1200results about "Calcium/strontium/barium carbonates" patented technology

According to the invention, biomass rice hull ash and a sodium hydroxide solution are reacted to obtain water glass and carbon mud. And reacting the water glass with CO2 generated by calcining the limestone to produce a white carbon black product and a mixed waste liquid of sodium carbonate and sodium bicarbonate. Meanwhile, quick lime obtained by calcining limestone is digested and then reacts with sodium carbonate and sodium bicarbonate mixed waste liquid to generate a light calcium carbonate product and dilute sodium hydroxide waste liquid. And finally, the dilute sodium hydroxide waste liquid is concentrated and reused for water glass production, so that the waste liquid is recycled, and a complete process closed loop is formed. According to the process method disclosed by the invention, two leading-edge innovative processes, namely production of white carbon black by renewable resource biomass rice hull ash and production of white carbon black by a carbonization method, are organically combined and are coupled with production of light calcium carbonate by a limestone calcination process, so that the problem that a large amount of sodium sulfate-containing wastewater is discharged in a traditional process is solved; meanwhile, the carbon footprint of white carbon black and calcium carbonate products is greatly reduced.

The invention relates to the technical field of nano materials, and particularly discloses a preparation method of surface modified nano calcium carbonate for a battery diaphragm coating. According to the method, the technical paths of microemulsion confinement crystal form regulation and control, gradient surface modification and boehmite compounding and porosity regulation and control are fused, and the functional nano calcium carbonate adaptive to the battery diaphragm coating is prepared. According to the technical scheme, limestone is used as a raw material, after calcination and digestion, the particle size of nano calcium carbonate is controlled through microemulsion carbonization (a cyclohexane-span 80-n-butyl alcohol system); a silane coupling agent KH560-KH570 is adopted for gradient modification to introduce an electrophilic functional group, boehmite is compounded to form a composite coating, and the porosity is regulated and controlled by adjusting the solid content in coating slurry and the coating speed. The method is stable in process and high in compatibility, and meets the requirements of diaphragm coatings of lithium ion batteries and solid-state batteries.

A method of capturing carbon dioxide, including providing a particle containing magnesium oxide, calcium oxide, or a combination thereof; and providing a mixture gas to contact the particle, wherein the mixture gas includes water vapor, carbon dioxide, and nitrogen oxide, and the particle captures the carbon dioxide to form a carbonated particle and a treated gas. The mixture gas has a relative humidity of 25% to 95%, a nitrogen oxide concentration of 20 ppm to 2000 ppm, and a carbon dioxide concentration of 0.05% to 15%.

The invention relates to a method for decalcification and carbon sequestration of fly ash water washing liquid. According to the method, the extraction effect of insoluble organic amine on acid is utilized to improve the pH value of a water washing liquid system, CO2 is continuously absorbed, and calcium in the fly ash water washing liquid is completely removed; the amine in the organic phase is regenerated through alkali, and meanwhile, a small amount of organic diluent mixed in the water washing liquid is separated from low-boiling-point azeotrope containing the organic diluent at the tower top through azeotropic distillation, so that recycling is realized. The prepared calcium carbonate product is small in particle and high in purity, is a high-quality vaterite type calcium carbonate particle, can be used as a very good adsorbent and additive material, and has wide application in multiple fields.

The invention discloses acid-resistant calcium carbonate and a preparation method thereof, and belongs to the technical field of calcium carbonate filler production. According to the invention, industrial waste carbide slag is used as a calcium source, and calcium hydroxide slurry is obtained through impurity removal; then adding sodium polyacrylate and sodium hexametaphosphate, stirring and dispersing, then introducing carbon dioxide for carbonization, adding a surfactant for ultrasonic activation after carbonization, and finally sequentially adding zirconium oxychloride and sodium silicate to prepare the acid-resistant calcium carbonate. The defects of traditional silicon dioxide and titanium dioxide coated calcium carbonate products are overcome, the prepared calcium carbonate product is compact and uniform in coating layer and good in stability, meanwhile, excellent acid resistance and mechanical property are considered, the calcium carbonate can be suitable for more acid environments, and the application range of calcium carbonate is effectively widened.

