CN114477230A - Method for separating alkali salt through chemical sublimation-temperature-changing crystallization in Hou's combined alkali preparation - Google Patents
Method for separating alkali salt through chemical sublimation-temperature-changing crystallization in Hou's combined alkali preparation Download PDFInfo
- Publication number
- CN114477230A CN114477230A CN202210145771.4A CN202210145771A CN114477230A CN 114477230 A CN114477230 A CN 114477230A CN 202210145771 A CN202210145771 A CN 202210145771A CN 114477230 A CN114477230 A CN 114477230A
- Authority
- CN
- China
- Prior art keywords
- temperature
- sodium chloride
- crystallization
- tower
- sublimation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
- C01C1/00—Ammonia; Compounds thereof
- C01C1/16—Halides of ammonium
- C01C1/164—Ammonium chloride
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D3/00—Halides of sodium, potassium or alkali metals in general
- C01D3/04—Chlorides
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D3/00—Halides of sodium, potassium or alkali metals in general
- C01D3/14—Purification
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D7/00—Carbonates of sodium, potassium or alkali metals in general
- C01D7/12—Preparation of carbonates from bicarbonates or bicarbonate-containing product
- C01D7/123—Preparation of carbonates from bicarbonates or bicarbonate-containing product by thermal decomposition of solids in the absence of a liquid medium
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to a method for separating alkali salt by chemical sublimation-temperature change crystallization in Hou's combined alkali preparation, in particular to a resource utilization technology for efficiently separating and recycling alkali salt in the Hou's combined alkali preparation process. The saturated sodium chloride aqueous solution is subject to ammoniation and carbonization procedures to obtain a bicarbonate solution, then the sodium carbonate and ammonium chloride are obtained by alkali salt separation in high-temperature calcination, chemical sublimation and desublimation procedures, and the mother liquor is crystallized in a high-temperature and low-temperature zone of zone control and sectional feeding, so that the high-efficiency separation of sodium chloride and ammonium chloride products is realized. The method has the advantages that the conversion per pass of the sodium chloride is improved by more than 90 percent, the total conversion of the sodium chloride exceeds 95 percent, the total conversion of the ammonia is more than 98 percent, the yield of the sodium carbonate is more than 90 percent, the yield of the ammonium chloride is more than 90 percent, the purity of the sodium carbonate is more than 99 percent, the purity of the ammonium chloride is more than 99 percent, the content of impurities is reduced to be less than 50ppm, the circulating material is reduced by more than 80 percent, the material and energy loss is greatly reduced, and the economic benefit is improved.
Description
Technical Field
The invention relates to a process method for separating sodium bicarbonate, sodium chloride and ammonium chloride, in particular to a resource utilization technology for efficiently separating and recycling alkali salt in a Hou's combined alkali preparation process.
Background
In recent years, the production amount of industrial byproduct waste salt is getting larger, and the chemical byproduct waste salt slag contains a large amount of impurity salt and toxic and harmful organic matters, which can cause great damage to the environment by random disposal.
The process for producing the soda ash by taking the sodium chloride as the raw material mainly comprises an ammonia-soda process and a combined-soda process, wherein the ammonia-soda process has the defects of low utilization rate of the raw material sodium chloride (the utilization rate of sodium is about 75 percent and the utilization rate of chlorine is 0 percent), and the waste liquor (containing a large amount of calcium chloride and sodium chloride) for preparing the soda is discharged from a system in a large amount, thereby wasting resources and forming new environmental pollution. The combined alkali method is divided into a cold method and a hot method. The cold-process combined alkali method uses solid sodium chloride as a raw material, and ammonium chloride is obtained by freezing, cooling and salting out separation. The thermal method' recovers ammonium chloride, and obtains the ammonium chloride through evaporation concentration-crystallization separation, the method has large water consumption, large energy consumption and high cost in the evaporation process, and the ammonium chloride solution has strong corrosion to equipment. Both of the above processes have limitations in practical production applications. The high-temperature treatment method is to use waste salt in high-temperature flame burning at a temperature above 800 ℃ and to decompose organic substances contained in the waste salt into gas at a high temperature by using thermal equipment such as a rotary kiln and a fluidized bed furnace, thereby achieving the purpose of removing the organic substances. The method is difficult to solve the engineering problems that salt is melted, looped and caked at high temperature (higher than the melting point of the salt), so that equipment cannot normally run and the like, and is difficult to realize industrialization.
Chinese patent CN101244829A reports that ammonium chloride and sodium chloride are recovered from alkali-making mother liquor through vacuum multi-effect countercurrent evaporation, the energy consumption is high, and the corrosion of the centrifuge caused by the high temperature of multi-effect sodium chloride separation is strong, so that the industrial success of the method is not reported at present.
