57results about "Alkali metal hydroxides" patented technology

This invention relates to the fields of high-purity sodium preparation and safe disposal of sodium-calcium slag, and discloses a method and apparatus for preparing high-purity sodium and safely disposing of sodium-calcium slag using a gravity separation-controlled combustion-alkali leaching process. The method includes the following steps: (1) gravity separation of liquid sodium slag to obtain pure sodium and high-calcium sodium slag; (2) calcination of the high-calcium sodium slag to obtain calcined slag; (3) leaching of the calcined slag with an alkaline solution to obtain sodium hydroxide solution and calcium hydroxide. The method and apparatus provided by this invention have advantages such as high efficiency in separating sodium and calcium, saving separation time, safe and controllable production process, and continuous production process. It provides a safe and efficient method for the preparation of high-purity sodium and safely disposes of the new sodium-calcium slag generated by this method, realizing the continuous preparation of high-purity sodium and the safe recycling of new sodium-calcium slag.

The disclosure provides a method for recycling waste cathode by soluble calcium salt. The method for recycling waste cathode by soluble calcium salt comprises the following steps: S1, screening waste cathode; S2, mixing soluble calcium salt with water to prepare first slurry; S3, mixing first powder and the first slurry, and performing flotation under the assistance of ultrasonic, separating upper flotation foam, and then filtering to obtain first filtrate and first filter residue; S4, performing acid leaching on the first filter residue, and filtering to obtain second filtrate and second filter residue, wherein the second filter residue is calcium fluoride; S5, evaporating the second filtrate to obtain aluminum salt; and S6, evaporating and drying the first filtrate to obtain an alkali mainly containing sodium hydroxide.

Provided is a method for concentrating a sodium hydroxide aqueous solution including: in a stepwise concentration process of sodium hydroxide aqueous solution, including a concentration part in which a plurality of evaporators from a first evaporator to a nth evaporator are connected in series, adding a sodium hydroxide aqueous solution to the first evaporator and then performing evaporation to obtain a first sodium hydroxide concentrate, and recovering steam evaporated from the sodium hydroxide aqueous solution; and adding the first sodium hydroxide concentrate to an evaporator at a subsequent stage, and adding the steam recovered from the first evaporator to a mechanical vapor recompression device to perform compression, wherein the nth evaporator uses the compressed steam as a heat source.

This application relates to the field of organic synthesis technology, specifically disclosing a process for preparing tert-butyl vinyl ether. The raw materials include solid tert-butanol, acetylene, tetrahydrofuran solvent, and potassium hydroxide catalyst, supplemented with auxiliary materials such as type 3A molecular sieves and activated alumina adsorbents. The preparation method involves: after dehydration and purification of the raw materials, the materials are introduced into a reaction vessel; temperature and pressure are controlled, and the reaction endpoint is monitored using an infrared spectrometer; byproducts are quenched and acetylene is recovered; the process involves multi-stage condensation, water washing to remove impurities, distillation separation, and solvent purification and recycling, with simultaneous integration of waste heat recovery and continuous material feeding. The tert-butyl vinyl ether prepared by this process, as an important fine chemical intermediate, can be used in coatings, adhesives, and polymer material modification, possessing advantages such as high purity and good stability. The preparation method achieves efficient utilization of materials and energy through multi-stage synergistic linkage, combining the advantages of green environmental protection, continuous and stable operation, and high resource utilization.