The present invention relates to the technical field of industrial solid waste utilization, and specifically relates to an ore dissolving device and method. The ore dissolving device comprises a tank body, and an ore dissolving area, a ore-dissolving slag removal area, an iron and aluminum removal area and a leaching solution storage area, which are sequentially arranged in the tank body from top to bottom, wherein the bottom of the ore dissolving area is in communication with the ore-dissolving slag removal area; a plurality of first overflow pipes are evenly provided in the ore-dissolving slag removal area, one end of each first overflow pipe is in communication with the ore-dissolving slag removal area, and the other end thereof is in communication with the iron and aluminum removal area; a plurality of second overflow pipes are evenly provided in the iron and aluminum removal area, one end of each second overflow pipe is in communication with the iron and aluminum removal area, and the other end thereof is in communication with the leaching solution storage area; and one or more precipitant sprayers are also provided above the iron and aluminum removal area. The ore dissolving device of the present invention can not only fully leach calcium from magnesium slag, with a calcium extraction rate of 90% or higher, but can also effectively remove impurities such as iron and aluminum in an ore dissolving solution, thereby improving the purity of calcium ions in a leaching solution.

A method of capturing carbon dioxide, including providing a particle containing magnesium oxide, calcium oxide, or a combination thereof; and providing a mixture gas to contact the particle, wherein the mixture gas includes water vapor, carbon dioxide, and nitrogen oxide, and the particle captures the carbon dioxide to form a carbonated particle and a treated gas. The mixture gas has a relative humidity of 25% to 95%, a nitrogen oxide concentration of 20 ppm to 2000 ppm, and a carbon dioxide concentration of 0.05% to 15%.

To provide a method which enables inexpensive production with a high yield of lithium hydroxide with a low amount of impurities such as sodium from lithium-containing water including a lithium ion and a chloride ion.SOLUTION: A production method of lithium hydroxide includes: a crystallizing step of crystallizing lithium hydroxide (LiOH) from lithium-containing water including a lithium ion and a chloride ion; a solid-liquid separation step of performing solid-liquid separation treatment of concentrated liquid including the LiOH to obtain the LiOH as a solid product and filtrate; a carbonation step of producing lithium carbonate from the filtrate by carbonation; a lithium carbonate recovery step of evaporating at least a part of ammonia from a mixed liquid obtained in the carbonation step and performing solid-liquid separation treatment of the resultant treated liquid to obtain lithium carbonate as a solid product; a lithium hydroxide production step of converting the obtained lithium carbonate into LiOH followed by solid-liquid separation treatment to obtain an aqueous LiOH solution (1) as a liquid component; and a recrystallizing step of crystallizing LiOH from the aqueous solution (1).SELECTED DRAWING: Figure 2

The invention discloses a preparation method of a porous nano calcium carbonate filler. The preparation method comprises the following steps: (1) preparing an additive solution I; (2) preparing an additive solution II; (3) preparing an adding solution III; and (4) uniformly mixing a calcium salt solution, the additive solution I, the additive solution II and the additive solution III, then adding a carbonate solution in a stirring state, rapidly stirring until no precipitate is generated after material adding is completed, then carrying out solid-liquid separation, washing a solid phase with deionized water, washing with ethanol, and drying to obtain the porous nano calcium carbonate filler. The nano calcium carbonate filler prepared through the method is of a porous structure, good in dispersity and high in specific surface area, and the performance of a composite material can be remarkably improved when the nano calcium carbonate filler serves as the filler.

The invention relates to the technical field of water treatment, and discloses a method for circularly inducing crystallization, hardness removal and desalination of calcium carbonate. Adding the seed crystal into high salt water; adding sodium hydroxide into the heavy salt water; adding sodium carbonate to generate a supersaturated solution; introducing the solution containing the calcium carbonate crystal nucleus into crystallization equipment; treating the reacted solution through solid-liquid separation equipment; further desalting the water body subjected to hardness removal by adopting a membrane separation mode; collecting and treating the formed calcium carbonate precipitate, and recovering the precipitate by adopting a separation technology; by adopting the synthesized vaterite type seed crystal, the hardness removal and desalination efficiency is remarkably improved in the cyclic induced crystallization process of calcium carbonate. Compared with the traditional non-synthetic seed crystal, the synthetic seed crystal has higher surface area and uniformity, so that the combination of calcium ions and carbonate ions can be more quickly induced to form a stable crystal nucleus, and the overall effect of the reaction is finally improved.