Patent CN 110372007A reports a device and a method for continuously separating ammonium chloride and sodium chloride, in a mixed salt continuous washer and a multi-stage series continuous separator, ammonium chloride mother liquor is subjected to concentration distillation and cooling crystallization to be continuously separated to obtain sodium chloride and ammonium chloride products. Although the method adopts continuous operation, the operation efficiency is improved, but the problems of low quality of separated products, high energy consumption for concentration and the like exist.
Patent CN 102153113A reports that a product for coproducing sodium carbonate, sodium chloride, sodium sulfate and ammonium chloride is obtained by carrying out double decomposition reaction on mirabilite type brine, ammonia and carbon dioxide serving as raw materials, then carrying out high-temperature deamination, nanofiltration membrane separation and evaporation separation.
CN 112723381A discloses a resource method of mixed salt of ammonium chloride and sodium chloride, which takes mixed solid waste of sodium chloride and ammonium chloride as raw materials, adopts the processes of adding liquid alkali reaction, recovering ammonia gas, concentrating and crystallizing and the like to treat the solid waste, recovers and obtains clean ammonia water solution, and simultaneously obtains sodium chloride solid, thereby realizing the effective separation of the ammonium chloride and the sodium chloride. The process takes solid waste as raw material, has simple operation and low energy consumption, reduces environmental pollution, but has low separation effect, low product purity and quality, low one-pass conversion rate of sodium chloride and NH in sodium chloride products4 +Too much ion remains and the quality is not high.
Patent CN 102260002 discloses a method for treating a mixed solution of sodium chloride and ammonium chloride by microfiltration and nanofiltration. The method realizes the concentration of sodium chloride and ammonium chloride through microfiltration and nanofiltration, and simultaneously generates chlorine, hydrogen and ammonia gas through electrolysis. Although the method can generate clean energy, the nanofiltration membrane and the microfiltration membrane are easy to enrich pollutants, the operation cost is high, and the method is unacceptable for general enterprises.
Disclosure of Invention
In order to overcome the problems in the prior art, the invention provides a method for efficiently separating and recovering alkali salt in the Hou's combined alkali preparation process. The method has the advantages of low raw material cost, simple process, low investment, good production environment, no pollution, good economic benefit, no waste liquid and waste residue generated in the treatment process, capability of completely converting waste salt into useful components, high alkali salt separation effect and high product purity, achieves the aim of maximum resource recycling, provides a feasible process approach for realizing zero discharge of the waste salt, and has good popularization prospect.
In order to realize the purpose of the invention, the adopted technical scheme is as follows: a method for separating alkali salt by chemical sublimation-temperature change crystallization in Hou's combined alkali preparation comprises the following steps:
(1) dissolving sodium chloride with high-purity water by ultrasonic to prepare a supersaturated sodium chloride aqueous solution, conveying the supersaturated sodium chloride aqueous solution into an ammoniation tower through a metering pump, continuously introducing ammonia gas to perform an ammoniation process to absorb the ammoniated sodium chloride aqueous solution into an ammoniated high-salt solution, conveying the ammoniated high-salt solution into a carbonization tower through the metering pump, and continuously introducing carbon dioxide gas to perform a carbonization process to process the ammoniated high-salt solution into a mixed solution containing bicarbonate;
(2) filtering and washing a mixed solution containing bicarbonate to obtain an alkali salt crude product containing sodium bicarbonate and ammonium chloride, decomposing the sodium bicarbonate through a high-temperature calcination process to obtain a sodium carbonate product, and circularly sleeving carbon dioxide tail gas generated in the calcination process into the carbonization tower after washing and pressurizing; carrying out chemical sublimation, desublimation and drying on the ammonium chloride crude product to obtain an ammonium chloride product, collecting ammonia gas released after chemical sublimation, and circularly sleeving the ammonia gas into the ammonification tower;
(3) the filtered mother liquor is an aqueous solution containing ammonium chloride and sodium chloride, a sodium chloride crude product is separated out through a high-temperature crystallization process, and the sodium chloride product is further refined through recrystallization, decoloration and drying processes; then, the crude product of ammonium chloride is separated out through the low-temperature crystallization process, and is further refined into an ammonium chloride product through the recrystallization, decoloration and drying processes, so that the impurity content of sodium chloride in the ammonium chloride product is reduced to be below 50 ppm; collecting ammonia released in the high-temperature crystallization process, circularly using the ammonia in the ammoniation tower, circularly using residual liquid obtained after low-temperature crystallization and recrystallization as an aqueous solution in which sodium chloride and ammonium chloride are dissolved in the carbonizer.