The present invention provides a method (700) and apparatus for producing liquid sodium from sodium hydroxide other than by electrolysis. The method comprises reacting solid-phase sodium hydroxide in an anoxic environment with an amount of liquid sodium in excess of the stoichiometric amount thereof required to produce sodium oxide and hydrogen gas, capturing at least some of the hydrogen gas, phase-separating at least some of the sodium oxide from the excess amount of liquid sodium, thermally decomposing at least some of the sodium oxide under vacuum to produce sodium vapour and oxygen gas, condensing at least some of the sodium vapour to produce liquid sodium, and recycling some of the liquid sodium thus produced to the reaction with the solid-phase sodium hydroxide. Subject to real-world losses and inefficiencies, the amount of liquid sodium produced by condensing the sodium vapour is double the stoichiometric amount thereof required to react with the sodium hydroxide, so that half of it may be recycled back to this reaction, whilst recovering the same amount of sodium from the sodium hydroxide. This chemical cycle therefore analyses the sodium hydroxide into its constituent elements without consuming the liquid sodium with which the sodium hydroxide reacts and without using electrolysis. It therefore effectively provides a chemical alternative to the electrolytic production of liquid sodium via the Castner process, whilst also consuming less energy than the Castner process because of the latter's inherent inefficiency. The corresponding apparatus comprises a gas-tight reaction vessel for reacting the sodium hydroxide with the liquid sodium in an anoxic environment and capturing the hydrogen gas, a solid-liquid sodium phase separator for separating the sodium oxide from the liquid sodium, a vacuum chamber for thermally decomposing the sodium oxide into sodium vapour and oxygen, a sodium condenser for condensing the sodium vapour, and a liquid sodium return path for returning liquid sodium from the sodium condenser to the gas-tight reaction vessel. [Fig. 2]

Disclosed in the present invention is a system for online conversion of a sodium source into heat energy and hydrogen. A pipe orifice of a sodium injection pipe is arranged in the upper end of a reactor, a sodium reaction baffle is arranged below the pipe orifice, and a sodium hydroxide solution channel is arranged on the sodium reaction baffle, or a sodium hydroxide solution channel is arranged between the sodium reaction baffle and a side wall of the reactor. The speed of input water vapor is controlled, so as to maintain the concentration of the water vapor in the reactor within a relatively low range, and the highest temperature in the reactor is controlled to be less than 300ºC by adjusting a sodium injection one-way valve or / and adjusting a water vapor injection one-way valve or / and adjusting the heat exchange amount of a condenser, such that sodium combustion caused by an overly-high temperature is avoided, and corrosion to a device caused by high-temperature substances is effectively relieved. The arranged sodium reaction baffle can enable a sodium hydroxide solution coating layer having a high density and a low viscosity to be separated from sodium, such that the surface of sodium is exposed, thereby realizing rapid oxidation of sodium and low-concentration water vapor and maintaining a relatively high level of efficiency in terms of productivity.

The invention discloses a bipolar membrane electrodialysis-based carbonate brine treatment method and device, carbonate brine is added into a prepared low-concentration sodium metaaluminate solution through a chemical precipitation tank for precipitation reaction, suspended solids are removed through a filter, organic matters are removed through an activated carbon adsorption tower, and finally a refined solution is obtained through an ion exchange system; the refined liquid is introduced into a treatment device salt chamber, the voltage is controlled to be 1.5-2.5 V / membrane pair, and circular treatment is performed; deionized water is supplemented to the alkali chamber and the acid chamber respectively, high-purity NaOH is obtained in the alkali chamber, and high-purity carbon dioxide is obtained in the acid chamber. According to the present invention, the efficient separation treatment of the carbonate brine is achieved, the impurities can be effectively removed, the high-purity NaOH and the high-purity carbon dioxide are obtained, the treatment energy consumption is low, the cost is controllable, and the high-value resource utilization of the carbonate brine is achieved.

A method for recovering an active metal of a lithium secondary battery according to an embodiment of the present application whereby a used lithium-containing mixture is prepared, and the used lithium-containing mixture is treated with a hydrogen reduction to prepare a preliminary precursor mixture. The preliminary precursor mixture is washed with water to generate a lithium precursor including lithium hydroxide. Lithium hydroxide can be obtained by the washing treatment with high purity.

A process is provided for capturing and transporting carbon dioxide in a solid or liquid mixture. In this process, a liquid base is added to carbon dioxide to produce a carbonate, the carbonate is then stored or transported to a second facility where an acid is added to the carbonate to release carbon dioxide. The carbon dioxide can then be used as needed. The liquid base or the acid may be mined, collected from an industrial waste stream (fly ash), or produced by a chemical or electrochemical process including electrolysis, electrodialysis, or salt splitting.

