluoride optical coating material, comprising the following steps: (1) preparing a magnesium salt solution; putting metal magnesium into pure water, adding a nitric acid solution with a concentration of 3-5 times that of 20% for reaction, and adding hydrogen peroxide twice; (2) preparing an ammonium bicarbonate solution; (3) synthesizing basic magnesium carbonate; (4) cleaning the basic magnesium carbonate; (5) fluoridation; (6) heat preservation; (7) low-temperature drying and high-temperature dehydration to obtain high-purity magnesium fluoride. The invention has the following beneficial effects: step (1) adding hydrogen peroxide twice to remove impurities such as iron, manganese and heavy metals; step (4) cleaning the basic magnesium carbonate to determine the amount of impurities wrapped in the basic magnesium carbonate, determine the oxygen content of the magnesium fluoride, and prevent the generation of a pop point; step (6) heat preservation by layering to reduce the volatilization of hydrofluoric acid; all steps adopt commonly used industrial raw materials, and can prepare high-purity magnesium fluoride with a purity of more than 99.95%, meeting the requirements of purity, oxygen-free absorption and no pop point.

The invention discloses a method for preparing porous spherical basic magnesium carbonate based on bittern and application of the porous spherical basic magnesium carbonate in preparation of a flame-retardant synergist. Micron-sized porous spherical basic magnesium carbonate is prepared on the basis of bittern, and the nanoscale flame-retardant synergist is loaded through a simple self-assembly method, so that the problems that the flame-retardant efficiency of basic magnesium carbonate is low and the dispersity of the nanoscale flame-retardant synergist is poor are solved. The prepared flame retardant is simple in reaction process, low in energy consumption, short in consumed time, economical and environmentally friendly, magnesium-containing bittern is subjected to resource utilization again, the dispersity of a nanoscale flame retardant synergist is improved, the problems that a traditional basic magnesium carbonate flame retardant is low in efficiency, and preparation of a hybrid flame retardant is not environmentally friendly are solved, and the flame retardant is suitable for industrial production. And the flame retardant can be widely applied to the fields of chemical engineering, buildings, traffic, machinery and the like.

The invention belongs to the technical field of adsorption material preparation and polluted water body remediation, and particularly relates to a basic magnesium carbonate nanofiber adsorbent as well as a preparation method and application thereof. Aiming at the problems of high preparation cost of the current norfloxacin adsorbent and low norfloxacin adsorption capacity of the norfloxacin adsorbent, magnesium carbonate trihydrate is used as a reactant to react under the regulation and control action of citric acid and is converted into the basic magnesium carbonate nanofiber adsorbent. The preparation method is simple and low in production cost, and the obtained basic magnesium carbonate nanofiber adsorbent has high adsorption capacity on norfloxacin.

The application discloses a preparation method of titanium-doped and high-hydrated magnesio-chromian spinel monocrystal under high temperature and high pressure, and the method comprises the following steps: preparing a cylindrical magnesio-chromian spinel sample by taking solid basic magnesium carbonate powder, solid basic chromium acetate crystal powder, liquid tetraisopropyl titanate, solid oxalic acid powder, solid brucite powder, solid chromium hydroxide powder and liquid dilute nitric acid as starting raw materials; preparing water source sheets by taking brucite powder and chromium hydroxide powder with a weight ratio of 4:1 as water sources; placing two water source sheets at two ends of the cylindrical magnesio-chromian spinel sample and putting them into a double-capsule structure sample bin together to carry out high temperature and high pressure reaction, so as to obtain titanium-doped and high-hydrated magnesio-chromian spinel monocrystal; and the method solves the blank of the preparation technology of the titanium-doped and high-hydrated magnesio-chromian spinel large-grain monocrystal under the current high temperature and high pressure conditions, and obtains experimental samples of the titanium-doped and high-hydrated magnesio-chromian spinel large-grain monocrystal.