The invention discloses a method for realizing pollution reduction and carbon reduction by phosphogypsum recycling. The method comprises the following steps: (1) washing phosphogypsum with water to remove soluble impurities, neutralizing residual acid, and calcining and activating; (2) pretreatment of the landfill leachate: magnesium salt and phosphate are added, the pH of the landfill leachate is adjusted, and free ammonia NH3 is released through low-temperature heating; (3) the pretreated landfill leachate is sprayed to capture CO2 in the flue gas, and a (NH4) 2CO3 solution is obtained; (4) fully mixing a (NH4) 2CO3 solution with the pretreated ardealite, and controlling the reaction conditions in a closed reactor, so that the ardealite and (NH4) 2CO3 are subjected to a heterogeneous reaction to generate CaCO3 and (NH4) 2SO4; and (5) product purification: carrying out solid-liquid separation on the mixed solution by adopting a multi-stage crystallization process to obtain a building material, and carrying out gradient cooling and recrystallization purification on the filtrate to obtain the nitrogen fertilizer. According to the method, recycling of the landfill leachate and the ardealite is achieved, and CO2 in the flue gas is efficiently removed.

The invention relates to the technical field of barium carbonate preparation, and provides a barium carbonate synthesis reactor and an application method thereof.The barium carbonate synthesis reactor comprises a tower body, a reaction pipe, a flow guide pipe and a sprayer, and the tower body, the reaction pipe and the flow guide pipe are coaxially arranged; the reaction tube is positioned in the tower body, and one end of the reaction tube extends out of the tower body; the flow guide pipe is located in the reaction pipe, and the flow guide pipe and the reaction pipe form a turbulent flow part used for reducing the gas flow rate and discharging reaction gas; the spray head is arranged on the reaction tube, and the spraying end of the spray head is positioned in the reaction tube and corresponds to the turbulent flow part. The reaction pipe and the flow guide pipe are arranged in the tower body, the reaction pipe extends out of the tower body, carbon dioxide gas can be conveniently input, and the flow guide pipe can conduct gas flow guide, so that the carbon dioxide gas can fully react with a barium sulfide solution sprayed by the spray heads on the periphery of the reaction pipe; meanwhile, the flow guide pipe is also used for outputting gas, so that gas output in the tower is realized, and the device is suitable for preparing barium carbonate by taking a barium sulfide solution as a raw material.

The invention provides a garbage pyrolysis gasification multi-stage directional regulation-gas-solid phase reforming synergistic hydrogen production treatment process which comprises the following steps: first-stage regulation: pretreatment and graded feeding: crushing, sorting, drying and catalytic coating treatment are performed on garbage through a physical-chemical directional means; second-stage regulation and control: performing low-temperature pyrolysis directional dechlorination, and performing thermochemical directional conversion on plastic and biomass garbage at 350-450 DEG C; third-stage regulation and control: gasifying and melting are coordinated and oriented, and a gas-solid phase coupling reaction is realized in double fluidized beds at 800-900 DEG C; four-stage regulation and control: multi-stage gas-solid phase reforming is carried out, and the hydrogen yield is increased through catalysis-adsorption synergistic effect in a 700 DEG C moving bed; and five-stage regulation and control: deep purification and hydrogen purification, wherein the synthesis gas is selectively oxidized by utilizing chemical looping combustion to release hydrogen with the purity being greater than or equal to 99.99%. According to the invention, the molten ash is used as a catalytic carrier, and the Fe-Ce active sites of the molten ash are utilized to synchronously realize tar cracking and synthesis gas reforming, so that the conversion rate of tar is effectively improved.

