983 results about "Carbonic acid" patented technology

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 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 electrochemical machining, in particular to an electroplate liquid additive automatic supply control method based on conductivity monitoring data. The method comprises the steps that the temperature, the original conductivity and the carbonate concentration of electroplating liquid are obtained, an activation energy coefficient is determined based on the change trend of the original conductivity and the temperature, dynamic thermodynamic decoupling treatment is conducted on the original conductivity, and the net conductivity of the electroplating liquid is generated; according to the cumulative variation of the net conductivity in the historical time period and the total amount of the additive in the historical time period, the transmission inertia factor of the electroplating liquid is calculated in combination with the carbonate concentration, and the retardation risk index is determined based on the evolution trend of the transmission inertia factor, so that a PID control algorithm is reconstructed, and the supply amount of the additive is obtained; and performing automatic replenishment control based on the replenishment amount. According to the method, the accuracy of automatic supply control is improved by evaluating the degradation state of the bath solution components and self-adaptive integral saturation suppression.

The invention provides a battery and an electric device. A positive plate comprises a positive active material, and the positive active material is doped and / or coated with a lanthanum element; the surface of the diaphragm is coated with a ceramic coating; the electrolyte comprises a first solvent, a second solvent, a first additive and a second additive; the first solvent comprises a cyclic carbonate compound, the second solvent comprises a chain fluorosulfonamide compound, the first additive comprises mannitol carbonate sulfate, and the second additive comprises succinonitrile; the lanthanum element is doped / coated on the positive active material, so that the release of lattice oxygen at high voltage or high temperature can be effectively inhibited, and the exothermic reaction activity at the thermal runaway initial temperature is reduced; the first additive and the second additive in the electrolyte respectively form a compact CEI film and an SEI film with high thermal stability on the surfaces of the positive electrode and the negative electrode; the diaphragm ceramic coating provides a physical barrier, the thermal shrinkage temperature of the diaphragm is increased, and internal short circuit is prevented.

The invention relates to the technical field of industrial control, and discloses a soda water production line intelligent control method and system based on the Internet of Things, and the method comprises the steps: obtaining a backpressure valve reference pressure value according to the obtained real-time dynamic data through employing a pre-constructed carbonation digital twin model, and calculating the backpressure valve reference pressure value according to the backpressure valve reference pressure value; the carbonation digital twinning model is set to obtain a theoretical pressure value by adopting the Henry law according to the target gas content and the real-time data of the mixed liquid temperature, and obtain a predicted pressure value by adopting the pre-constructed pressure prediction model according to the target gas content, the real-time data of the raw material liquid injection flow and the real-time data of the carbon dioxide injection flow; further obtaining a reference pressure value of the back pressure valve; according to a first difference value between the target gas content and the real-time gas content of the mixed liquid, a first feedback correction algorithm is adopted to correct the reference pressure value of the back pressure valve, and a dynamic pressure control instruction of the back pressure valve is obtained; and controlling the back pressure valve to execute the back pressure valve dynamic pressure control instruction. According to the method, the taste stability of the soda water is effectively improved.

The invention discloses a method for reducing the content of rare earth carbonate oil, which comprises the following steps: adding rare earth carbonate seed crystals and pure water into a precipitation tank, feeding a rare earth chloride solution after extraction separation into the precipitation tank, adding an ammonium bicarbonate solution, and carrying out precipitation reaction to obtain rare earth carbonate; the method comprises the following steps: treating rare earth carbonate with hydrochloric acid, converting into a rare earth chloride solution, and filtering the rare earth chloride solution to remove oil to obtain a refined rare earth chloride solution; adding rare earth carbonate into a precipitation tank as a seed crystal, adding the refined rare earth chloride solution and the prepared ammonium bicarbonate solution into the precipitation tank, and carrying out precipitation reaction to produce oil-free rare earth carbonate. According to the invention, oil entrained in the extraction feed liquid and oil dissolved in the feed liquid can be removed, and the quality of the rare earth carbonate product is improved.