The invention relates to the technical field of preparation of active magnesium oxide, in particular to a method for preparing active magnesium oxide by taking magnesium hydroxide as a precursor, which comprises the following steps: 1) preparation of light-burned magnesium powder: crushing the light-burned magnesium powder until the particle size is less than or equal to 100 meshes; 2) water milling treatment: adding the crushed caustic-burned magnesia powder into water, and carrying out water milling treatment to obtain magnesium hydroxide slurry; 3) separating and washing: filtering and separating the magnesium hydroxide slurry subjected to water milling to obtain a magnesium hydroxide solid; washing the magnesium hydroxide solid with deionized water to remove surface impurities; 4) drying treatment: drying the washed magnesium hydroxide solid to obtain dried magnesium hydroxide; 5) carbonization treatment: mixing the dried magnesium hydroxide with deionized water according to a solid-to-liquid ratio of 1: (9-11) to generate a magnesium bicarbonate solution; 6) pyrolysis and calcination treatment: carrying out pyrolysis reaction on the magnesium bicarbonate solution to obtain basic magnesium carbonate; and calcining the basic magnesium carbonate to obtain the active magnesium oxide.

The application belongs to the field of high polymer materials, and particularly discloses a modified basic magnesium carbonate and a PA12 composite material and a preparation method thereof.The preparation method of the modified basic magnesium carbonate comprises the following steps: adding sodium carbonate and magnesium chloride into a sodium hydroxide solution to perform a water bath reaction to obtain the basic magnesium carbonate; adding the basic magnesium carbonate and acrylic acid into deionized water to perform a water bath reaction to obtain acrylic acid modified basic magnesium carbonate; and adding the acrylic acid modified basic magnesium carbonate, glycidyl methacrylate and an initiator into an organic solvent aqueous solution to perform a water bath reaction to obtain the modified basic magnesium carbonate.The modified basic magnesium carbonate prepared by the application can decompose and absorb heat at high temperature, release water vapor and carbon dioxide and other non-combustible gases, dilute the oxygen concentration on the surface of the combustion object, and reduce the temperature of the combustion area, so as to play a role in flame retardation.In addition, the magnesium oxide produced by decomposition covers the surface of the material to form a protective layer, and further prevents the combustion.

The invention belongs to the technical field of mineral processing treatment, and particularly discloses porous magnesium oxide based on dolomite and a macro-quantity preparation method of the porous magnesium oxide. The method comprises the following steps: crushing dolomite ore, and carrying out solid-phase reaction on the crushed dolomite ore and ammonium dihydrogen phosphate to obtain a mixture containing MgNH4PO4 and calcium phosphate; then selectively dissolving out magnesium in the mixture by using an acetic acid solution to obtain magnesium-rich filtrate and calcium hydrophosphate filter residues; mixing the magnesium-rich filtrate with ammonium bicarbonate for reaction to obtain basic magnesium carbonate precipitate and an ammonia-containing solution; sequentially carrying out first heat treatment and second heat treatment on the basic magnesium carbonate precipitate to obtain the porous magnesium oxide. According to the method, the porous magnesium oxide is successfully prepared on a large scale by taking the dolomite with large reserves and low cost as a direct raw material; the porous magnesium oxide also has the advantages of hierarchical pore structure and large specific surface area.

This invention discloses a method for preparing basic magnesium carbonate from calcium carbide production purification ash, belonging to the field of solid waste resource utilization. The method mainly utilizes carbon dioxide from the lime kiln gas in calcium carbide production to pressurize and carbonize the purified ash, obtaining high-concentration heavy magnesium water. This heavy magnesium water is then catalytically degassed to obtain high-purity wet basic magnesium carbonate. Furthermore, the waste heat from the lime kiln gas in calcium carbide production is used to dry the wet basic magnesium carbonate, obtaining basic magnesium carbonate powder. This technical solution utilizes the lime kiln gas from calcium carbide production in a site-specific manner, effectively treating waste with waste, and avoiding the traditional chemical method of using chemical reagents to treat purified ash from calcium carbide production to obtain basic magnesium carbonate. Simultaneously, the catalytic degassed treatment technology significantly improves the preparation efficiency and recovery rate of basic magnesium carbonate, providing a new solution for calcium carbide production purification ash.

