3987 results about "Carbonic acid" patented technology

The invention discloses a method for preparing diester terephthalate by catalyzing polyethylene glycol terephthalate (PET) to depolymerize. The method comprises the following steps: treating PET or a composite system thereof in diester carbonate under the conditions of no catalyst or taking a salt substance as a catalyst to realize chemical depolymerization of PET, so as to obtain PET monomers of diester terephthalate and ethylene carbonate, and realize complete depolymerization of PET in a composite. According to the method disclosed by the invention, through the reaction of the diester carbonate and the PET, the depolymerization of the PET under a mild condition can be realized, and the related technology research and development of chemical recovery of the PET monomer in a PET composite system or a mixed system are further carried out. The method provided by the invention has the advantages of high efficiency, greenness, mild reaction conditions and the like, can catalyze PET depolymerization to generate the monomer terephthalic acid diester, and has higher industrial application value.

The present invention relates to the technical field of waste gas treatment, and discloses a low carbonic acid tower for tertiary carbonic acid production, the low carbonic acid tower comprises a tower body, the inner wall of the tower body is provided with a plurality of groups of support frames, the support frames are internally provided with filler layers, the lower parts of the support frames are provided with distribution plates, and trickling ports are uniformly distributed at the bottom of a spray pipe, so that the tertiary carbonic acid production efficiency is improved, and the tertiary carbonic acid production efficiency is improved. According to the waste gas absorption tower, through the arrangement of the filter layer, dripped absorption liquid can better cover the interior of the tower body, so that waste gas and the absorption liquid can be better in countercurrent contact, when the absorption liquid flows through the arranged filler layer, the contact area of the absorption liquid and the waste gas can be increased, and an adsorption sieve in the filler layer can also adsorb some harmful substances in the waste gas; and the distribution plate is arranged below the spraying pipe, so that the absorption liquid can be secondarily distributed and is uniformly distributed in the tower body again, and the condition of non-uniform distribution of liquid drops is avoided.

In order to solve the problem that an existing high-voltage lithium ion battery is insufficient in high-temperature performance and safety performance, the invention provides a cyclic carbonate-sulfate compound and application thereof, a non-aqueous electrolyte and a secondary battery, and the cyclic carbonate-sulfate compound comprises a compound as shown in a chemical formula 1, the specific rotation [alpha] of the cyclic carbonate-sulfate compound ranges from-7.982 degrees mL / (dmg) to + 7.982 degrees mL / (dmg), and the specific rotation [alpha] of the cyclic carbonate-sulfate compound ranges from-7.982 degrees mL / (dmg) to + 7.982 degrees mL / (dmg); the chemical formula 1 of the # imgabs0 # is shown in the specification. When the cyclic carbonate-sulfate compound provided by the invention is used as an electrolyte additive, a formed solid electrolyte membrane is smoother and more ordered, so that the cyclic carbonate-sulfate compound has higher high-temperature stability, especially membrane layer stability under a thermal shock condition.

A forest fire retardant composition contains a retardant compound that includes a potassium salt. The potassium salt may include a potassium salt of an organic acid, a potassium salt of an inorganic acid, or mixtures thereof. The organic acid may include formic acid, acetic acid, propanoic acid, butanoic acid, lactic acid, oxalic acid, malic acid, gluconic acid, tartaric acid, uric acid, malic acid, or citric acid. The inorganic acid may include sulfuric acid, phosphoric acid, carbonic acid, or hydrochloric acid. The composition may be in the form of a dry concentrate, a liquid concentrate, or a final diluted product. The final diluted product is effective in suppressing, retarding, and controlling forest fires while exhibiting corrosion resistance and low toxicity.

The invention discloses a method for removing lead and supplementing nickel from electrodeposited nickel anolyte, which relates to the technical field of nickel wet smelting, is used for purifying and removing lead from anolyte of a pure sulfuric acid system, and comprises the following steps of: adding the electrodeposited anolyte into refined nickel sulfate oil-removed liquid and nickel carbonate slurrying liquid, introducing air, controlling the temperature, and entering an acid dissolution lead removal tank for acid dissolution; and filtering the acid-dissolved solution through an acid dissolution filter press, pumping the obtained primary filtrate into a precision filter, pumping the obtained secondary filtrate into a secondary filtrate storage tank, pumping the secondary filtrate into a catholyte tank through a secondary filtrate delivery pump, and enabling the obtained catholyte as an electrodeposition cell catholyte to enter an electrodeposition process. The method has the advantages of being short in technological process, high in lead removal efficiency, simple and convenient to use, easy to filter, low in energy consumption, capable of recycling the falling solution, convenient for industrial production and the like.