The present invention relates to a method of producing a carbonated composite:a. providing a particulate mineral material, wherein the mineral material comprises metal slag, wherein the metal slag comprises steel slag;b. providing a modifier, wherein the modifier comprises sodium gluconate;c. mixing the mineral material and the modifier with water to form a slurry;d. treating the slurry with carbon dioxide, to form a wet solid residue, wherein the concentration of carbon dioxide is greater than about 10 vol%; ande. drying the wet solid residue to form the carbonated composite.

The invention relates to a method for recovering lithium and fluorine from aluminum electrolysis hazardous waste, which comprises the following steps: firstly, mixing organic polyol and alkaline hydroxide according to a molar ratio of 1: (0.5-2) to obtain a eutectic solvent; heating the eutectic solvent to 80-150 DEG C, and adding a proper amount of raw material fine powder and calcium oxide for reaction leaching; carbonating and filtering the leachate to obtain lithium carbonate; washing the leaching residues with an acetic acid solution to obtain a calcium fluoride product; the concentration of fluorine ions in the leachate is smaller than or equal to 200 ppm, and the purity of calcium fluoride is larger than or equal to 90%; the leaching rate of lithium in the method is greater than 85%; the slag feeding rate of fluorine is greater than 95%; and no hydrogen fluoride gas is generated in the method. According to the method, a non-toxic and biodegradable eutectic solvent is adopted as a leaching agent, and efficient leaching of lithium and fluorine in the aluminum electrolysis dangerous waste materials is achieved; calcium oxide is used as a precipitating agent, free fluorine is promoted to be precipitated and recycled as calcium fluoride, the whole process meets the requirement of green metallurgy, and the win-win situation of resources and the environment is achieved.

The invention discloses a preparation method and application of a multimode luminescent cesium yttrium chloride lead-free perovskite luminescent material. In the specific synthesis process, firstly, precursor materials-cesium carbonate, yttrium carbonate and cerium acetate are dissolved in a mixed solution of glacial acetic acid and hydrochloric acid, and a precursor solution is obtained; then dissolving a certain amount of antimony acetate with acetonitrile to form an anti-solvent solution; and finally, adding the precursor solution into the anti-solvent solution to obtain the Sb / Ce double-doped cesium yttrium chloride lead-free perovskite luminescent material. During application, the Cs3YCl6 Sb and the Cs3YCl6 Sb / Ce luminescent materials are combined for use to form a pattern, and protected information can be decrypted through a specific excitation wavelength. According to the invention, the cesium yttrium chloride lead-free perovskite luminescent material capable of realizing multimode luminescence can be prepared in a short time.

The invention provides a high ventilation method for maintaining equal carbonic acid through exogenous CO2 gas and a breathing device. Belongs to the technical field of gas exchange. The method comprises the steps that physiological monitoring data of a patient are collected in real time, and meanwhile parameters of a breathing machine are obtained; inputting the collected data into a pre-trained time sequence prediction model; performing data fusion based on the EtCO2 predicted value, the currently actually measured physiological data and the static parameters of the patient to form a comprehensive evaluation result; and through a control algorithm, an incremental adjustment instruction of the exogenous CO2 supplementary flow is obtained through calculation based on the comprehensive evaluation result. The CO2 demand is estimated in real time through a dynamic prediction model, static estimation is replaced, and the control accuracy and the response speed are remarkably improved; through a multi-modal data fusion technology, dynamic and static physiological parameters are comprehensively applied, so that a control strategy can better reflect the individualized physiological status of a patient.

The invention discloses a preparation method and application of a catalyst based on pyridine ionic liquid, and belongs to the technical field of catalyst preparation. According to the invention, a hydrolysis reaction of a silane coupling agent is utilized to prepare a silicon oxide nanotube containing a pyridine unit, and then a quaternization reaction is carried out to obtain the catalyst based on the pyridine ionic liquid. The catalyst has a high specific surface area and a rich pore channel structure, exposure of active sites and contact of the active sites and reactants are facilitated, and the catalytic rate is increased. Meanwhile, the silicon oxide nanotube contains hydroxyl, and can cooperate with a pyridine ionic liquid site to catalyze a carbon dioxide cycloaddition reaction. The obtained catalyst can catalyze the reaction of carbon dioxide and an epoxy compound to prepare cyclic carbonate under solvent-free and metal-free conditions, and the catalyst is easy to recover and simple in product purification, and has a good application prospect.

