646 results about "Carbonate" patented technology

The invention discloses a fluoride salt-free nitrate-free cast iron enamel semitransparent glaze as well as a preparation method and application thereof, and belongs to the technical field of enamel. The semitransparent glaze is prepared from quartz, anhydrous borax, sodium carbonate, potassium carbonate, calcium carbonate, potassium feldspar, zinc oxide, lithium carbonate, zirconium silicate, titanium dioxide, aluminum oxide, trisodium phosphate, antimony oxide, magnesium carbonate and barium carbonate according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The semitransparent glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, meanwhile, the product has good porcelain surface, luster and low-temperature firing adaptability, and is suitable for cast iron matrixes, the firing temperature is 740-760 DEG C, and the firing time is 2-3 hours. The method can be used for producing green and environment-friendly enamel products.

A system for capture of atmospheric CO2 includes a reaction reactor having a solid sorbent; and a mineralization reactor downstream from the reaction reactor, the system having three states including in the reaction reactor, a first state of sequestering CO2 from air into the solid sorbent; in the reaction reactor, a second state of releasing the sequestered CO2 from the sorbent by contacting the CO2-enriched sorbent with an exchange fluid having one or more amino acids and forming a CO2-enriched exchange fluid; and in the mineralization reactor, a third state of reacting the sequestered CO2 from the CO2-enriched exchange fluid with an alkaline feedstock to form a carbonate while regenerating the exchange fluid.

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 mineralogy, in particular to a complex iron mineral distinguishing and quantifying method and an iron mineral content analysis method, which innovatively combines chemical dissolution, automatic mineralogy analysis and a micro-area magnetic verification technology to realize distinguishing and quantifying of complex iron minerals. According to the analysis method, a closed and mutual verification analysis system is formed, acid treatment of carbonate, automatic mineralogy analysis of residual minerals, micro-area magnetic verification correction of misjudgment of maghemite, element surface scanning verification of mineralogy total quantification accuracy and a final calculation result, and closed verification of the total iron content of chemical analysis are combined, and therefore the comprehensive performance of the magnetic separation system is improved. The reliability of a final result is ensured and standardized popularization and application are facilitated.

The invention discloses fluoride salt-free and nitrate-free low-temperature matte glaze for steel plate enamel as well as a preparation method and application of the low-temperature matte glaze, and belongs to the technical field of enamel. The matte glaze is prepared from quartz, borax pentahydrate, sodium carbonate, titanium dioxide, magnesium oxide, monopotassium phosphate, calcium carbonate, zinc oxide, magnesium carbonate, lithium carbonate, aluminum oxide and zirconium silicate according to a specific mass ratio. The preparation method comprises the following steps: mixing the raw materials, melting at 1300 + / -10 DEG C in a pure oxygen environment, and quenching after wiredrawing to detect a molten state. The matte glaze completely avoids the use of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are eliminated from the source, the fluorine content of the product is not detected through detection, and the limit value requirements of European Union REACH regulations are met. Zinc oxide and ZnO / TiO2 are added, so that the liquid phase viscosity is reduced, ion diffusion is accelerated, and the opacity (opacification performance) and gloss of the porcelain glaze are enhanced.

The invention discloses a fluoride-salt-free and nitrate-free cast iron enamel zirconium white glaze as well as a preparation method and application thereof, and belongs to the technical field of enamel. The zirconium white glaze is prepared from quartz, borax pentahydrate, magnesium carbonate, potassium carbonate, potassium feldspar, zinc oxide, aluminum hydroxide, calcium carbonate, zirconium silicate, sodium tripolyphosphate and lithium carbonate according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The zirconium white glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, and meanwhile, the zirconium white glaze has good porcelain surface, luster and firing adaptability, is suitable for cast iron matrixes, has the firing temperature of 740-760 DEG C and the firing time of 87-87 hours, and can be widely applied to cast iron substrates. The method can be used for producing green and environment-friendly enamel products.

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 invention relates to the technical field of purification of fine chemical intermediates, in particular to a purification method of a mannitol carbonate sulfate preparation process intermediate, which comprises the following steps: S1, synthesizing diacetone-D-mannitol; s2, preparing an organic solution containing solids; s3, performing deprotection reaction to prepare a solid crude product; s4, removing unreacted solids; s5, extracting and separating by-product solids; and S6, purifying the target product solid and recovering mannitol. Through system separation and multi-component recovery, preparation of a high-purity product and cyclic utilization of unreacted substances, byproducts and raw materials are realized, the yield is remarkably improved, the cost is reduced, and the quality of a final product is guaranteed.