The invention relates to the technical field of solid waste treatment, in particular to a flotation method and system for waste incineration fly ash decontamination and calcium conservation. The method comprises the steps that waste incineration fly ash is placed in a natural environment to be subjected to a natural carbonation reaction till the pH value is 7-9, pretreated fly ash is obtained and mixed with water, and then a collecting agent and a foaming agent are added for flotation separation; or mixing the waste fly ash by using the sulfuric acid aqueous solution as the flotation liquid, and then adding the collecting agent and the foaming agent for flotation separation; wherein the collecting agent is one or more of butyl xanthate, ammonium dibutyl dithiophosphate and N, N-diethyldithiocarbamate. By means of the method, heavy metal and chlorine salt in the fly ash can be removed, Ca-based components in the fly ash can be reserved, and therefore resource utilization of the waste incineration fly ash is achieved to the maximum extent.

Provided are an acidic gas-absorbing liquid and an acidic gas reduction method that can reduce the energy required for recovering acidic gas from gas, even if the gas contains moisture, and that has little impact on solvent loss. The acidic gas-absorbing liquid according to the present invention reversibly absorbs and desorbs carbon dioxide, and contains an oxygen-containing polymer and an amine compound. The oxygen-containing polymer has at least one group selected from the group consisting of an oxyalkylene group, a carbonate group, and an ester group, and has a number average molecular weight of 250-20000, a boiling point of 200°C or higher, and a solubility parameter of 15.0 (MPa)1 / 2 or more and less than 19.5 (MPa)1 / 2. The amine compound has a solubility parameter of 13.0-25.5 (MPa)1 / 2.

The invention provides a method for efficiently synthesizing basic nickel carbonate, and belongs to the technical field of chemical preparation. Comprising the following steps: (1) preparing a mixed solution of sodium carbonate and sodium hydroxide; (2) under low-temperature and high-speed stirring conditions, dropwise adding a nickel salt solution into the mixed solution, adding a competitive adsorbent, adjusting the pH value of the solution, then heating, continuing stirring reaction, separating the competitive adsorbent by a magnet, centrifuging, washing and collecting prepared primary basic nickel carbonate; and (3) recrystallizing the primary basic nickel carbonate in an ethanol water solution, and drying to obtain the basic nickel carbonate. According to the preparation method disclosed by the invention, the content of impurity ions in the product is reduced, so that the high-purity basic nickel carbonate can be prepared, the synthesis efficiency is high, the production cost is relatively low, the method is green and environment-friendly, the competitive adsorbent can also be repeatedly utilized and recycled, the production cost is reduced, and the method has a wide application prospect.

The invention discloses a soluble alkaline salt scale inhibitor and a preparation method thereof, and belongs to the technical field of oilfield chemistry. The soluble alkaline salt scale inhibitor is prepared from amphiphilic modified graphene oxide, a surfactant, inorganic salt and deionized water, the amphiphilic modified graphene oxide contains a large amount of carboxyl groups, sulfonic acid groups, hydroxyl groups and the like, and has good metal ion chelating property; meanwhile, through the hydrophobic association effect and hydrogen-bond interaction between modified graphene grafted long carbon chains, the bonding probability between sodium ions of the soluble saline-alkali salt and bicarbonate radicals, carbonate radicals and chloride ions is further weakened, and through the synergistic effect of the amphiphilic modified graphene oxide, the surfactant and the inorganic salt, the salt scale inhibition effect is further improved; the method is especially suitable for soluble alkali salt water quality conditions of high temperature, high alkali and high salinity, can solve the problems of oilfield water injection, fracturing flowback strata and wellbore salt deposition, and has a good popularization prospect.

The embodiment of the invention discloses a water-gas interface greenhouse gas flux automatic monitoring system and a distribution prediction method. The system comprises a wind speed sensor and an air pressure and temperature sensor which are respectively used for collecting the wind speed of air at a monitoring point, the atmospheric pressure and the Kelvin air temperature; the infrared sensor is used for collecting the content of CO2, CH4 and N2O in the air of the monitoring point; the acidity sensor and the temperature sensor are respectively used for collecting the pH value and the centigrade water temperature of monitoring point water; the carbon dioxide sensor is used for collecting the concentration of bicarbonate in water at a monitoring point; the methane sensor and the nitrous oxide sensor are respectively used for collecting the contents of greenhouse gases CH4 and N2O dissolved in the monitoring point water; and the calculation module is used for calculating the flux of the greenhouse gas on the water-gas interface. According to the embodiment of the invention, the water-gas interface flux of various greenhouse gases under actual conditions can be accurately monitored.