This invention provides a method for preparing monodisperse nano-calcium carbonate from calcium-containing industrial solid waste. The method comprises the following steps: S1: mixing calcium-containing solid waste and an ammonium salt solution, reacting the mixture, and filtering to obtain a calcium-containing filtrate; S2: mixing the calcium-containing filtrate, CO2 gas, and a crystal form control agent, reacting the mixture, and filtering to obtain nano-calcium carbonate; S3: mixing the nano-calcium carbonate with an aqueous solution containing a surfactant, reacting the mixture, centrifuging, washing, and drying to obtain monodisperse nano-calcium carbonate. This method improves the calcium leaching rate from calcium-containing solid waste, achieves explosive nucleation and rapid growth of calcium carbonate, enhances the reactivity and reaction time between the surfactant and the nano-calcium carbonate particles, and improves the dispersion and surface modification degree of the calcium carbonate nanoparticles.

The invention provides a method for synthesizing high-valued amorphous calcium carbonate through carbon sequestration of carbide slag, and belongs to the technical field of carbon sequestration and high-valued utilization of industrial solid waste resources. The method comprises the following steps: carrying out active calcium extraction reaction on a dried and ball-milled carbide slag aqueous solution through ammonium chloride, stirring and filtering to obtain a calcium-containing solution; the method comprises the following steps: adding a certain amount of absolute ethyl alcohol and magnesium chloride into a calcium-containing solution, fully stirring, adjusting the pH value to a certain value, and introducing CO2 gas for mineralization reaction to obtain a turbid liquid containing calcium carbonate precipitate; and carrying out centrifugal separation, alcohol washing and drying on the turbid liquid to obtain powder calcium carbonate. According to the method disclosed by the invention, the calcium carbide slag active calcium liquid is extracted by adopting ammonium chloride, and absolute ethyl alcohol-magnesium chloride is added to precisely regulate and control the reaction steps of CO2 and the extracted calcium liquid, so that the CO2 is efficiently fixed, and meanwhile, mineralization is performed to obtain a mixed crystal type amorphous nano calcium carbonate product. According to the technology, double targets of synthesizing high-valued calcium carbonate through carbide slag carbon sequestration are achieved, and an innovative technical path is invented for current solid waste resource utilization.

The invention belongs to the technical field of carbon dioxide sequestration, and particularly discloses a method for sequestration of CO2 in a mine goaf through mineralization grouting, which comprises the following steps of: filling and mining by adopting a short-wall working surface strip to form a closed goaf; water swelling rubber slurry is injected into the filling body, and a sealing layer with the thickness larger than or equal to 0.5 m is formed after swelling; an impermeable layer is formed through a top plate reconstruction technology; cO2 is injected into the closed goaf, a calcium ion release source reacts with CO2 to generate calcium carbonate, and chemical sequestration is achieved. The coal mine goaf CO2 sealing device can achieve coal mine goaf CO2 sealing, CO2 leakage is effectively prevented, and the environment and safety are guaranteed.

The invention relates to a preparation method of high-purity cesium carbonate, which comprises the following steps: by taking pollucite as a raw material, leaching with sulfuric acid, cooling and crystallizing to obtain crude cesium alum, recrystallizing to obtain high-purity cesium alum, adding at least one of cesium salt or cesium solution of which the cesium molar weight is greater than the aluminum molar weight in the production process in the recrystallization process, removing aluminum, converting, purifying and removing impurities, thereby obtaining the high-purity cesium carbonate. And carrying out evaporation concentration and carbonization crystallization to obtain high-purity cesium bicarbonate, and finally drying and decomposing to obtain a high-purity cesium carbonate product. Compared with a conventional method for preparing cesium carbonate through extracting cesium from pollucite and a conventional method for preparing high-purity cesium carbonate through an extraction method, the method has the advantages that the product purity is greatly improved, the content of cesium carbonate is larger than or equal to 99.999% wt in terms of Cs2CO3, the total amount of impurities including Li, Na, K, Rb, Ca, Mg, Al, Fe, SiO2 and heavy metal (in terms of Pb) is smaller than or equal to 0.001% wt, and especially the content of the same-main-group impurity Rb is smaller than or equal to 0.0001% wt.