In the ammoniation procedure in the step (1), a saturated sodium chloride aqueous solution flows into an ammoniation tower through a metering pump in a spraying mode through the top of the ammoniation tower and is subjected to countercurrent chemical absorption with ammonia gas blown from the bottom of the tower, the saturated sodium chloride aqueous solution and the ammonia gas are fully mixed and react, the gas is introduced into the tower from the top of the tower from the tangential direction of a waste gas pipeline for circulation treatment, and a spraying device is arranged at the top of the inner side of the tower; controlling the retention time of the saturated sodium chloride aqueous solution in the ammoniation tower through the flow rate, and enabling the ammoniated high-salt solution after chemical absorption to flow out from an overflow port at the top of the tower; the concentration of the saturated sodium chloride aqueous solution is 20-50% (mass concentration), and the molar ratio of ammonia gas to sodium chloride is 1.0-2.0: 1, ammoniation temperature is 30-50 ℃, ammoniation time is 0.5-1 h, and pressure is 0.1-0.5 MPa;
in the carbonization procedure in the step (1), an ammonium high-salt solution is sprayed and flows into the top of a carbonization tower through a metering pump and is subjected to countercurrent chemical absorption with carbon dioxide blown from the bottom of the tower, the ammonium high-salt solution and the carbon dioxide gas are fully mixed and reacted, the gas is introduced into the tower from the top of the tower from the tangential direction of a waste gas pipeline for cyclic treatment, and a spraying device is arranged at the top of the inner side of the tower; controlling the retention time of the high-salt ammoniated solution in the carbonization tower through the flow rate, and enabling the high-salt ammoniated solution after chemical absorption to flow out from an overflow port at the top of the tower; the molar ratio of the carbon dioxide gas to the ammonium high-salt solution is 1.0-1.5: 1, the carbonization temperature is 20-45 ℃, the carbonization time is 0.5-1 h, and the pressure is 0.1-0.5 MPa.
And (3) continuously performing the high-temperature calcination process in the step (2) in a tubular furnace, adjusting the temperature in a hearth through a temperature control system, performing temperature programming (heating rate, 10 ℃/min), continuously feeding the crude alkali salt product containing sodium bicarbonate and ammonium chloride into a cavity of the tubular furnace through mechanical conveying for high-temperature calcination, decomposing the crude sodium bicarbonate product to obtain a sodium carbonate product, wherein the calcination temperature is 200-280 ℃, and the calcination time is 0.5-1 h.
The chemical sublimation and desublimation process of the step (2) is carried out in a sublimation-desublimation separation system, the system is formed by sequentially connecting a raw material buffer tank, a feed pump, a discharge pump, a sublimation kettle, a desublimation kettle, a preheater, a condenser and a circulating pump, wherein inert particles are placed in the sublimation kettle to prevent solid from bumping, and the ammonium chloride crude product is pyrolyzed by the sublimation system to generate NH3And HCl gas, then through a condensing system NH3Reacts rapidly with HCl to regenerate fine NH4And Cl crystals, wherein the sublimation temperature is 340-360 ℃, the desublimation temperature is 65-70 ℃, and the pressure is 0.1-0.5 MPa. The inert particles comprise one or more of glass beads, agate beads, ceramic plates, quartz sand, activated carbon, molecular sieves, fillers (pall rings and Raschig rings), fiber balls and the like; the shape is one or more of spherical, cylindrical, regular hexahedral, tetrahedral, sheet, oval, needle-shaped, strip-shaped, annular, saddle-shaped, grid plate, corrugated plate and the like; the diameter is 1-10 mm.
The high-temperature crystallization process and the low-temperature crystallization process in the step (3) are continuously carried out in a dual-temperature-zone crystallization reactor and a crystallization separator, the temperature change of different zones in the reactor is adjusted through a temperature control system, the high-efficiency separation of sodium chloride and ammonium chloride is carried out in a 'zone control and segmented feeding' mode, the zone temperature (the temperature rise rate of the high-temperature zone, 2 ℃/min and the temperature drop rate of the low-temperature zone, 1 ℃/min) is adjusted through program temperature change, mother liquor containing ammonium chloride and sodium chloride is subjected to high-temperature-zone crystallization and low-temperature-zone crystallization in the crystallization reactor, sodium chloride crystals and ammonium chloride crystals are respectively obtained through the separator, the temperature of the high-temperature crystallization zone is controlled to be 20-30 ℃, and the temperature of the low-temperature crystallization zone is 10-15 ℃.
Further, the ammoniation process conditions in the step (1) are preferably to control the concentration of a saturated aqueous solution of sodium chloride to be 30-40% (mass concentration), the molar ratio of ammonia to sodium chloride is 1.0-1.5: 1, the ammoniation temperature is 30-40 ℃, the ammoniation time is 0.6-0.8 h, and the pressure is 0.2-0.3 MPa; the preferable conditions of the carbonization process are that the molar ratio of the carbon dioxide gas to the ammonium high-salt solution is controlled to be 1.0-1.2: 1, the carbonization temperature is 30-40 ℃, the carbonization time is 0.5-0.6 h, and the pressure is 0.2-0.4 MPa.
Further, the conditions of the high-temperature calcination process in the step (2) are preferably 250-260 ℃ at the calcination temperature for 0.6-0.8 h. The conditions of the chemical sublimation and desublimation processes in the step (2) are preferably 340-350 ℃ of sublimation temperature, 68-70 ℃ of desublimation temperature and 0.2-0.3 MPa of pressure.