The invention relates to a method and a system for preparing chloroethylene carbonate through continuous photochlorination. The system aims at solving the three technical problems that the mass transfer efficiency of chlorine is low under the high gas-liquid ratio, reaction balance is inhibited by accumulation of hydrogen chloride by-products, and selectivity is reduced due to excessive chlorination. The method provided by the invention comprises the following steps: dispersing chlorine into bubbles of 50 microns or below by adopting a metal sintering microbubble generator; a light source and a hollow fiber membrane separation assembly are arranged in the reactor, chlorine and ethylene carbonate are subjected to a reaction through photo-initiation to generate chloroethylene carbonate, and meanwhile generated hydrogen chloride is removed through membrane in-situ displacement by means of purging gas; the system adopts a two-section series structure, and the reaction depth is cooperatively controlled through sectional chlorine gas introduction and gradient illumination intensity. The method provided by the invention realizes efficient utilization of chlorine, real-time breaking of reaction balance and high-selectivity synthesis of monochlorinated products, and is suitable for continuous, safe and efficient industrial production of chloroethylene carbonate.

The invention discloses an environment-friendly degradable plastic packaging bag and a preparation method thereof, belongs to the technical field of packaging bag preparation, and is used for solving the technical problem that the degradation capability and the mechanical property of an environment-friendly packaging bag in the prior art need to be further improved. According to the invention, the prepared carbonic acid bridged compact polyester is used as a main body skeleton to provide strength and film-forming property, silica acetal hybrid polysaccharide is introduced to form a compact and complex diffusion path inside and reduce gas and moisture permeation, and then active side chain polyamino acid is added to adjust interfacial compatibility and enhance structural stability, so that the film-forming property is improved. Through reasonable combination of the three components, the environment-friendly packaging bag keeps high tensile strength and tearing strength, meanwhile, the barrier property is remarkably improved, and gradual complete degradation is achieved in compost and soil environments.

The application discloses a preparation method and purification process of copper hydroxide, a certain amount of anhydrous copper sulfate is accurately weighed, and a certain volume of deionized water is added to prepare a solution with a certain concentration, a copper ammonia solution is prepared: slurry is prepared from circuit board sludge, screening is performed, ammonium bicarbonate or ammonium carbonate is added for reaction, and a copper ammonia solution containing carbonate or bicarbonate is obtained through purification; in addition, high-purity copper powder is added into concentrated ammonia water, concentrated hydrogen peroxide solution is slowly dropped into the concentrated ammonia water, and the dropping is continued until no large amount of bubbles is generated in the solution, and the solution is filtered to obtain a clear indigo blue solution. The production process adds the step of adding a stabilizer and stirring, guarantees the stable state of the copper hydroxide crystal, and enables the copper hydroxide crystal to remain unchanged into copper oxide for one year in an environment with a temperature as high as 60 degrees.

The application discloses an alkali ion type covalent organic framework material and a preparation method and application thereof, wherein 2,4,6-tris(4-formylphenyl)-1,3,5-triazine, 1,4-diisocyanobenzene and 2-aminopyridine are used as building units, a covalent organic framework containing pyrimidine is obtained through a condensation reaction, and then a quaternary ammonium reaction and an ion exchange reaction are sequentially performed to obtain the alkali ion type covalent organic framework.The alkali ion type covalent organic framework material prepared by the application has rich alkali sites, developed pore structures and good chemical stability, exhibits good catalytic performance as a catalyst for one-pot preparation of dimethyl carbonate from CO2, an epoxide compound and methanol, and also shows good cycle stability.