The invention discloses a bio-based isosorbide carbonate plasticizer and a preparation method and application thereof, and relates to the technical field of plastic processing assistants.The preparation method of the bio-based isosorbide carbonate plasticizer comprises the steps that in the atmosphere of protective gas, diester carbonate and isosorbide serve as raw materials to be subjected to transesterification with a catalyst; and after the reaction is completed, carrying out post-treatment to obtain the isosorbide carbonate plasticizer. The isosorbide carbonate plasticizer disclosed by the invention can effectively reduce the melting temperature and melt viscosity of a material, improve the processability of the material, increase the flexibility of the material and improve the optical transmittance of the material. The preparation method disclosed by the invention has the characteristics of being simple in process, green and environment-friendly, easily available in raw materials, easy in catalyst separation and relatively high in product yield, and is an efficient and environment-friendly preparation process of isosorbide carbonate.

The invention provides a preparation method for improving the performance and carbon sequestration rate of a steel slag carbonized product, and the preparation method specifically comprises the following steps: (1) weighing the following raw materials in percentage by mass: 50-100 parts of steel slag powder, 13-17 parts of deionized water and 1 part of alcohol amine; (2) mixing the weighed deionized water with alcohol amine to obtain an alcohol amine solution, stirring the alcohol amine solution in a magnetic stirrer, continuously introducing CO2 gas with the concentration of 99.9% to carbonate the alcohol amine solution, and controlling the gas introduction time to be 2 hours; (3) doping an alkylol amine solution subjected to carbonation treatment into the weighed steel slag powder, and uniformly stirring by using a neat paste stirrer; (4) pressing the steel slag mixture into steel slag product briquettes in a compression molding manner; and (5) putting the briquette into a carbonization kettle, and introducing CO2 gas with the purity of 99.9% to prepare a steel slag carbonized product. The problem that the interior of the steel slag carbonized product cannot be fully carbonated and maintained is solved, so that the comprehensive performance and the carbon sequestration rate of the steel slag carbonized product are remarkably improved.

The invention discloses a method for recovering bisphenol A and cyclic carbonate by coupling polycarbonate with an epoxy compound, and belongs to the technical field of depolymerization and recovery of high polymer materials. The method comprises the following steps: constructing a reaction system comprising bisphenol A polycarbonate, an epoxy compound, Lewis acid, alkali and ionic liquid; placing the reaction system at the temperature of 70-150 DEG C in an air atmosphere, and carrying out a reaction for more than or equal to 10 min to obtain bisphenol A and cyclic carbonate; wherein the epoxy compound comprises at least one of styrene oxide, 1, 2-epoxypropane, 1, 2-epoxybutane, 1, 2-epoxydodecane, n-butyl glycidyl ether, epoxy propyl phenyl ether, 2-toluene glycidyl ether and 3-(1-naphthyloxy)-1, 2-epoxypropane, and the epoxy compound comprises at least one of styrene oxide, 1, 2-epoxypropane, 1, 2-epoxybutane, 1, 2-epoxydodecane, n-butyl glycidyl ether, epoxy propyl phenyl ether, 2-toluene glycidyl ether and 3-(1-naphthyloxy)-1, 2-epoxypropane; the alkali is inorganic alkali or organic alkali; the method is mild in reaction condition, high in resource utilization efficiency, good in operation safety and high in chemical monomer yield, and has a wide application prospect in the field of waste plastic treatment.

The invention provides a method for synthesizing cyclic carbonate by catalyzing conversion of carbon dioxide with a ZIF-8-coated In2O3 composite material, and belongs to the field of catalytic chemistry. According to the method, carbon dioxide and an epoxy compound are used as raw materials, a ZIF-8-coated In2O3 composite material is used as a catalyst, tetrabutylammonium bromide is used as a cocatalyst, cycloaddition of the epoxy compound and normal-pressure carbon dioxide is performed to synthesize cyclic carbonate, and the ZIF-8-coated In2O3 composite material is prepared by in-situ compounding of ZIF-8 and In2O3 of a hollow prism structure. The ZIF-8-coated In2O3 nano-composite catalyst provided by the invention is simple to prepare, the raw materials are cheap and easy to obtain, the catalytic performance is excellent, and high-selectivity synthesis of cyclic carbonate under mild conditions can be realized. In addition, the catalyst is stable in structure, easy to separate from a product and good in recycling performance, and belongs to an environment-friendly catalyst.