The invention provides a preparation method of photovoltaic potassium hydroxide, and relates to the technical field of potassium preparation. The method comprises the following steps: carrying out vacuum gradient crystallization on a KOH raw material to realize crude purification, carrying out centrifugal separation on wet crystals generated after crude purification, dissolving, carrying out three-stage counter-current extraction to obtain photovoltaic-grade KOH, extracting mother liquor generated after crude purification, and circularly carrying out vacuum gradient crystallization; dissolving the wet crystals in ultrapure water to prepare a KOH solution, filtering the KOH solution, enabling the KOH solution and an extracting agent to enter a three-stage counter-current extraction tower for three-stage counter-current extraction, carrying out nanofiltration and ultrafiltration on an output raffinate phase to obtain a photovoltaic-grade KOH product, and regenerating an output loaded organic phase to realize recycling; a microwave generating device is arranged on the three-stage counter-current extraction tower and is used for applying pulse microwaves to the mixing area in the tower. The sodium removal rate is increased, the solvent consumption is reduced, and the generation of hazardous wastes is reduced.

The application belongs to the field of electronic grade material preparation. An electronic grade potassium hydroxide and a preparation method of an electronic grade potassium hydroxide solution are provided. The preparation method of the electronic grade potassium hydroxide solution comprises the following steps: S1. loading the crystalline and purified potassium hydroxide crystals into an alkali corrosion resistant container to form a crystal layer, the thickness of the crystal layer is L cm; S2. applying a periodically changed negative pressure at the bottom of the crystal layer; S3. continuously adding a washing liquid A at the top of the crystal layer, and collecting a daily use grade potassium hydroxide solution at the bottom of the crystal layer; when the impurity content of the solution at the outlet of the bottom of the crystal layer in step S3 is less than or equal to a set value, step S4 is performed; S4. continuously adding a washing liquid B at the top of the crystal layer, and collecting an electronic grade potassium hydroxide solution at the outlet of the bottom of the crystal layer; S5. when the thickness of the crystal layer is 1 / 4L-1 / 2, continuously adding a washing liquid C at the top of the crystal layer, and collecting a material liquid C at the bottom of the crystal layer. The method can produce electronic grade potassium hydroxide and electronic grade potassium hydroxide solution with stable quality and high yield.

The application discloses a method for comprehensively treating red mud and integrating with an alumina production process to realize step-by-step energy utilization, and belongs to the technical field of metallurgy and resource recycling. The method specifically comprises the following steps: oxygen, water vapor, coal powder and red mud powder are sprayed into a flash smelting furnace from a burner at the top of a coal gasification flash smelting furnace, high-temperature heat and high-reducing gas generated by coal gasification are utilized to directly smelt and reduce Fe2O3 in the red mud to produce molten iron, and after the red mud and the coal powder liquid slag are tempered, rock wool or other fiberized materials are directly produced, sodium oxide in the red mud is converted into sodium hydroxide for recycling and reuse; after smelting is completed, high-temperature coal gas waste heat is recovered to produce steam for use in an evaporation section of an alumina production process, coal gas is used in a roasting section of the alumina production process, and roasting tail gas is used for red mud drying. The application realizes integration of red mud treatment and the alumina production process and process reengineering, meets the energy needs of two process courses through clean and efficient step-by-step utilization of coal, realizes energy saving and emission reduction, and has no secondary pollution.

The purpose of the present invention is to provide an alkaline subcritical water composition, a water-containing composition, a device, and a container which are capable of inhibiting corrosion of a reaction device and capable of decomposing a polymer and the like. The present disclosure is an alkaline subcritical water composition having a pH of 13.7 or less and a potential of 400 mV or more when a current density exceeds 10 mA / cm2 in an anodic polarization curve in which a steel material is used in a test electrode.