The invention relates to the technical field of soda wine preparation, in particular to a method and extraction equipment for preparing roselle soda wine from roselle extract.The method comprises the steps that dried roselle is subjected to low-temperature crushing and then extracted with an alcohol-water solution with the temperature controlled in stages, and a crude extracting solution is obtained; vitamin C and sodium citrate are compounded and stabilized, clarification and filtration are carried out, and a roselle extracting solution with stable color and flavor is obtained; and then scientifically blending with brandy base liquor, vodka, high fructose corn syrup, prebiotic syrup and other ingredients, finally carbonating with 0.5 volume of carbon dioxide at low temperature, and carrying out cold filling at the temperature of less than or equal to 4 DEG C to obtain a finished product. The problems that the extraction efficiency of natural flower raw materials is low, flavor and functional components are difficult to retain, and the fusion stability of an extract and a soda wine system is poor are effectively solved, and the comprehensive quality improvement that the product is outstanding in natural flavor, stable in color and luster, fine and lasting in bubble, healthy in function and good in drinking suitability is achieved.

The application discloses a kind of carbon dioxide methyl ester raw gas purification filter pollution devices, it includes horizontally arranged cylinder, coaxial tower type ladder filter assembly and translation pneumatic purging assembly are arranged in the cylinder, the tower type ladder filter assembly includes several end face filter parts and cylinder filter parts that are alternately connected in sequence;The beneficial effects of the application: the tower type ladder filter assembly of the application is designed to filter carbon dioxide methyl ester raw gas, the tower structure can effectively increase the filter area, thereby improving the filtering efficiency;Tower type ladder filter assembly has matching end face filter parts and cylinder filter parts, with axial airflow and radial airflow filtering function, according to the gas direction to axial filtration as main, radial filtration as auxiliary, long service life;According to the actual use characteristics of end face filter parts and cylinder filter parts, design translation pneumatic purging assembly and spray cleaning assembly to clean tower type ladder filter assembly, cleaning is fast and efficient.

The invention discloses a synthesis method of mannitol carbonate sulfate, and belongs to the technical field of organic synthesis. The synthesis method provided by the invention comprises the following steps: reacting 1, 3, 4, 6-tetrachloro-2, 5-hexanediol with chlorosulfonic acid in the presence of an acid-binding agent to obtain an intermediate solution as shown in a formula (II); formula (II); and mixing the intermediate solution as shown in the formula (II) with anhydrous carbonate, heating to a first set temperature for reaction, and then heating to a second set temperature for reaction in the presence of a phase transfer catalyst to obtain the mannitol carbonic sulfate. The whole process route is short, the yield is high, and the total yield of two steps reaches 88% or above; meanwhile, few by-products are generated, the purification difficulty is low, the reaction time is short, few hazardous wastes are generated, operation is easy and convenient, and industrial large-scale production is facilitated.

This application belongs to the field of electrolytic manganese preparation technology, specifically providing a method for preparing electrolytic manganese from manganese carbonate ore through dry polishing pre-selection and multi-stage purification, including the following steps: a) crushing and screening the manganese carbonate ore to obtain ore of a first particle size; b) subjecting the ore of the first particle size to dry strong magnetic separation pre-selection and tailings removal to obtain pre-selected concentrate; c) grinding the pre-selected concentrate to obtain a grinding product of a second particle size; d) mixing the grinding product with water or return liquid for slurry treatment to obtain a slurry; e) mixing the slurry with sulfuric acid for chemical leaching to obtain a leaching slurry; f) subjecting the leaching slurry to multi-stage purification treatment to obtain a purified electrolyte; g) electrolyzing the purified electrolyte to obtain cathode electrolytic manganese. The electrolytic manganese obtained by this application has the advantages of high purity, low water load, and low reagent consumption.

Provided is a polishing composition that makes it possible to achieve a higher polishing removal rate in a composition containing a permanganate. Provided is a polishing composition containing a permanganate and a zirconium carbonate compound.

The present application relates to a kind of preparation method of trifluoromethyl pyrazole compound, belong to the technical field of organic synthesis.The specific method is: (1) trifluoroacetyl ethyl acetate is first with hydrazine hydrate cyclization reaction and generates compound of formula III;(2) under the catalysis of base, compound of formula III is reacted with difluoromethylation reagent and generates compound of formula II;(3) compound of formula II is reacted with methylating agent and obtains compound of formula I;The difluoromethylation reagent is difluoro-monochloromethane or sodium difluoro-monochloroacetate;The methylating agent is chloromethane, bromomethane, iodomethane, dimethyl sulfate or dimethyl carbonate.The present application is prepared by changing reaction route, and the higher-priced raw material methylhydrazine is replaced, and isomer impurity is no longer generated in the product prepared.Not only raw material cost is reduced, but also the purity of product is improved.