The present invention provides a wet treatment process for laterite nickel ore. The wet treatment process comprises step S1, high-pressure acid leaching of laterite nickel ore, solid-liquid separation and washing to obtain filtrate and filtrate residue; step S2, alkali washing the filtrate residue with alkali solution to obtain hematite; step S3, pressurized iron removal treatment of the filtrate and washing solution to obtain hematite product and iron removal liquid; step S4, neutralization and iron removal treatment of the iron removal liquid with a first neutralizer to obtain neutralized residue and neutralization and iron removal liquid; step S5, aluminum-chromium precipitation treatment of the neutralization and iron removal liquid with a second neutralizer to obtain aluminum-chromium residue and iron removal aluminum liquid; step S6, nickel-cobalt-manganese precipitation treatment of the iron removal aluminum liquid with a third neutralizer and an oxidant to obtain a crude nickel-cobalt-manganese hydroxide precipitate and a precipitated liquid; and step S7, magnesium recovery treatment of the precipitated liquid to obtain a basic magnesium carbonate product and tail liquid. The process has almost no waste residue discharge and has high economic benefits.

The present invention discloses a method for oxidatively separating manganese and magnesium by using manganese dioxide as a catalyst and preparing basic magnesium carbonate. First, a carbonization precipitant is added to the manganese-magnesium-containing solution to preferentially precipitate manganese ions, and manganese carbonate and filtrate A rich in magnesium ions are obtained by filtration; an oxidant and the catalyst manganese dioxide are added to filtrate A to catalytically oxidize the remaining divalent manganese ions and convert them into insoluble manganese dioxide, thereby realizing the efficient separation of manganese and magnesium in the filtrate. The manganese dioxide formed during the oxidation process forms a self-enhancing cycle, continuously providing catalytic activity, greatly improving the oxidation efficiency, reducing the catalyst dosage at the same time, and ensuring the stability of the oxidation reaction rate; a carbonization precipitant and an alkali are added to the treated filtrate, and through staged reactions, magnesium ions form high-purity basic magnesium carbonate precipitate. The process of the present invention realizes the efficient and selective separation of manganese and magnesium, and the recovered products have high added value and can be widely used in fields such as battery materials, catalysts, and flame retardant materials.

The utility model relates to the technical field of chemical product mother liquor treatment, and discloses a sodium carbonate mother liquor purification device which comprises a mixing tank, a stirring unit, a concentration and separation unit and a washing unit, a quantitative box is fixedly connected to the top end of the mixing tank, a feeding port is fixedly connected to the top end of the quantitative box, a discharging port is formed in the front portion of the bottom end of the quantitative box, an electric push rod is fixedly connected to the rear portion of the bottom end of the quantitative box, and a movable plate is fixedly connected to the telescopic end of the electric push rod. The middle of the front end of the movable plate is fixedly connected with one end of a push column. According to the utility model, sodium carbonate mother liquor and quantitative magnesium chloride are subjected to mixed reaction, heating concentration and solid-liquid separation are carried out, solid is separated, impurities are washed to obtain a basic magnesium carbonate product, and separated liquid is continuously concentrated and separated, so that the sodium carbonate mother liquor is recycled, excessive residual saturated solution is not generated during the period, and the generation of new mother liquor is avoided; and the utilization efficiency of resources is improved.

The invention discloses an Mg3TiO5 microwave dielectric material and a preparation method thereof, and belongs to the field of microwave dielectric materials, the chemical formula of the microwave dielectric material is Mg3TiO5, the Q * f of the microwave dielectric material is 198000GHz, and the fluctuation of the microwave dielectric property within the range of-50 DEG C to 200 DEG C is less than or equal to 5%; the preparation method comprises the following steps: (1) proportioning MgO or basic magnesium carbonate with the purity of more than 99% and the particle size of 400-600nm and TiO2 according to product element composition to obtain initial powder; (2) carrying out ball milling, drying, sieving and presintering on the initial powder obtained in the step (1), and then carrying out secondary ball milling, drying and sieving; and (3) adding a polyvinyl alcohol solution into the powder obtained in the step (2) for granulation, then carrying out compression molding, and sintering the obtained green body in the air atmosphere of 1320-1440 DEG C to obtain the Mg3TiO5 microwave dielectric material.