Further, the conditions of the high-temperature crystallization process and the low-temperature crystallization process in the step (3) are preferably that the temperature of the high-temperature crystallization zone is controlled to be 20-25 ℃, and the temperature of the low-temperature crystallization zone is 10-12 ℃.
Compared with the prior art, the method for efficiently separating and recovering alkali salt in the Hou's combined alkali preparation process has the following technical advantages: the one-way conversion rate of sodium chloride is improved by more than 90%, the total conversion rate of sodium chloride exceeds 95%, the total conversion rate of ammonia reaches more than 98%, the yield of sodium carbonate is more than 90%, the yield of ammonium chloride is more than 90%, the purity of sodium carbonate is more than 99%, the purity of ammonium chloride is more than 99%, circulating materials are reduced by more than 80%, material and energy loss is greatly reduced, economic benefits are improved, the method is environment-friendly, different solid-phase substances are separated and purified by adopting chemical sublimation, the separation efficiency is high, the product purity is high, three wastes are not generated, the salt product value is remarkably improved, the conversion cost is reduced, the problem of waste salt outlet is solved, and near zero discharge of hazardous wastes is realized.
Drawings
FIG. 1 is a process flow diagram of chemical sublimation-temperature change crystallization separation of alkali salt in Hou's combined alkali preparation according to the present invention.
Detailed Description
The present invention is not limited to the following embodiments, and those skilled in the art can implement the present invention in other embodiments according to the disclosure of the present invention, or make simple changes or modifications according to the design structure and idea of the present invention, and fall into the protection scope of the present invention. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict. The technical solutions in the embodiments of the present invention are further described below with reference to specific embodiments.
Example 1
A method for separating alkali salt by chemical sublimation-temperature change crystallization in Hou's combined alkali preparation comprises the following steps:
(1) dissolving sodium chloride with high-purity water by ultrasonic to prepare a saturated sodium chloride aqueous solution, wherein the mass concentration of the sodium chloride is 20%, continuously introducing ammonia gas into an ammoniation tower to absorb the sodium chloride solution into an ammoniated high-salt solution, wherein the molar ratio of the ammonia gas to the sodium chloride is 1:1, the ammoniation reaction temperature is 30 ℃, the ammoniation time is 0.5h, and the reaction pressure is 0.1 MPa. Conveying the ammonium high-salt solution to a carbonization tower through a metering pump, and continuously introducing carbon dioxide gas to process the ammonium high-salt solution into a mixed solution containing bicarbonate, wherein the molar ratio of carbon dioxide to sodium chloride in the carbonization reaction is 1:1, the carbonization reaction temperature is 20 ℃, the carbonization time is 0.5h, and the reaction pressure is 0.1 MPa;
(2) separating out sodium bicarbonate crystals from the mixed solution containing the bicarbonate at a crystallization temperature of 55 ℃; calcining the sodium bicarbonate crystals at 250 ℃ for 0.6h to obtain a sodium carbonate product, and collecting and recycling generated carbon dioxide gas; and carrying out chemical sublimation, desublimation and drying on the crude ammonium chloride product to obtain an ammonium chloride product, wherein the sublimation temperature is 340 ℃, the desublimation temperature is 68 ℃, the pressure in the process is 0.2MPa, the high-temperature crystallization temperature is 20 ℃, and the low-temperature crystallization temperature is 10 ℃. The content of sodium chloride impurities in the ammonium chloride product is reduced to below 50 ppm. Collecting ammonia released after chemical sublimation, and circularly sleeving the ammonia into the ammonification tower;
the yield of sodium carbonate in the product prepared by the embodiment is 88.2%, the yield of ammonium chloride is 89.2%, the purity of sodium carbonate is 99.5%, the purity of ammonium chloride is 99.2%, and the utilization rate of sodium chloride is 89.2%.