The present invention relates to a process for binding carbon dioxide to a waste building material 10, wherein the reaction is carried out in a carbonation reactor 20, wherein a waste building material 10 is fed to the carbonation reactor 20, wherein a carbon dioxide-containing gas 30 is fed to the carbonation reactor 20, and wherein a carbonation product 50 is discharged from the carbonation reactor 20, characterized in that the alkaline earth content of the waste building material 10 fed to the carbonation reactor 20 and / or of the carbonation product 50 discharged from the carbonation reactor 20 is determined by means of elemental analysis 60, wherein the degree of carbonation C of the carbonation product 50 is determined by IR spectroscopy, and wherein a carbonation degree limit value Cmax is set.wherein if the carbonation degree limit Cmax is undershot, the supply of the waste material 10 to the carbonation reactor 20 is reduced and / or the supply of the carbon dioxide-containing gas 30 to the carbonation reactor 20 is increased, wherein if the carbonation degree limit Cmax is exceeded, the supply of the waste material 10 to the carbonation reactor 20 is increased and / or the supply of the carbon dioxide-containing gas 30 to the carbonation reactor 20 is reduced.

The application discloses a method for rapidly and harmlessly treating phosphogypsum, and particularly relates to the harmless treatment technical field of industrial solid waste. The method comprises the following steps: mixing raw materials with an alkaline neutralizing agent, a trapping agent and an activating agent, adding a phosphorus solidifying agent and a fluorine solidifying agent, mixing, carbonizing and aging, and obtaining harmless phosphogypsum. The method adopts the alkaline neutralizing agent to rapidly neutralize free acid and improve the pH of the system; the trapping agent adsorbs heavy metals; the activating agent promotes As, Cd and the like to form a difficult-to-dissolve iron oxide gel or a precipitate; the phosphorus solidifying agent and the fluorine solidifying agent perform deep chemical precipitation to form a stable iron-calcium-phosphate / ferric fluoride composite solidified body. The functions of the agents are clear, and the agents have synergistic effects; the solidification effect of the agents on high water-solubility phosphorus, fluorine and various heavy metals is far better than that of a single or simply compounded agent system; and the leaching concentration can be reduced to a level far lower than the national standard.

The present invention provides a carbonation treatment system and a carbonation treatment method that can obtain granules having a desired particle size in high yield. [Solution] The carbonation treatment system 10 comprises a carbonation device 1 that carbonizes a material to be treated F by bringing it into contact with carbon dioxide gas to produce a carbonated product P, a granulation device 2 that granulates the carbonated product P transported from the carbonation device 1, and a moisture content adjustment mechanism 3 that adjusts the amount of moisture added to the carbonated product P.

The invention relates to compositions containing selenite-containing compounds and pharmaceutically acceptable acids, selected from citric acid, acetic acid, malic acid, carbonic acid, sulphuric acid, nitric acid, hydrochloric acid, fruit acids or mixtures thereof, for use for treating cervical inflammations, dysplasia and / or carcinomas. The invention further relates to methods of using such compositions.

Provided is a method for separating impurities and cobalt without using an electrolysis process from a cobalt chloride solution containing impurities and producing a high purity cobalt sulfate. The production method for cobalt sulfate includes: a copper removal step (S1) of adding a sulfurizing agent to a cobalt chloride solution containing one or more impurities of copper, zinc, manganese, calcium, and magnesium and generating a precipitate of sulfide of copper to separate to remove copper; a neutralization step (S2) of adding a neutralizer or a carbonation agent to a cobalt chloride solution having undergone through the copper removal step (S1) and generating cobalt hydroxide or basic cobalt carbonate to separate magnesium; a leaching step (S3) of adding sulfuric acid to the cobalt hydroxide or the basic cobalt carbonate to obtain cobalt sulfate solution; and a solvent extraction step (S4) of bringing an organic solvent containing an alkyl phosphoric acid-based extractant to the cobalt sulfate solution and extracting zinc, manganese, and calcium into the organic solvent to separate to remove zinc, manganese, and calcium. These steps are sequentially executed.