This invention discloses a method for the comprehensive recycling of titanium-containing blast furnace slag leachate, comprising the following steps: S1, titanium-containing blast furnace slag is crushed, roasted, and acid-leached to obtain titanium-rich material and leachate; S2, the pH of the leachate is adjusted with ammonia to obtain aluminum hydroxide and filtrate 1; S3, filtrate 1 is reacted with an oxidant to obtain manganese dioxide and filtrate 2; S4, filtrate 2 is adjusted with sodium hydroxide, and then sodium carbonate is added to react to obtain calcium and magnesium precipitate and filtrate 3; S5, filtrate 3 is adjusted with nitric acid and then separated by a bipolar membrane to obtain sodium hydroxide and nitric acid; S6, the calcium and magnesium precipitate is stirred with water and then reacted with carbon dioxide to obtain filtrate 4 and light calcium carbonate; S7, filtrate 4 is decomposed by heating to obtain basic magnesium carbonate. This invention not only achieves high-value utilization of titanium, calcium, magnesium, aluminum, and other elements in titanium-containing blast furnace slag, but also recycles the nitric acid, sodium hydroxide, ammonia, and carbon dioxide used, resulting in low production costs and high added value of the prepared products.

The invention discloses medicinal light magnesium oxide and a preparation method thereof, and relates to the technical field of preparation of medicinal auxiliary materials. The preparation method comprises the following steps: S1, primarily calcining magnesite to prepare light calcined magnesia; s2, digesting light calcined magnesia to prepare magnesium hydroxide slurry; s3, carbonizing the magnesium hydroxide slurry to prepare a magnesium bicarbonate solution; s4, preparing basic magnesium carbonate through pyrolysis and concentration; and S5, preparing the light magnesium oxide by secondary calcination: carrying out secondary calcination on the basic magnesium carbonate prepared in the previous step at 650-750 DEG C for 3-4 hours to obtain a calcined product, namely the light magnesium oxide, and then crushing and packaging the light magnesium oxide. According to the preparation method, by accurately controlling the secondary calcination temperature and time of basic magnesium carbonate, especially by stepwise controlling the temperature rise speed and heat preservation time of the secondary calcination temperature, the generation rate and specific surface area of magnesium oxide grains in the product are controlled, so that the ethanol adsorption capacity of light magnesium oxide is greater than or equal to 1.8 g / g, and the light magnesium oxide has a good ethanol adsorption capacity. Further, the requirements of pharmaceutic adjuvants with high ethanol adsorption capacity can be met, and the product is high in purity and uniform in particle size distribution.

The invention discloses a preparation method and application of a tough composite filter aid, and relates to the technical field of filter aid preparation, the preparation method comprises the following steps: S01, rice hull crushing, S02, rice hull powder sorting, S03, wood powder crushing, S04, wood powder sorting, S05, basic magnesium carbonate selection, S06, anti-mildew agent selection, and S07, composite powder preparation, poplar wood with low cost is adopted as a raw material, the production cost is effectively reduced, and the production efficiency is improved. Through a fine crushing and sorting process, the rice hull powder and the wood flour show higher toughness, the anti-cracking performance of a filter cake is remarkably improved, the continuity and the stability of the filtering process are ensured, porous petal-spherical tetrahydrate basic magnesium carbonate is selected as an active component, the filtering efficiency is remarkably improved through the porous characteristic of the porous petal-spherical tetrahydrate basic magnesium carbonate, and the service life of the filter cake is prolonged. And the method plays an important role in enhancing the toughness of the filter cake.