Example 2
A method for separating alkali salt by chemical sublimation-temperature change crystallization in Hou's combined alkali preparation comprises the following steps:
(1) dissolving sodium chloride with high-purity water by ultrasonic to prepare a saturated sodium chloride aqueous solution, wherein the mass concentration of the sodium chloride is 30%, continuously introducing ammonia gas into an ammoniation tower to absorb the sodium chloride into an ammoniated high-salt solution, wherein the molar ratio of the ammonia gas to the sodium chloride is 1.5:1, the ammoniation reaction temperature is 40 ℃, the ammoniation time is 1h, and the reaction pressure is 0.3 MPa. Conveying the ammonium high-salt solution to a carbonization tower through a metering pump, and continuously introducing carbon dioxide gas to process the ammonium high-salt solution into a mixed solution containing bicarbonate, wherein the molar ratio of carbon dioxide to sodium chloride in the carbonization reaction is 1.2:1, the carbonization reaction temperature is 35 ℃, the carbonization time is 0.6h, and the reaction pressure is 0.3 MPa;
(2) separating out sodium bicarbonate crystals from the mixed solution containing the bicarbonate at a crystallization temperature of 65 ℃; calcining the sodium bicarbonate crystals at 250 ℃ for 0.8h to obtain a sodium carbonate product, and collecting and recycling generated carbon dioxide gas; and carrying out chemical sublimation, desublimation and drying on the crude ammonium chloride product to obtain an ammonium chloride product, wherein the sublimation temperature is 350 ℃, the desublimation temperature is 68 ℃, the pressure in the process is 0.3MPa, the high-temperature crystallization temperature is 20 ℃, and the low-temperature crystallization temperature is 12 ℃. The content of sodium chloride impurities in the ammonium chloride product is reduced to below 50 ppm. Collecting ammonia released after chemical sublimation, and circularly sleeving the ammonia into the ammonification tower;
the yield of sodium carbonate in the product prepared by the embodiment is 92.4%, the yield of ammonium chloride is 93.6%, the purity of sodium carbonate is 99.8%, the purity of ammonium chloride is 99.7%, and the utilization rate of sodium chloride is 94.8%.
Example 3
A method for separating alkali salt by chemical sublimation-temperature change crystallization in Hou's combined alkali preparation comprises the following steps:
(1) dissolving sodium chloride with high-purity water by ultrasonic to prepare a saturated sodium chloride aqueous solution, wherein the mass concentration of the sodium chloride is 40%, continuously introducing ammonia gas into an ammoniation tower to absorb the sodium chloride solution into an ammoniated high-salt solution, wherein the molar ratio of the ammonia gas to the sodium chloride is 2:1, the ammoniation reaction temperature is 50 ℃, the ammoniation time is 1h, and the reaction pressure is 0.3 MPa. Conveying the ammonium high-salt solution to a carbonization tower through a metering pump, and continuously introducing carbon dioxide gas to process the ammonium high-salt solution into a mixed solution containing bicarbonate, wherein the molar ratio of carbon dioxide to sodium chloride in the carbonization reaction is 1.5:1, the carbonization reaction temperature is 45 ℃, the carbonization time is 1h, and the reaction pressure is 0.3 MPa;
(2) separating out sodium bicarbonate crystals from the mixed solution containing the bicarbonate at a crystallization temperature of 75 ℃; calcining the sodium bicarbonate crystals at the temperature of 250 ℃ for 1h to obtain a sodium carbonate product, and collecting generated carbon dioxide gas for recycling; and carrying out chemical sublimation, desublimation and drying on the crude ammonium chloride product to obtain an ammonium chloride product, wherein the sublimation temperature is 350 ℃, the desublimation temperature is 70 ℃, the in-process pressure is 0.3MPa, the high-temperature crystallization temperature is 22 ℃, and the low-temperature crystallization temperature is 12 ℃. The content of sodium chloride impurities in the ammonium chloride product is reduced to below 50 ppm. Collecting ammonia released after chemical sublimation, and circularly sleeving the ammonia into the ammoniation tower;
the yield of sodium carbonate in the product prepared by the embodiment is 92.1%, the yield of ammonium chloride is 91.2%, the purity of sodium carbonate is 99.7%, the purity of ammonium chloride is 99.5%, and the utilization rate of sodium chloride is 93.8%.
Example 4
A method for separating alkali salt by chemical sublimation-temperature change crystallization in Hou's combined alkali preparation comprises the following steps:
(1) dissolving sodium chloride with high-purity water by ultrasonic to prepare a saturated sodium chloride aqueous solution, wherein the mass concentration of the sodium chloride is 50%, continuously introducing ammonia gas into an ammoniation tower to absorb the sodium chloride solution into an ammoniated high-salt solution, wherein the molar ratio of the ammonia gas to the sodium chloride is 2:1, the ammoniation reaction temperature is 50 ℃, the ammoniation time is 1h, and the reaction pressure is 0.5 MPa. Conveying the ammonium high-salt solution to a carbonization tower through a metering pump, and continuously introducing carbon dioxide gas to process the ammonium high-salt solution into a mixed solution containing bicarbonate, wherein the molar ratio of carbon dioxide to sodium chloride in a carbonization reaction is 1.2:1, the carbonization reaction temperature is 40 ℃, the carbonization time is 0.6h, and the reaction pressure is 0.4 MPa;
(2) separating out sodium bicarbonate crystals from the mixed solution containing the bicarbonate at a crystallization temperature of 85 ℃; calcining the sodium bicarbonate crystals at 250 ℃ for 0.8h to obtain a sodium carbonate product, and collecting and recycling generated carbon dioxide gas; and carrying out chemical sublimation, desublimation and drying on the crude ammonium chloride product to obtain an ammonium chloride product, wherein the sublimation temperature is 340 ℃, the desublimation temperature is 70 ℃, the in-process pressure is 0.2MPa, the high-temperature crystallization temperature is 25 ℃, and the low-temperature crystallization temperature is 10 ℃. The content of sodium chloride impurities in the ammonium chloride product is reduced to below 50 ppm. Collecting ammonia released after chemical sublimation, and circularly sleeving the ammonia into the ammonification tower;
the yield of sodium carbonate in the product prepared by the embodiment is 92.4%, the yield of ammonium chloride is 91.5%, the purity of sodium carbonate is 99.6%, the purity of ammonium chloride is 99.6%, and the utilization rate of sodium chloride is 94.1%.