The invention provides a preparation method of mannitol carbonic acid sulfate, mannitol and dimethyl carbonate are used as starting raw materials to prepare mannitol carbonic acid sulfate, a target compound is obtained through ester exchange, cyclization and oxidation reaction, the raw materials are low in price and easy to obtain, the reaction operation is simple and convenient, the yield of the obtained product is 81% or above, the purity is 99.6% or above, and the method is suitable for industrial production. The method is suitable for industrial production.

The invention discloses preparation and application of an imido covalent organic framework material containing imidazolyl ionic liquid. The imido covalent organic framework material (ILs-TPN-COFs) containing the imidazolyl ionic liquid is obtained by connecting the imidazolyl ionic liquid [CnCmILs (at) Br] to an imido covalent organic framework TPN-COFs through a covalent bond. The material has an ionic liquid tertiary amine N active site and a halogen anion active site, and can promote CO2 activation and ring opening of epoxide. The ILs-TPN-COFs catalytic material has the advantages of uniform distribution of active sites, better stability, easiness in separation of the catalyst from a reaction system, better repeatability and the like. According to the invention, the prepared novel ILs-TPN-COFs material is applied to catalysis of synthesis of propylene carbonate from carbon dioxide and epoxypropane, and shows excellent catalytic performance under mild reaction conditions.

The invention relates to the technical field of mine water treatment, and discloses a treatment method of high-calcium-hardness mine water. The method comprises the following steps: (1) adjusting water chemical components of the mine water, so that the pH value of the mine water is 8-10, the mass ratio of sodium ions to calcium ions is 1: (4-8), the TDS is 7500-8000 mg / L, and the concentration of bicarbonate ions meets the following conditions: the required concentration of the carbonate ions is calculated according to the solubility product of calcium carbonate; the concentration of the bicarbonate ions is 90% twice the calculated concentration of the bicarbonate ions; and (2) adding gypsum into the mine water obtained in the step (1) to carry out first induced crystallization so as to remove calcium ions in the mine water. The method provided by the invention is used for treating the high-calcium-hardness mine water, can adapt to different inflow water qualities, and further improves the removal rate of calcium ions. The method provided by the invention can effectively ensure that the Ca < 2 + > content of the effluent quality of the mine water reaches the standard, can also reduce the secondary environmental pollution problem, and is low in energy consumption.

The present invention relates to a composition containing A) 60 to 93 wt. % of at least one aromatic polycarbonate, polyester carbonate or mixtures thereof, B) 2 to 20 wt. % of a polyester on the basis of an aromatic or cycloaliphatic dicarboxylic acid or mixtures thereof and cyclohexane dimethanol and optionally an additional aliphatic diol, and C) 1 to 20 wt. % of at least one phosphorus-containing flame retardant. The invention also relates to a component that contains the composition and to the use of components B and C in the indicated quantities in order to improve CTI and flame retardancy of polycarbonate compositions.

The invention belongs to the technical field of environmental engineering, and particularly relates to a method for enhancing the reaction efficiency of a Fenton-like fluidized bed through intelligent magnetic control. Specifically, customized composite magnetic particles are placed in a columnar Fenton-like fluidized bed reactor with an electromagnetic coil array distributed on the periphery, percarbonate activated by iron and aluminum phosphate is used as an oxidizing agent, and magnetic fields with different directions and intensities are applied to the magnetic particles by utilizing the electromagnetic coil array; the magnetic particles guide the fluid to form a required flowing form, and the fluid flowing path and the mixing process are highly accurately controlled, so that the aims of fully mixing the composite magnetic particles with the percarbonate ions, efficiently generating secondary oxidants such as hydroxyl free radicals, carbonate free radicals and superoxide anion free radicals and efficiently degrading pollutants are fulfilled.

The method for producing a carbonate bonded, compacted article comprises the steps of providing a particulate material which comprises a particulate carbonatable binder; compacting the particulate material to form a compact having pores which contain pore water; and carbonating said compact to produce carbonates including calcium carbonates thus transforming the compact into said carbonate bonded, compacted article. The carbonatable binder contains fluoride. In order to limit leaching of fluoride from the carbonated article a fluoride adsorbing, magnesium-bearing solid compound, which comprises surface hydroxyl groups bound to magnesium atoms, is provided in the compact. At least one magnesium-bearing additive is distributed in the particulate material prior to the carbonating step. This additive has a magnesium content of at least 30 wt.% MgO and comprises the fluoride adsorbing, magnesium-bearing solid compound and / or produces this fluoride adsorbing, magnesium-bearing solid compound in the particulate material by reaction in said pore water.