The application belongs to the technical field of carbon dioxide adsorbents, and provides a magnesium oxide-based carbon dioxide adsorbent and a preparation method thereof. Basic magnesium carbonate is calcined to obtain magnesium oxide powder; the magnesium oxide powder is immersed in an alkali metal salt solution and then dried to obtain magnesium oxide powder loaded with alkali metal; the magnesium oxide powder loaded with alkali metal is immersed in a calcium nitrate solution and then sequentially subjected to drying, calcination and refinement treatment to obtain the magnesium oxide-based carbon dioxide adsorbent. The adsorbent of the application effectively improves the carbon dioxide adsorption capacity and cycle stability of the adsorbent through the mutual synergistic effect of magnesium oxide, sodium ions, potassium ions, manganese ions and calcium oxide and by controlling the proportion of each component and the process parameters, has high carbon dioxide removal rate, and has excellent cycle regeneration performance; the immersion of magnesium oxide in the alkali metal salt solution can further increase the pores of the adsorbent, which is conducive to the diffusion of carbon dioxide in the interior of the adsorbent.

The invention belongs to the technical field of chemical material synthesis, and particularly relates to a method for preparing high-activity magnesium oxide by taking hydrated magnesium carbonate as a precursor, which comprises the following steps: adding ammonia water into an industrial salt solution, removing sodium nitrite, heating to 60-80 DEG C, adding a sodium hydroxide solution, precipitating and filtering generated magnesium hydroxide, washing with deionized water for multiple times, and drying to obtain magnesium oxide. Residual chloride ions and sodium ions are removed; mixing the washed magnesium hydroxide with hydrated basic magnesium carbonate, drying, removing surface moisture and crystal water from the hydrated basic magnesium carbonate, and calcining the dried product; and crushing and screening to obtain a magnesium oxide finished product. The hydrated basic magnesium carbonate and the magnesium hydroxide are mixed and then calcined, the calcination temperature is reduced, the decomposition temperature of the magnesium hydroxide is lower than that of the hydrated basic magnesium carbonate, and the overall pyrolysis energy consumption can be reduced after mixing. The synergistic effect is that active MgO and H2O are generated through decomposition, and decomposition kinetics of hydrated basic magnesium carbonate can be promoted.

The invention discloses a preparation method and application of a composite filter aid for food, and relates to the technical field of filter aids. The preparation method comprises the following steps: S1, crushing the peeled puffed corn, S2, sorting the peeled puffed corn flour, S3, crushing the peeled puffed rice, S4, sorting the puffed rice flour, S5, selecting the porous petal spherical tetrahydrate magnesium carbonate, S6, selecting the food-grade carclazyte and S7, mixing and preparing. According to the preparation method, the composite filter aid for the food is prepared through effective blending and compounding in the process steps S1-S7, after compounding, the composite filter aid is stacked with large and small particle sizes, the pore size among particles is effectively adjusted, and various materials are of porous structures, are different in pore size and are compounded together, so that the blocking and adsorption effects on particles with different sizes in oil residues are achieved; large residues are blocked in pores among particles, and small residues are adsorbed in the pores, so that the defects that a filter screen is easy to leak fine particles, food-grade diatomite and carclazyte filter cakes are easy to crack and the like can be effectively overcome.

The invention relates to the technical field of magnesium carbonate preparation, in particular to a decomposition method and a decomposition system of a magnesium bicarbonate solution. The decomposition method comprises the following steps: carrying out first magnetization on a magnesium bicarbonate solution in a flowing state by using a fixed magnetic field to obtain a magnetized magnesium bicarbonate solution; mixing a surfactant and the magnetized magnesium bicarbonate solution to obtain a mixed solution; carrying out secondary magnetization on the mixed solution by using an alternating magnetic field, then carrying out heat preservation on the mixed solution subjected to secondary magnetization, and carrying out low-temperature decomposition on the mixed solution subjected to secondary magnetization to obtain an emulsion; carrying out solid-liquid separation on the emulsion to obtain a filter cake; and drying the filter cake to obtain a basic magnesium carbonate product, wherein the magnetic field intensity of the fixed magnetic field is less than or equal to 1600mT, and the magnetic field amplitude of the alternating magnetic field is less than or equal to 800mT. According to the decomposition method, the surface tension of the magnetized magnesium bicarbonate solution is reduced in a two-stage magnetization mode in cooperation with the surfactant, and therefore the decomposition rate of the magnetized magnesium bicarbonate solution for decomposing basic magnesium carbonate can be increased to 95% or above.