Example 5
A method for separating alkali salt by chemical sublimation-temperature change crystallization in Hou's combined alkali preparation comprises the following steps:
(1) dissolving sodium chloride with high-purity water by ultrasonic to prepare a saturated sodium chloride aqueous solution, wherein the mass concentration of the sodium chloride is 40%, continuously introducing ammonia gas into an ammoniation tower to absorb the sodium chloride solution into an ammoniated high-salt solution, wherein the molar ratio of the ammonia gas to the sodium chloride is 2:1, the ammoniation reaction temperature is 40 ℃, the ammoniation time is 1h, and the reaction pressure is 0.2 MPa. Conveying the ammonium high-salt solution to a carbonization tower through a metering pump, and continuously introducing carbon dioxide gas to process the ammonium high-salt solution into a mixed solution containing bicarbonate, wherein the molar ratio of carbon dioxide to sodium chloride in the carbonization reaction is 1.2:1, the carbonization reaction temperature is 40 ℃, the carbonization time is 0.6h, and the reaction pressure is 0.3 MPa;
(2) separating out sodium bicarbonate crystals from the mixed solution containing the bicarbonate at a crystallization temperature of 75 ℃; calcining the sodium bicarbonate crystals at 255 ℃ for 0.6h to obtain a sodium carbonate product, and collecting and recycling generated carbon dioxide gas; and carrying out chemical sublimation, desublimation and drying on the crude ammonium chloride product to obtain an ammonium chloride product, wherein the sublimation temperature is 350 ℃, the desublimation temperature is 68 ℃, the pressure in the process is 0.3MPa, the high-temperature crystallization temperature is 20 ℃, and the low-temperature crystallization temperature is 12 ℃. The content of sodium chloride impurities in the ammonium chloride product is reduced to below 50 ppm. Collecting ammonia released after chemical sublimation, and circularly sleeving the ammonia into the ammonification tower;
the yield of sodium carbonate in the product prepared by the embodiment is 93.4%, the yield of ammonium chloride is 93.5%, the purity of sodium carbonate is 99.8%, the purity of ammonium chloride is 99.8%, and the utilization rate of sodium chloride is 94.5%.
Example 6
A method for separating alkali salt by chemical sublimation-temperature change crystallization in Hou's combined alkali preparation comprises the following steps:
(1) dissolving sodium chloride with high-purity water by ultrasonic to prepare a saturated sodium chloride aqueous solution, wherein the mass concentration of the sodium chloride is 40%, continuously introducing ammonia gas into an ammoniation tower to absorb the sodium chloride solution into an ammoniated high-salt solution, wherein the molar ratio of the ammonia gas to the sodium chloride is 2:1, the ammoniation reaction temperature is 50 ℃, the ammoniation time is 1h, and the reaction pressure is 0.5 MPa. Conveying the ammonium high-salt solution to a carbonization tower through a metering pump, and continuously introducing carbon dioxide gas to process the ammonium high-salt solution into a mixed solution containing bicarbonate, wherein the molar ratio of carbon dioxide to sodium chloride in the carbonization reaction is 1.2:1, the carbonization reaction temperature is 40 ℃, the carbonization time is 0.6h, and the reaction pressure is 0.4 MPa;
(2) separating out sodium bicarbonate crystals from the mixed solution containing the bicarbonate at a crystallization temperature of 75 ℃; calcining the sodium bicarbonate crystals at 260 ℃ for 0.6h to obtain a sodium carbonate product, and collecting and recycling generated carbon dioxide gas; and carrying out chemical sublimation, desublimation and drying on the crude ammonium chloride product to obtain an ammonium chloride product, wherein the sublimation temperature is 350 ℃, the desublimation temperature is 68 ℃, the pressure in the process is 0.3MPa, the high-temperature crystallization temperature is 20 ℃, and the low-temperature crystallization temperature is 10 ℃. The content of sodium chloride impurities in the ammonium chloride product is reduced to below 50 ppm. Collecting ammonia released after chemical sublimation, and circularly sleeving the ammonia into the ammonification tower;
the yield of sodium carbonate in the product prepared by the embodiment is 92.6%, the yield of ammonium chloride is 92.8%, the purity of sodium carbonate is 99.6%, the purity of ammonium chloride is 99.7%, and the utilization rate of sodium chloride is 94.9%.