Adhesive compositions including a multivalent metal salt, an multidentate acidic organic compound, and an aqueous medium are disclosed. The multivalent metal salt and multidentate acidic organic compound can include, as a mixture, a carbonate salt and / or carbonic acid. The aqueous medium can include pH adjusting agent such as sodium hydroxide. The adhesive composition, upon curing, can have a porosity of 10-50%. The adhesive composition, upon curing, can include a plurality of pores. The adhesive composition can be porous, and upon curing can have a plurality of pores having a pore size of between 20 μm to 200 μm. Methods of producing the adhesive composition are disclosed. Methods of using the adhesive composition are further disclosed.

The invention discloses a method for preparing a carbonated nano-gelling activator through CO2 mineralization and a product and application of the carbonated nano-gelling activator, and belongs to the technical field of inorganic materials.The method comprises the steps that 1, a calcium source is extracted, specifically, the solid-phase calcium source and an extracting agent are mixed, and filtering is conducted after extraction to obtain a soluble calcium salt solution; (2) CO2 absorption: capturing CO2 gas by using an alkaline absorption liquid to fully dissolve CO2 to form a soluble carbonate solution; (3) calcium complexation: mixing a soluble calcium salt solution with an organic acid additive to obtain a complexed calcium precursor; and (4) carbonation: adding a soluble carbonate solution into the complex calcium precursor, terminating the reaction and separating the solid phase in the reaction solution when the mixed system generates a precipitate and is colloidal, cleaning by using a blocking agent, and drying to obtain the carbonated nano gelatinization activator. The carbonated nano gelling activator is high in gelling activity and can be used for synthesizing building materials with excellent mechanical strength, and a relatively high resource utilization level is realized.

The invention discloses polylactic acid polyol as well as a preparation method and application thereof. The preparation method comprises the following steps: performing a heating reaction on zinc salt, organic ammonium salt and bis (ethylene carbonate) ether to prepare an in-situ catalyst; anions of the organic ammonium salt are selected from any one of bromide ions, chloride ions and iodide ions; and adding a lactide monomer, and carrying out polymerization reaction to obtain the polylactic acid polyol. The polylactic acid polyol prepared by the invention has a flexible chain segment, can provide better flexibility, and can be applied to preparation of a polyurethane material.

Provided are an acidic gas-absorbing liquid and an acidic gas reduction method that can reduce the energy required for recovering acidic gas from gas and that has little impact on solvent loss. The acidic gas-absorbing liquid according to the present invention reversibly absorbs and desorbs carbon dioxide, and contains an oxygen-containing polymer and an amine compound. The oxygen-containing polymer has at least one group selected from the group consisting of an oxyalkylene group, a carbonate group, and an ester group, and has a number average molecular weight of 300-4000, a boiling point of 200°C or higher, and a solubility parameter of 19.5-26.0 (MPa)1 / 2. The difference between the solubility parameter of the oxygen-containing polymer and the solubility parameter of the amine compound is 4.0-6.3 (MPa)1 / 2.

The invention discloses a synthesis method of a hydrazine dicarboxylate modified cerium dioxide abrasive, and belongs to the technical field of precise polishing materials. The method comprises the following steps: taking cerous nitrate as a raw material, and preparing a cerous carbonate precursor through an ammonium carbonate precipitation reaction; and grinding and calcining the obtained precursor and hydrazine dicarboxylate to obtain the CeO2 grinding material with the surface rich in oxygen vacancies. And Ce < 4 + > can be partially reduced into Ce < 3 + > by reducing fragments generated by decomposition of the hydrazine dicarboxylate in the calcining process, so that an oxygen vacancy structure is formed through induction, and the chemical activity and the reaction rate of the abrasive are improved. The obtained grinding material shows excellent performance in chemical mechanical polishing (CMP) of K9 glass, the material removal rate (MRR) is increased by about 3.6 times compared with that of unmodified CeO2, the surface roughness (Ra) is reduced to about 0.16 nm or below, and grinding material particles are good in dispersity and less in agglomeration. The used hydrazine dicarboxylate is stable, low in toxicity and mild in reaction, and the particle size can be prevented from excessively growing while the high oxygen vacancy concentration is kept.