The invention provides coal gangue-based artificial soil as well as a preparation method and application thereof. The preparation method of the coal gangue-based artificial soil comprises the following steps: S1, modifying coal gangue by adopting a solution containing citric acid and ethylenediamine tetraacetic acid to obtain modified coal gangue; s2, preparing the modified coal gangue into artificial soil. According to the invention, the citric acid can dissolve carbonate in the coal gangue, the released carbonate can be combined with heavy metals, and citrate ions and ferric ions can form a complex to destroy the outer layer of ferric oxide of the heavy metals; ethylenediamine tetraacetic acid can permeate into mineral lattices of the coal gangue, lattice bound state heavy metal is released through octahedral Al-O bond breakage, the ethylenediamine tetraacetic acid can capture heavy metal combined with citric acid, a more stable heavy metal complex is formed, the heavy metal complex carries strong negative charges, and the heavy metal complex can be separated from the coal gangue. And electrostatic repulsion can be generated on the surface of the coal gangue with negative electricity, so that the heavy metal removal effect is improved.

The invention discloses a high-aluminum wear-resistant ceramic grinding ball and a preparation method thereof. The grinding ball comprises the following raw materials in percentage by weight: 85%-95% of aluminum oxide, 2%-10% of silicon dioxide, 1%-3% of calcium carbonate, 0.2%-0.5% of magnesium carbonate, 0.03%-0.05% of titanium dioxide, 0.01%-0.03% of sodium oxide and 1%-5% of modified zirconium dioxide. The preparation method of the modified zirconium dioxide comprises the following steps: adding hydrogen peroxide into a mixed solution of soluble cerium salt and soluble zirconium salt to obtain a reaction system; adding the reaction system into an alkaline solution for reaction, and collecting an insoluble substance after the reaction is finished; and calcining the insoluble substance to obtain the modified zirconium dioxide. The ceramic ball is simple in formula, rich in raw materials, low in price and low in production cost, the operation stability of the ceramic ball is improved, and the service life is prolonged.

The present application belongs to the technical field of nanometer material, and discloses a kind of sheet porous nanometer zinc oxide and its preparation method and application.The present application first prepares basic zinc carbonate precursor, then nitrogen is passed into, the pressure of system is >0.4MPa and <0.6MPa, hydrothermal reaction is carried out, and the reaction product is calcined, and sheet porous nanometer zinc oxide is prepared.The sheet porous nanometer zinc oxide prepared by the method of the present application has uniform and regular sheet porous structure, the holes on the sheet are uniform and regular, dense, small in particle size, large in specific surface area, and can be widely applied in the degradation of organic pollutants in photocatalytic system and the field of heavy metal adsorption.The preparation method of the present application can obtain raw materials easily and can be mass-produced.

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

The invention relates to the technical field of water pollution treatment, and discloses a sulfur autotrophic denitrification filler for nitrogen wastewater treatment and a preparation method thereof.The sulfur autotrophic denitrification filler comprises composite particles capable of being degraded step by step, and the composite particles are synergistically limited by chemical compositions and microscopic physical structures; the main alkali source calcium-based carbonate and the sacrificial alkali source magnesium-based oxide establish an interface self-updating mechanism by utilizing the reaction rate difference; physically, a pore structure composed of a reaction chamber and a throat is built in the filler, self-cleaning of an endogenous mass transfer channel is achieved through denitrification product nitrogen, and through internal cooperation of chemical and physical mechanisms, the problems of interface passivation and pore silting self-locking of traditional sulfur-based filler caused by reaction products are solved; the active self-updating and long-term stable operation capabilities of the filler are realized, so that the application potential of a cheap alkali source is released.

The invention belongs to the technical field of synthesis, and particularly relates to a synthesis method of urea [14C]. The synthesis method of the urea [14C] comprises the following steps: (1) reacting carbonate [14C] with ammonia gas to obtain cyanamide salt [14C]; (2) hydrolyzing the cyanamide salt [14C] obtained in the step (1) with concentrated sulfuric acid at the hydrolysis temperature of 35-45 DEG C; and (3) adjusting the pH value of the hydrolysate obtained in the step (2) with ammonia water, concentrating and purifying to obtain urea [14C]. The synthesis method provided by the invention has the advantages of mild conditions, efficient reaction, high product yield (up to 95% or above), high purity (the chemical purity is greater than or equal to 99%) and the like, and is suitable for large-scale preparation of key raw materials of helicobacter pylori diagnostic reagents.

This application discloses a composite mineralization material, its preparation method, and its application, belonging to the technical field of mineralization materials for water purification. The preparation method includes the following steps: (1) Selecting strontium-containing ore, zinc-containing ore, metasilicic acid-containing ore, and carbonate-containing ore from natural ores, crushing the above ores respectively, and calcining them at 600-800℃ for 1-4 hours; (2) Soaking the calcined ores in pure water, then performing carbonation treatment, air-drying, and performing component analysis to screen and obtain the strontium-containing mineralization material, zinc-containing mineralization material, metasilicic acid-containing mineralization material, carbonate-containing mineralization material, and basic material; (3) Crushing the mineralization material and basic material again, mixing them according to the weight ratio to obtain the composite mineralization material. The composite mineralization material prepared by this method can solve the problem of excessive metal elements and organic matter in natural ores, and can achieve stable dissolution of minerals, reduce scaling, and improve the service life of water purification devices.