Example 7
A method for separating alkali salt by chemical sublimation-temperature change crystallization in Hou's combined alkali preparation comprises the following steps:
(1) dissolving sodium chloride with high-purity water by ultrasonic to prepare a saturated sodium chloride aqueous solution, wherein the mass concentration of the sodium chloride is 40%, continuously introducing ammonia gas into an ammoniation tower to absorb the sodium chloride solution into an ammoniated high-salt solution, wherein the molar ratio of the ammonia gas to the sodium chloride is 1.5:1, the ammoniation reaction temperature is 40 ℃, the ammoniation time is 0.8h, and the reaction pressure is 0.1 MPa. Conveying the ammonium high-salt solution to a carbonization tower through a metering pump, and continuously introducing carbon dioxide gas to process the ammonium high-salt solution into a mixed solution containing bicarbonate, wherein the molar ratio of carbon dioxide to sodium chloride in the carbonization reaction is 1.2:1, the carbonization reaction temperature is 40 ℃, the carbonization time is 0.6h, and the reaction pressure is 0.4 MPa;
(2) separating out sodium bicarbonate crystals from the mixed solution containing the bicarbonate at a crystallization temperature of 65 ℃; calcining the sodium bicarbonate crystals at 260 ℃ for 0.6h to obtain a sodium carbonate product, and collecting and recycling generated carbon dioxide gas; and carrying out chemical sublimation, desublimation and drying on the crude ammonium chloride product to obtain an ammonium chloride product, wherein the sublimation temperature is 350 ℃, the desublimation temperature is 68 ℃, the pressure in the process is 0.3MPa, the high-temperature crystallization temperature is 20 ℃, and the low-temperature crystallization temperature is 10 ℃. The content of sodium chloride impurities in the ammonium chloride product is reduced to below 50 ppm. Collecting ammonia released after chemical sublimation, and circularly sleeving the ammonia into the ammonification tower;
the yield of sodium carbonate in the product prepared by the embodiment is 94.5%, the yield of ammonium chloride is 93.8%, the purity of sodium carbonate is 99.7%, the purity of ammonium chloride is 99.9%, and the utilization rate of sodium chloride is 95.4%.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and their concepts should be equivalent or changed within the technical scope of the present invention.
Claims (9)
1. A method for separating alkali salt by chemical sublimation-temperature change crystallization in Hou's combined alkali preparation is characterized by comprising the following steps:
(1) dissolving sodium chloride with high-purity water by ultrasonic to prepare a supersaturated sodium chloride aqueous solution, conveying the supersaturated sodium chloride aqueous solution into an ammoniation tower through a metering pump, continuously introducing ammonia gas to perform an ammoniation process to absorb the ammoniated sodium chloride aqueous solution into an ammoniated high-salt solution, conveying the ammoniated high-salt solution into a carbonization tower through the metering pump, and continuously introducing carbon dioxide gas to perform a carbonization process to process the ammoniated high-salt solution into a mixed solution containing bicarbonate;
(2) filtering and washing a mixed solution containing bicarbonate to obtain an alkali salt crude product containing sodium bicarbonate and ammonium chloride, decomposing the sodium bicarbonate through a high-temperature calcination process to obtain a sodium carbonate product, and circularly sleeving carbon dioxide tail gas generated in the calcination process into the carbonization tower after washing and pressurizing; carrying out chemical sublimation, desublimation and drying on the ammonium chloride crude product to obtain an ammonium chloride product, collecting ammonia gas released after chemical sublimation, and circularly sleeving the ammonia gas into the ammonification tower;
(3) the filtered mother liquor is an aqueous solution containing ammonium chloride and sodium chloride, a sodium chloride crude product is separated out through a high-temperature crystallization process, and the sodium chloride product is further refined through recrystallization, decoloration and drying processes; then, the crude product of ammonium chloride is separated out through the low-temperature crystallization process, and is further refined into an ammonium chloride product through the recrystallization, decoloration and drying processes, so that the impurity content of sodium chloride in the ammonium chloride product is reduced to be below 50 ppm; collecting ammonia released in the high-temperature crystallization process, circularly using the ammonia in the ammoniation tower, circularly using residual liquid obtained after low-temperature crystallization and recrystallization as an aqueous solution in which sodium chloride and ammonium chloride are dissolved in the carbonizer.