The invention discloses a preparation method of micron-sized calcium carbonate based on a composite dispersant system. The preparation method comprises the following steps: S1, mixing carbide slag with an ammonium chloride solution for calcium extraction reaction to obtain a calcium chloride-ammonia-ammonium chloride solution; s2, adding a solution of a composite additive into the solution obtained in S1, and introducing CO2-containing power plant flue gas for carbonization until the pH value is 7.5-8.5; and S3, carrying out solid-liquid separation, washing and drying on the carbonized product obtained in S2 to obtain the monodisperse micron-sized calcium carbonate. According to the method disclosed by the invention, mono-dispersed and single-crystal micron-sized calcium carbonate with uniform particle size distribution can be obtained; the composite additive is added into a calcium chloride-ammonia-ammonium chloride-power plant flue gas carbonization system, so that the preparation of monodisperse and single crystal type micron-sized calcium carbonate can be realized.

The invention relates to a method for preparing superfine calcium carbonate powder by using a carbide slag ammonium salt circulation method, and belongs to the field of inorganic material preparation. The calcium carbide slag is used as a raw material, calcium in the calcium carbide slag is leached out through an ammonium salt solution, and a refined calcium salt solution is obtained after impurity removal and refining. Then, the nucleation particles are subjected to carbonization reaction with carbonizers of different systems in a stator-rotor reactor, and the particle size, dispersity and morphology of the nucleation particles are effectively controlled by adjusting the rotating speed, the recycle ratio and the temperature in the reaction process to strengthen the gas-liquid mass transfer and micro-mixing process. And after the reaction is finished, filtering, washing and drying to obtain the superfine calcium carbonate powder. The mother liquor can be recycled. By adopting the stator-rotor reactor, the reaction efficiency is greatly improved, the reaction time is shortened, and the prepared calcium carbonate powder has the characteristics of small particle size and good dispersity. The method realizes resource utilization of industrial waste residues and emission reduction of carbon dioxide, has the advantages of low cost, no pollution and environmental protection, and is suitable for industrial production.

The invention provides a method for preparing vaterite type nanoscale calcium carbonate with ardealite as a raw material and application of the method, and relates to the technical field of inorganic nano-material preparation.The method comprises the following steps that firstly, efficient dissociation of calcium ions in the ardealite is achieved through a phase transfer method, then digestion treatment is conducted on a leaching solution, and the leaching solution is obtained; a crystal morphology regulating agent is further introduced to construct a mineralized microenvironment, and then through a carbon dioxide carbonization reaction, vaterite type nano-scale calcium carbonate with a specific average particle size (200-400 nm) is prepared. According to the preparation method, natural high polymer materials such as collagen are introduced in the preparation process to serve as green crystal form guiding agents, so that the coordination effect of the natural high polymer materials and calcium ions can be utilized, the crystal morphology can be effectively regulated and controlled, and the biocompatibility of the nano material is improved; and the application possibility of calcium carbonate in the biomedical fields of drug carriers, bone repair materials and the like is expanded.

The invention provides a device and method for directly mineralizing carbon dioxide in air by using industrial solid waste carbide slag, the device comprises a raw material closed-loop crushing and weighing system and a main reactor system, the raw material closed-loop crushing and weighing system is used for controlling the fineness of crushed carbide slag to be that the mass of particles with the particle size smaller than 2 mm accounts for 90%-100% of the total mass; the main reactor system comprises a bubbling bed mineralization reactor, a riser mineralization reactor and a gas-solid parallel flow downer mineralization reactor which are connected in sequence. The raw material crushing and screening system controls the granularity of the carbide slag to be-2mm, the content of the carbide slag is 90-100 wt%, then the carbide slag is fed into the main reactor system, the main reactor system works cooperatively, the bubbling bed completes pre-carbonation of alkaline substances on the surface layer and the shallow layer of the carbide slag, and the riser and downer coupling system further carbonates an intermediate product. And finally, efficient mineralization of the carbide slag is achieved, the mineralization rate is high, the conversion rate is high, the product granularity is stable, system adjustment is intelligent, CO2 emission can be effectively reduced, and resource utilization of industrial solid waste is promoted.