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 invention discloses a method for improving phosphorite reaction activity and fluorine resource recovery rate. The method mainly aims at medium-low-grade collophanite after flotation, and comprises the following steps: firstly, pretreating phosphorite by using fluosilicic acid to prepare high-concentration phosphorite slurry; carrying out premixing reaction on the phosphoric ore pulp and phosphoric acid, and then carrying out crystallization reaction with sulfuric acid with a certain concentration; a flash cooling and flue gas washing system is arranged in each reaction area, so that escape and recovery of fluorine are enhanced; and after the reaction is finished, filtering and washing to obtain phosphoric acid and phosphogypsum. The phosphorite is pretreated by using low-concentration fluosilicic acid recovered in a phosphoric acid concentration section, the phosphorite pre-decomposition pH is adjusted by using fluosilicic acid, carbonate, silicate and quartz impurities in the phosphorite are preferentially dissolved, and micro-channels are formed on the surfaces of phosphorite particles, so that the subsequent use amounts of phosphoric acid and sulfuric acid are reduced, and the content of aluminum phosphate ions in the product is reduced; the phosphorite acidolysis efficiency is improved. Meanwhile, introduction of fluosilicate accelerates escape of fluorine in phosphorite, and the fluorine yield of the system is increased.

The application discloses a preparation method of a nickel-doped and high-hydrated cobalt-chromium-iron ore monocrystal under high temperature and high pressure, and the method comprises the following steps: preparing a cylindrical cobalt-chromium-iron ore sample by taking solid basic cobalt carbonate powder, solid chromium (III) acetate hydroxide crystal powder, solid nickel stearate, solid oxalic acid powder, solid chromium hydroxide powder, solid nickel hydroxide powder and liquid dilute nitric acid as starting raw materials; preparing water source sheets by taking chromium hydroxide powder and nickel hydroxide powder in a weight ratio of 4:1; placing two water source sheets at two ends of the cylindrical cobalt-chromium-iron ore sample respectively and then putting them into a double-capsule structure sample bin; and obtaining a cobalt-chromium-iron ore monocrystal after high-temperature and high-pressure reaction, so that the blank of the preparation technology of the nickel-doped and high-hydrated cobalt-chromium-iron ore large-grain monocrystal under the current high-temperature and high-pressure condition is solved, and the experimental sample of the nickel-doped and high-hydrated cobalt-chromium-iron ore large-grain monocrystal is obtained.

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.

The invention relates to a method of beneficiation of high-carbonated bauxites to remove carbonates to produce alumina by the Bayer process, said method comprising grinding bauxite in a solution of ethylenediaminetetraacetic acid (EDTA) disodium salt with a concentration of no less than 100 g / dm3, holding the obtained slurry while stirring at a temperature of no less than 70 °C, followed by filtering the obtained slurry to obtain a beneficiated bauxite and solution saturated with calcium salts, the beneficiated bauxite with a reduced carbonate content is fed to alumina recovery and the solution saturated with calcium salts is fed to regeneration of the EDTA disodium salt. The proposed method provides for effective removal of carbonates from bauxites (> 90 %), as well as increases the recovery of market-grade alumina from bauxites.

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 application discloses a kind of polymer oil displacement agent for carbonate fractured-vug type reservoir and preparation method thereof, step 1, with acetone and ethanol mixed solution as solvent, N, N-dimethylpropylene diamine, diethyl ether and perfluorinated nonanoic acid are added into acetone-ethanol mixed solution, after complete reaction, chloropropene is added, continue to react, after reaction is finished, solvent is removed by evaporation, to obtain fluorocarbon cation hydrophobic monomer CF-1;Step 2, white oil, emulsifier Span80 and Tween80 with mass ratio of 35-45:1-3:1-2 are mixed uniformly to obtain oil phase;AM, sodium p-styrenesulfonate and fluorocarbon cation hydrophobic monomer CF-1 are dissolved in deionized water, sodium bisulfite is added, and stirred uniformly to obtain aqueous solution;The aqueous solution is added to the oil phase to obtain a uniform emulsion, ammonium persulfate is added, and the polymer oil displacement agent is obtained by reaction. It has higher temperature resistance and salt resistance, and greatly reduces the adsorption of carbonate reservoir on the oil displacement agent.