The invention relates to the technical field of saline-alkali soil improvement, and particularly discloses a preparation process and application of a multifunctional slow-release saline-alkali soil conditioner. The preparation process comprises the following steps: (1) uniformly mixing alginic acid powder, ardealite powder, carbon powder and water to form a wet material, then putting the wet material into a closed container, and carrying out heating and heat preservation treatment to obtain a precursor; and (2) standing the precursor at normal temperature, and then crushing the precursor to obtain the soil conditioner. The soil conditioner prepared by the process disclosed by the invention not only can more efficiently and quickly fix sodium, potassium, calcium and magnesium ions in soil, but also can reduce the content of carbonate ions, so that the salt content of the soil is reduced, and the alkalinity of the soil is reduced. In addition, the soil conditioner disclosed by the invention is also beneficial to relieving the alkali and salt returning phenomenon of the soil, and the use amount of the conditioner in the subsequent continuous soil improvement process is reduced.

Systems and methods for direct air capture of carbon dioxide or other gases utilize a calcium sorbent in a manner that allows for wide scale, relatively low cost implementation. In particular, a calcium sorbent may be provided as a substantially thin coating on one or more substrates and utilized for direct air capture of carbon dioxide through chemisorption. The carbonated sorbent may be disposed of for sequestration of the carbon dioxide or regenerated with capture of carbon dioxide released from the carbonated sorbent during the regeneration process.

The invention provides a method for preparing high-purity vanadium pentoxide from carbonation leachate. The method comprises the following steps: S1) carrying out silicon removal on the carbonation leachate, and carrying out solid-liquid separation to obtain silicon-removed slag and silicon-removed liquid; s2) mixing the post-silicon-removal liquid with a complexing agent, and reacting to obtain a post-reaction liquid; s3) carrying out vanadium precipitation on the reacted liquid to obtain ammonium metavanadate and vanadium precipitation wastewater; s4) oxidizing and calcining the ammonium metavanadate to obtain high-purity vanadium pentoxide; the complexing agent is selected from one or more of ethylene diamine tetraacetic acid, disodium ethylene diamine tetraacetate and tetrasodium ethylene diamine tetraacetate. According to the method, the leaching solution obtained through the vanadium slag low-calcium roasting-carbonation leaching vanadium extraction technology serves as the raw material, ions such as iron, calcium and magnesium are controlled to enter the vanadium product through complexing, high-purity vanadium pentoxide with the low impurity content is obtained, the technological process is simple, implementation is easy, the cost is low, and the method is one of the methods for preparing high-purity vanadium pentoxide through the carbonation leaching solution.

The invention provides a method for preparing Bayer stone based on a high-alpha-k sodium aluminate solution, and belongs to the field of aluminum oxide preparation. The method comprises the following steps: adding a morphology regulating agent into a sodium aluminate solution with set alpha k to obtain a mixed solution; introducing a mixed gas with a set CO2 volume concentration into the mixed solution to perform a carbonation reaction under a set condition, and obtaining Bayer stone slurry when a reaction system of the carbonation reaction reaches a set NK concentration; and carrying out solid-liquid separation on the Bayer stone slurry to obtain the Bayer stone. The method comprises the following steps: firstly, adding a morphological regulating agent into a sodium aluminate solution to regulate the growth process and morphological characteristics of crystals so as to reduce crystal defects and impurity content; secondly, the carbonation reaction rate and the product composition are controlled by controlling the carbonation reaction conditions; and finally, by accurately controlling the end-point caustic alkali concentration, the mixing of impurities in the forming process of the Bayer stone can be reduced, so that a high-purity Bayer stone product is obtained.

The invention relates to the technical field of soil remediation, in particular to a charcoal-fungus symbiont for a freeze-thaw environment and a preparation method and application of the charcoal-fungus symbiont. The preparation method of the charcoal-fungus symbiont comprises the following steps: crushing a biomass raw material, and carrying out pyrolysis to prepare basic charcoal; placing the basic biochar in an iron oxide solution, and carrying out an iron oxide loading reaction to obtain iron oxide biochar; the preparation method comprises the following steps: dipping iron oxide biochar in a chitosan solution for coating modification, then continuously adding a cross-linking agent for cross-linking solidification, and freeze-drying to obtain chitosan-iron oxide composite modified biochar; and immersing the chitosan-iron oxide composite modified biochar into a bacterial suspension of functional microorganisms, oscillating and adsorbing, and freeze-drying to obtain the carbon-bacteria symbiont. The invention aims to improve the heavy metal pollution phenomenon of soil and the soybean root rot disaster in the freezing and thawing cycle environment at the same time.