The subject process relates generally to producing an aqueous solution through a simple but highly effective chemical reaction. The aqueous solution is composed of a blended solution with water and an added solubilizer for the chemical reaction. The results produce an ionic solid and an alkaline liquid solution which are useful commercial products, and various applications including but not limited to use as a CO2 capture solvent.

A system for softening high-salinity water via self-induced calcium bicarbonate crystallization in a fluidized bed, including a fluidized bed-based crystallization-softening reaction unit, a water feeding unit, a dosing unit and a regulation unit. The fluidized bed-based crystallization-softening reaction unit is configured to induce a crystallization reaction to soften high-salinity water. The water feeding unit is configured to supply high-salinity water to the fluidized bed-based crystallization-softening reaction unit. The dosing unit is configured to supply a pH regulating agent to the fluidized bed-based crystallization-softening reaction unit. The regulation unit is configured to perform reflux replenishment for the fluidized bed-based crystallization-softening reaction unit and recover escaping crystals. A high-salinity water softening method using such system is also provided.

The invention provides a method for preparing monodisperse nano calcium carbonate from calcium-containing industrial solid waste. The method for preparing the monodisperse nano calcium carbonate by using the calcium-containing industrial solid waste comprises the following steps: S1, mixing the calcium-containing solid waste and an ammonium salt solution, reacting, and filtering to obtain a calcium-containing filtrate; s2, mixing the calcium-containing filtrate, CO2-containing gas and a crystal form control agent, reacting, and filtering to obtain nano calcium carbonate; and S3, mixing the nano calcium carbonate with the aqueous solution containing the surfactant, reacting, centrifuging, washing and drying to obtain the monodisperse nano calcium carbonate. According to the method, the leaching rate of calcium in the calcium-containing solid waste is increased, explosive nucleation and rapid growth of calcium carbonate are achieved, the reaction capacity and reaction timeliness between a surfactant and nano calcium carbonate particles are enhanced, and the dispersion degree and the surface modification degree of the calcium carbonate nano particles are improved.

The invention relates to a comprehensive utilization major cycle process in cooperative treatment of industrial flue gas pollutants, which comprises the following steps: removing SO2 and NOx in flue gas by adopting an adsorption method, and desorbing SO2 and NOx by adopting a water solution method to generate sulfuric acid and nitric acid; sulfuric acid reacts with sodium chloride to produce hydrochloric acid; sulfuric acid, nitric acid and hydrochloric acid are combined into a composite acid solvent, the solvent dissolves aluminum oxide in the fly ash to be converted into polybasic acid aluminum, the polybasic acid aluminum is subjected to ammonification decomposition into aluminum hydroxide and composite acid ammonium, the composite acid ammonium reacts with calcium carbonate to generate NH3, CO2 and polybasic acid calcium, and the polybasic acid calcium reacts with sodium sulfate to generate nano calcium sulfate; the method comprises the following steps: reacting silicon dioxide with sodium hydroxide to generate sodium silicate, reacting sodium silicate with sodium bicarbonate to generate silicic acid and sodium carbonate, reacting sodium carbonate with calcium hydroxide to generate calcium carbonate and sodium hydroxide, and mixing multi-element metal oxide separated from aluminum and silicon extraction with silicon dioxide and aluminum hydroxide which are separated and carried to prepare a multi-element cation molecular sieve; and comprehensive utilization and large circulation of the flue gas pollutants are realized through the synergistic effect of the pollutants.

The present application provides a method for extracting lithium from salt lakes. The method comprises the following steps: (1) subjecting concentrated brine to ammonia vapor magnesium precipitation treatment to obtain a magnesium-removed filtrate and filter residue; (2) mixing the filter residue with hydrobromic acid, adjusting the pH to precipitate boric acid, and performing solid-liquid separation to obtain a filtrate and boric acid; (3) evaporating and concentrating the filtrate obtained in step (2), performing aeration treatment after drying treatment, and performing water immersion separation treatment to obtain a lithium-rich solution and magnesium oxide; (4) mixing the lithium-rich solution and lithium carbonate to perform a solid-phase transformation reaction, and filtering to obtain a purified lithium salt solution and calcium carbonate. The method of the present application can separate boron, magnesium, and calcium-lithium in one step, and further calcium removal can separate calcium and lithium, which is beneficial to obtaining high-purity lithium carbonate and reducing lithium loss caused by the adsorption of lithium by magnesium hydroxide colloid.