To provide a method for evaluating carbon dioxide fixation filler suitable as a technique for evaluating the long-term durability of carbon dioxide fixation filler to be placed in abandoned tunnels of closed and abandoned mines, and to provide an analysis method and analysis program applicable to said evaluation method. [Solution] One aspect of the present invention is a method for analyzing carbon dioxide fixation filler, which is a method for evaluating filler placed in an underground space, in which the filler is a carbon dioxide fixation material containing carbonate produced by reacting a starting material with carbon dioxide, and the method acquires physical quantities indicating the quality of the groundwater present in the target underground space, the temperature and depth of the underground space, the amount of carbonate contained in the filler, the dissolution rate of the filler in groundwater, the specific surface area of ​​the filler, and the ratio of the amount of groundwater inflowing into contact with the filler to the amount of filler, and analyzes changes in the amount of carbon dioxide fixation by the filler over time based on the acquired physical quantities, temperature and depth, amount of substance, dissolution rate, specific surface area, and ratio.

The invention relates to a weighted authigenic acid as well as a preparation method and application thereof. The weighted authigenic acid comprises an acid generating component and a weighting component, the acid generating component comprises an acid generating agent, a product solubilizer, a catalyst and a corrosion inhibitor; the acid generator comprises organic weak acid and a chlorine-containing acid generator; the weighting component comprises weighting salt, a resistance reducing agent and water; the aggravated authigenic acid is high in acid generation efficiency and controllable in acid generation concentration, the concentration of generated H < + > can reach up to 4.95 mol / L, the aggravated authigenic acid has high corrosion inhibition capacity, the corrosion rate is as low as 30 g / (m < 2 >. H) or below, the preparation method is simple, raw materials are easy to obtain, and the aggravated authigenic acid can be used for efficient transformation of ultra-deep high-temperature carbonate reservoirs with the temperature reaching up to 120-200 DEG C.

The invention discloses a magnesium carbonate crystal prepared based on hexamethylenetetramine and a preparation method thereof, and belongs to the technical field of magnesium carbonate materials. The preparation method comprises the following steps: dissolving urea and magnesium chloride, adding hexamethylenetetramine, oscillating in water bath ultrasonic to fully react, then transferring the reaction system into a hydrothermal reaction kettle to perform hydrothermal reaction, and washing and drying a reactant to obtain magnesium carbonate crystals. According to the invention, magnesium chloride and urea are taken as raw materials, hexamethylenetetramine is taken as an additive, the nucleation-growth process is directionally regulated by the hexamethylenetetramine additive, and an optimized reaction process is adopted, so that the magnesium carbonate crystal with high purity, good crystallinity and an excellent pore structure is successfully synthesized; the prepared magnesium carbonate crystal has an optimized porous structure. According to the structure, the mass transfer efficiency is effectively improved, diffusion and transmission of substances in the material are facilitated, and the preparation method is simple and has wide application potential.

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

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.

The invention belongs to the technical field of waste residue recycling, and provides a resourceful treatment method of a lithium-containing material. By means of leaching, metal (Al, K, Na, Cs, Rb, Li, Ca, Mg, Fe, Tl and other heavy metal) in the lithium-containing material can be leached out, and harmlessness of the lithium-containing material is achieved; the brine rich in metal salt is oxidized to remove iron and thallium, so that iron, thallium and other heavy metals in the brine can be fixed and removed in a hydroxide form; cooling crystallization is carried out, so that alkali metal ions and aluminum in the brine can be fixed and removed in the form of aluminum sulfate alum salt; the carbonate precipitation can fix and remove metal ions such as aluminum, calcium and magnesium in the brine in the form of carbonate; magnesium and calcium in the brine can be fixed and removed in the form of calcium-magnesium mud through impurity removal; after evaporation and concentration, recovery of lithium carbonate is realized, and recovery of sodium sulfate is realized through evaporation and crystallization. According to the resourceful treatment method, valuable metal in the lithium-containing material is recycled, and harmless treatment is achieved.

The present disclosure provides a molded magnesium carbonate body including between 90-99.9 wt% magnesium carbonate formed into a plurality of uniform shapes having uniform sizes. Between 80-99.9 wt% of the molded magnesium carbonate body may crushed to a fine powder containing a plurality of particles having an average diameter or longest dimension for the plurality of particles between 0.5-100 µm when the molded magnesium carbonate body is subjected to crushing with a force of 100 N for at least 1 second. The present disclosure also provides a molding process for forming such molded magnesium carbonate bodies by suspending magnesium carbonate particles in an alcohol / water mixture having an alcohol:water ratio between 30:70 and 40:60 to form a uniform slurry, filling a mold having desired dimensions of the molded magnesium carbonate body with the slurry, and drying the slurry to form a solid molded magnesium carbonate body

Provided herein are compositions, methods and systems for precipitating metallic carbonate using cyanobacteria. The precipitated metallic carbonate can be of high purity and / or has a biogenic signature associated with the one or more cyanobacteria.