This invention provides a water-resistant, non-isocyanate-based polyurethane adhesive, its preparation method, and its applications. The adhesive features a cross-linked network structure obtained by reacting a trifunctional five-membered cyclic carbonate with tris(2-aminoethyl)amine; the trifunctional five-membered cyclic carbonate has the structure shown in Formula I. This non-isocyanate-based polyurethane adhesive is suitable for a wider range of environmental conditions and applications. It can be used not only in dry environments but also maintains good adhesion performance in humid, high-humidity, and even underwater environments, unaffected by moisture. Even after being submerged underwater for a period of time, its adhesive strength after removal and air drying is still similar to that of the unsubmerged sample, thus meeting the bonding requirements in humid environments, such as bonding items in bathrooms, kitchens, and outdoor construction. This expands the application field of polyurethane adhesives, providing a more reliable solution for various industrial and civilian bonding needs.

The utility model relates to the field of catalyst recycling technology, especially relates to a carbonic acid dimethyl ester synthesis is with catalyst recycling device. Including recovery jar, the recovery jar is installed with the stirring assembly for stirring catalyst, the recovery jar is installed with the heating assembly for heating catalyst, recovery assembly is installed on the recovery jar for recycling the hot air of discharge, the utility model discloses through the setting of recovery assembly, and the recovery jar exhausts the hot and humid gas and exchanges heat with the outside air in the heating box, and the preheating of air is carried out, thereby reducing the temperature difference of the air that advances the wind and heats to dry exhaust air, realizes the recycling of the waste heat in the hot and humid gas, reduces the energy waste that the direct discharge of heat causes, and reduces the energy consumption cost of heating process.

The application belongs to the technical field of chemical synthesis, and particularly relates to a preparation method of diisopropyl peroxydicarbonate and application of the diisopropyl peroxydicarbonate. The preparation method comprises the following steps: firstly, isopropyl chloroformate and an ester-soluble organic solution are added into a three-necked flask, stirring is started, hydrogen peroxide solution is added, when the temperature of the mixture in the flask is stabilized at-5 DEG C, sodium hydroxide solution is slowly added into the three-necked flask, and the time and temperature in the reaction process are controlled; finally, the organic phase is separated, washed with water, dried with anhydrous sodium sulfate, and obtained. The preparation method is safe and controllable, the yield of the diisopropyl peroxydicarbonate is high, the stability is good, the diisopropyl peroxydicarbonate can be directly used for the preparation of polyvinylidene fluoride, a chain transfer agent is not needed, polymerization can be carried out under low-temperature conditions, the molecular chain regularity of the polyvinylidene fluoride is improved, abnormal structures are few, the crystallinity is high, and the comprehensive performance is good.

The utility model discloses a device for preparing calcium carbonate and calcium sulfate from desulfurized fly ash through wet carbon sequestration. Comprising a lime kiln, a lime digestion and emulsification tank, a leaching tank, a first filtering unit, a second filtering unit, a third filtering unit, a fourth filtering unit, a purification reaction kettle, a carbonization and oxidation reaction kettle, a light calcium synthesis reaction kettle, a calcium carbonate synthesis reaction kettle, a common calcium carbonate drying unit, a calcium sulfate drying unit and an ammonia chloride solution buffer tank, the first recovery tank is used for collecting ammonia gas escaped from the leaching tank, the first filtering unit, the purification reaction kettle, the second filtering unit, the third filtering unit and the calcium sulfate synthesis reaction kettle and supplying the ammonia gas to the light calcium synthesis reaction kettle. The ammonia gas is used for adjusting the PH, so that carbon dioxide is dissolved in water to form carbonic acid, and carbonate reacts with calcium ions to form calcium carbonate. And the escaped ammonia gas is collected and reused. The ammonia gas utilization rate is improved. And the consumption of ammonia gas is reduced.