A sea water desalination process and plant wherein intake sea water is delivered to at least one reverse osmosis pass comprising at least one reverse osmosis membrane to produce permeate product water and brine; wherein at least a portion of the brine is delivered to at least one reactor 2 for the removal of carbonates-based chemical in the brine by precipitating calcium carbonate. The calcium carbonate is converted in a regenerator 10 to produce calcium hydroxide and carbon dioxide. This provides for a series of benefits in the overall cost efficiency and sustainability of the process / plant.

The invention relates to a method for recycling white carbon black wastewater, in particular to a process for extracting sodium sulfate from saline water containing organic matters, silicon dioxide and sodium sulfate and converting the sodium sulfate into acid and alkali to be reused in a production process, which comprises the following steps: introducing a solution containing the organic matters, the silicon dioxide and the sodium sulfate into an inorganic membrane device; introducing the permeate of the inorganic membrane device into a reverse osmosis device to obtain a high-concentration sodium sulfate solution; introducing the reverse osmosis concentrated solution into an evaporative crystallization device to obtain anhydrous sodium sulphate; dissolving anhydrous sodium sulphate, and introducing the dissolved anhydrous sodium sulphate into a bipolar membrane device for electrolysis to obtain a sulfuric acid solution and a sodium hydroxide solution; sodium sulfate can be extracted from organic matters, silicon dioxide and sodium sulfate, and the sodium sulfate is converted into acid and alkali.

The invention discloses a closed-loop preparation and recovery method of an alkaline electrolysis water electrode, and belongs to the technical field of electrochemistry. The method comprises the following steps: thermally spraying nickel-aluminum alloy powder on a nickel net substrate to prepare an electrode precursor, and activating with a sodium hydroxide solution to form the porous Raney nickel structure electrode. The method is characterized in that an internal circulation system is constructed, the aluminum-containing waste alkali liquid activated by an electrode and over-spraying alloy powder subjected to thermal spraying are combined for treatment, and aluminum is selectively leached; carbon dioxide is introduced into the aluminum-rich alkali liquor for carbonization decomposition, and a high-purity aluminum hydroxide product is separated out; carrying out causticization reaction on the carbonized sodium carbonate-containing mother liquor by using calcium oxide to regenerate a sodium hydroxide solution and a calcium carbonate byproduct; and finely adjusting the regenerated alkali liquor, returning to electrode production, and treating the nickel-rich solid to obtain regenerated nickel powder. According to the method, electrode production and material circulation are deeply coupled, near-zero emission closed loop of sodium, nickel, aluminum and calcium elements is achieved, and the aluminum resource product value and recycling economy are improved through the process of first carbonization and then causticization.

The present application relates to a method for extracting lithium from a lithium-containing material. The lithium extraction method according to implementations of the present application can extract lithium from a lithium-containing material through a single process rather than through a conventional hydrometallurgical process.

The invention belongs to the technical field of asbestos tailing utilization, and particularly discloses an asbestos tailing full-resource utilization process. The method provided by the invention comprises the following steps: crushing and sieving asbestos tailings, adding a sulfating roasting reagent and ammonium bisulfate to obtain a mixed material, and roasting the mixed material in a fluidized bed; after heat preservation treatment, water is added for a leaching reaction, and leaching residues and filtrate are obtained through solid-liquid separation; adjusting the pH value of the filtrate to obtain a mixed precipitate of ferric hydroxide and nickel hydroxide and a sulfate solution, performing evaporative crystallization on the sulfate solution, and performing roasting treatment to obtain a mixed oxide; and adding aluminum powder into the mixed oxide, and carrying out aluminothermic reduction reaction to obtain the magnesium ingot. According to the method, high-valued utilization of various elements in the asbestos tailings can be achieved, circular economy and closed-loop utilization can also be achieved, and the economic effect of enterprises is improved.

An improved manufacturing process for lithium hydroxide monohydrate suitable for battery applications is provided. Preferably, potassium hydroxide (KOH) is added to an aqueous solution of lithium sulfate (Li₂SO₄), and the resulting aqueous solution is adjusted to a temperature in the range of 0 to 25°C. After quantitative removal of the K₂SO₄, LiOH can be crystallized in high yield and purity.