A method and equipment for recycling alumina red mud. First, the alumina red mud is added to a mixed acid of hydrochloric acid and sulfuric acid for reaction to dissolve metals such as iron, aluminum, calcium, sodium, and a small amount of zinc, copper, magnesium, etc., and the solid silicon dioxide is left to be separated as building materials or glass raw materials; after the solution is collected, ammonium bicarbonate is added to obtain aluminum, calcium, and some metal precipitates and separated. Iron and sodium remain in the solution and continue to react with sodium hydroxide to obtain iron hydroxide precipitate and separate out sodium salts. After evaporation of the concentrated solution, iron oxide is obtained as a raw material for steel production; the aluminum, calcium, and other metal precipitates are added to sulfuric acid with a concentration of 90-98% for reaction. After all are dissolved, the solution is subjected to membrane separation and then carbonates are added to obtain calcium carbonate precipitate as a raw material for cement production; after evaporation of the concentrated solution, high-purity alumina is obtained and sent to an aluminum processing plant to produce pure aluminum or aluminum alloy products; the separated sodium salt solution is evaporated to be used as industrial and agricultural salt; the acid mist and harmful gases in the reactor process are treated by an absorption tower and then discharged. The present invention can make full use of the iron oxide, alumina, and effective components of alumina red mud, solves the problem of environmental pollution caused by the large amount of piled-up alumina red mud at present, has a low cost, and is suitable for the current alumina production plants.

The invention provides a ternary positive electrode material and a preparation method thereof, and the method comprises the following steps: obtaining a tungsten and boron double-doped ternary positive electrode material through a mixed sintering method, introducing a Co element to react with free lithium during secondary sintering, and generating an ionic conductive compound LiCoO2 on the surface of the ternary material, and finally, coating a layer of nano CaCO3 on the ternary material of which the surface is coated with LiCoO2, so as to obtain the ternary positive electrode material with a doped coating structure. The ternary positive electrode material prepared by the invention has excellent conductivity and can effectively inhibit the growth of lithium dendrites, and meanwhile, the structural stability of the material can be enhanced through doping modification, so that the low-temperature power, high-temperature storage and cycle performance of the ternary lithium ion battery are improved.

The following relates generally to systems and methods for using chemical reactions, electrodialysis of cation-containing brines, such as NaCl and biogenic carbon dioxide sources, such as seawater, to create net-zero cation carbonates, such as soda ash, and / or carbon dioxide gas with an acid such as HC1 as byproduct for sales and / or further use.

The invention relates to the technical field of calcium carbonate preparation, in particular to a method for efficiently removing impurities from steel slag calcium extraction filtrate and preparing light calcium carbonate, which comprises the following steps: S1, mixing steel slag solid waste with an ammonium salt solution, reacting, and filtering to obtain calcium extraction filtrate; s2, adding a pH regulator into the calcium extraction filtrate, introducing an oxidizing agent for reaction, filtering to obtain high-purity calcium-containing filtrate and a slag phase, and drying to obtain a multi-element composite hydroxide; and S3, mixing the high-purity calcium-containing filtrate, the CO2-containing gas and a crystal form control agent, reacting, and filtering to obtain the high-purity light calcium carbonate. The method is easy to operate, the process of preparing calcium carbonate through calcium extraction and mineralization of the steel slag is greatly shortened, impurity components are not introduced in the impurity removal process of the calcium extraction filtrate, and the problems of safety, equipment, poor pH stability, step-by-step oxidation and impurity removal, difficult filtration, low impurity removal efficiency and the like in the impurity removal process of an ammonia method are solved. The obtained high-purity light calcium carbonate is low in cost and low in energy consumption.