Methods and systems for production of lithium hydroxide and lithium carbonate are described. One or more embodiments of the method include producing lithium hydroxide from potassium chloride, lithium chloride, and water. One or more embodiments of the method include producing lithium carbonate from potassium chloride, lithium chloride, water, and a carbon dioxide source. One or more embodiments of the method include producing lithium carbonate from sodium chloride, lithium chloride, water, and a carbon dioxide source.

The invention discloses a device and a method for on-line conversion of a sodium source into high-temperature heat energy, a reactor is filled with hydrogen before reaction, liquid sodium and water vapor are injected, the water vapor and the liquid sodium are in contact and then are subjected to combustion reaction to generate hydrogen and sodium hydroxide, then oxygen is introduced into the bottom of the reactor, and the oxygen is combusted in the hydrogen to generate sodium hydroxide. And sodium is completely eliminated through combustion reaction. The temperature of hydrogen and water vapor high-temperature mixed gas generated by combustion is lower than 70 DEG C after passing through the heat exchanger, water vapor is condensed into water and flows back to the bottom of the reactor, hydrogen is discharged from a hydrogen collecting pipe through a pressure reducing valve, and a sodium hydroxide solution is discharged from the bottom of the reactor. Potential safety hazards such as explosion caused by sodium-water reaction are avoided, high-temperature heat energy of 500 DEG C or above is formed, and efficient energy conversion is achieved.

A method for concentrating an aqueous sodium hydroxide solution is provided, comprising: in a stepwise concentration process of an aqueous sodium hydroxide solution including a concentration section comprising a first evaporator to an nth evaporator connected in series, adding the aqueous sodium hydroxide solution to the first evaporator, then evaporating it to obtain a first sodium hydroxide concentrate, and recovering the vapor evaporated from the aqueous sodium hydroxide solution; and adding the first sodium hydroxide concentrate to a subsequent evaporator, and adding the vapor recovered from the first evaporator to a mechanical vapor recompression device for compression, wherein the nth evaporator uses the compressed vapor as a heat source.

A self-sustainable process and system for treating water wherein at least a portion of the water is fed through a reactor for the removal of carbonates-based chemical by precipitation and at least some of the calcium carbonate precipitant is regenerated to a calcium-based chemical and carbon dioxide which is at least partially utilized to remineralize said fluids in a post-treatment process.

The present application relates to a kind of recycling methods of aluminum electrolysis spent cathode, comprising the following steps: S1, spent cathode is crushed to obtain first powder;S2, first powder is added with prefabricated reagent, so that first powder and prefabricated reagent are mixed to obtain powder mixture.S3, powder mixture is calcined to obtain calcined product.S4, calcined product is crushed to obtain second powder;S5, second powder is added with water to leach and filter, obtain first filtrate and first residue;S6, first residue is separated from carbon powder in first residue using ultrasonic flotation device.By high-temperature calcination, the prefabricated reagent in molten state can more fully react with the powder of spent electrolyte, so that the purity of recycled carbon is higher.Moreover, the gas generated is ammonia, achieving truly green recycling of spent cathode.It can be better applied in industrialization.

Integrated processes and systems for the co-production of titanium dioxide and caustic soda. A chlor-alkali process is integrated with a chloride process of titanium dioxide production to produce both caustic soda and titanium dioxide. A chlor-alkali unit produces caustic soda, chlorine, and hydrogen. The chlorine produced in the chlor-alkali unit then serves as an input for a titanium dioxide production unit. Some or all of the hydrogen is combusted to generate the heat required for the titanium dioxide production unit, and / or used in other processes, such as a reducing agent in the production of direct reduced iron (DRI).

The invention belongs to the field of mineral resource utilization, and particularly relates to a potassium extraction method of potassium-rich slate, which comprises the following steps: carrying out low-temperature hydrothermal treatment on the potassium-rich slate at the temperature T1 to obtain a leaching solution A and a leaching residue A; in a low-temperature hydrothermal system, the weight ratio of Ca to Si is controlled to be 2.2-3.0; the temperature T1 is 120 to 200 DEG C; carrying out high-temperature hydrothermal treatment on the leaching residue A and an alkali activator at the temperature T2 to obtain a leaching solution B and a leaching residue B; wherein in a high-temperature hydrothermal system, the weight ratio of Ca to Si is 2.2 to 3.0; and the temperature T2 is 1.1 to 2 times of the temperature T1. Aiming at the problem of difficulty in potassium extraction of the potassium-rich slate, the invention provides an innovative method which comprises the following steps: firstly, performing low-temperature hydrothermal treatment on raw materials to change the phase and microstructure of the raw materials, and further cooperating with a subsequent high-temperature hydrothermal process, so that the crystal structure of the potassium-rich slate can be effectively destroyed under the synergistic effect of the two, thereby remarkably improving the extraction efficiency and effect of potassium.

The invention relates to a process for extracting high-purity potassium chloride (KCl) from a carnallite ore (KCl.MgCl2.6H2O) associated with halite (NaCl). The process starts with selective dissolution, prioritising KCl and MgCl2, due to the addition of water at room temperature. Two basification steps follow, involving the addition of potassium hydroxide (KOH) to the solution obtained after dissolving the ore. The first addition makes it possible to extract all of the Mg2+ ions in the form of magnesium hydroxide (Mg(OH)2), an upgraded product. The second addition of KOH seeks to convert all the NaCl into potassium chloride (KCl) and sodium hydroxide (NaOH). This second addition of KOH is carried out in excess to promote the formation of the desired products during the following two crystallisation steps. After the chemical transformations of the mineral solution, a concentration step is undertaken to vaporise the water, thereby promoting the crystallisation of the potassium chloride (KCl). A second concentration is followed by cooling in order to form the solid sodium hydroxide (NaOH). The water vapours generated in the two concentration steps are liquefied by cooling to be recycled. The three solid products resulting from the process are dried to remove moisture, thereby complying with market requirements in terms of purity. The proposed process is characterised by zero-waste management and low water consumption, with more than 90% of the water being recycled initially, as well as recycling of the KOH at the end of the process. In addition, it has low energy requirements, since the dissolution of KOH is exothermic. The KCl production of the process is high due to the regeneration of KCl during the chemical transformations, and the process is characterised by its flexibility with respect to different compositions of the starting ore.

The invention relates to the technical field of caustic soda production, in particular to a skid-mounted caustic soda production device which comprises an evaporator and a plurality of uniformly distributed heat exchange pipes fixedly mounted in the evaporator, the bottom of a main connecting pipe is communicated with two hoses, and nozzles are fixedly mounted at the bottoms of the two hoses. The two nozzles are matched with the corresponding heat exchange pipes correspondingly, control valves are arranged at the ends, close to the main connecting pipe, of the two hoses correspondingly, a mounting support is arranged in the evaporator, and a lifting mechanism is arranged above the mounting support. And a second driving mechanism and two rotating mechanisms are arranged at the bottom of the mounting bracket. The automatic washing device has the beneficial effects that the effect that a plurality of heat exchange tubes can be automatically washed in the evaporator is achieved, so that the problem that high-concentration NaOH remained in the evaporator is possibly splashed to the outside to damage an operator and surrounding devices when the operator manually washes the heat exchange tubes is solved.

Methods and systems for hydrogen production from inert sodium salts are described herein. In an example method, steam is generated by a nuclear reactor power plant system. The steam is applied to sodium formate to facilitate one or more thermal and / or hydrothermal decomposition processes, thereby generating hydrogen. In the example method, sodium formate is generated by combining sodium hydroxide generated by an electrolysis process with sodium carbonate and / or sodium bicarbonate generated by a carbon capture process. Embodiments can be used to supply hydrogen storage facilities and / or for energy production.