2. The method for separating alkali salt through chemical sublimation-temperature change crystallization in Hou's combined soda production according to claim 1, wherein in the ammoniation process in the step (1), a saturated aqueous solution of sodium chloride is sprayed and flowed in through a metering pump through the top of an ammoniation tower, and is subjected to countercurrent chemical absorption with ammonia gas blown in from the bottom of the tower, the saturated aqueous solution of sodium chloride and the ammonia gas are subjected to full mixing reaction, the gas is introduced into the tower from the top of the tower from a waste gas pipeline in a tangential direction, and is subjected to circulating treatment, and a spraying device is arranged at the top of the inner side of the tower; controlling the retention time of the saturated sodium chloride aqueous solution in the ammoniation tower through the flow rate, and enabling the ammoniated high-salt solution after chemical absorption to flow out from an overflow port at the top of the tower; the concentration of the sodium chloride saturated aqueous solution is 20-50% (mass concentration), the molar ratio of ammonia gas to sodium chloride is 1.0-2.0: 1, the ammoniation temperature is 30-50 ℃, the ammoniation time is 0.5-1 h, and the pressure is 0.1-0.5 MPa.
3. The method for separating alkali salt through chemical sublimation-temperature change crystallization in Hou's integrated soda production according to claim 1, wherein in the carbonization step (1), the ammonium high-salt solution is sprayed and flowed in through a metering pump through the top of the carbonization tower and is subjected to countercurrent chemical absorption with carbon dioxide blown in from the bottom of the tower, the ammonium high-salt solution and the carbon dioxide gas are subjected to full mixing reaction, the gas is introduced into the tower from the top of the tower from a waste gas pipeline in a tangential direction, and a spraying device is arranged at the top of the inner side of the tower; controlling the retention time of the high-salt ammoniated solution in the carbonization tower through the flow rate, and enabling the high-salt ammoniated solution after chemical absorption to flow out from an overflow port at the top of the tower; the molar ratio of the carbon dioxide gas to the ammonium high-salt solution is 1.0-1.5: 1, the carbonization temperature is 20-45 ℃, the carbonization time is 0.5-1 h, and the pressure is 0.1-0.5 MPa.
4. The method for separating alkali salt through chemical sublimation-temperature change crystallization in Hou's combined alkali preparation according to claim 1, wherein the high-temperature calcination process in step (2) is continuously performed in a tubular furnace, the temperature in a hearth is adjusted through a temperature control system, the temperature is programmed to rise (the temperature rise rate is 10 ℃/min), the crude alkali salt containing sodium bicarbonate and ammonium chloride is mechanically conveyed and continuously enters a cavity of the tubular furnace for high-temperature calcination, the crude sodium bicarbonate is decomposed to obtain a sodium carbonate product, the calcination temperature is 200-280 ℃, and the calcination time is 0.5-1 h.
5. The method for separating alkali salt through chemical sublimation-temperature change crystallization in Hou's combined alkali production according to claim 1, wherein the chemical sublimation and desublimation process in step (2) is performed in a sublimation-desublimation separation system, which is formed by connecting a raw material buffer tank, a feeding pump, a discharging pump, a sublimation kettle, a desublimation kettle, a preheater, a condenser and a circulating pump in sequence, wherein inert particles are placed in the sublimation kettle to prevent solid bumping, and the ammonium chloride crude product is pyrolyzed by the sublimation system to generate NH3And HCl gas, then through a condensing system NH3Reacts rapidly with HCl to regenerate fine NH4A Cl crystal, wherein the sublimation temperature is 340-360 ℃, the desublimation temperature is 65-70 ℃, and the pressure is 0.1-0.5 MPa; the inert particles comprise one or more of glass beads, agate beads, ceramic plates, quartz sand, activated carbon, molecular sieves, fillers (pall rings and Raschig rings), fiber balls and the like; the shape is one or more of spherical, cylindrical, regular hexahedral, tetrahedral, sheet, oval, needle-shaped, strip-shaped, annular, saddle-shaped, grid plate, corrugated plate and the like; the diameter is 1-10 mm.
6. The method for separating alkali salt by chemical sublimation-temperature change crystallization in Hou's combined alkali preparation according to claim 1, characterized in that the high-temperature crystallization process and the low-temperature crystallization process in the step (3) are continuously carried out in a dual-temperature zone crystallization reactor and a crystallization separator, the temperature control system is used for adjusting the temperature change of different areas in the reactor, the high-efficiency separation of sodium chloride and ammonium chloride is carried out by adopting a mode of zone control and sectional feeding, regulating the temperature of the zone (the temperature rise rate of the high temperature zone is 2 ℃/min, the temperature drop rate of the low temperature zone is 1 ℃/min) by program temperature change, carrying out high temperature zone crystallization and low temperature zone crystallization on mother liquor containing ammonium chloride and sodium chloride in a crystallization reactor, respectively obtaining sodium chloride and ammonium chloride crystals by a separator, the temperature of the high-temperature crystallization zone is controlled to be 20-30 ℃, and the temperature of the low-temperature crystallization zone is controlled to be 10-15 ℃.
7. The method for separating alkali salt through chemical sublimation-temperature change crystallization in Hou's combined alkali preparation according to claim 2, wherein the ammoniation process conditions in the step (1) are preferably to control the concentration of a saturated aqueous solution of sodium chloride to be 30-40% (mass concentration), the molar ratio of ammonia gas to sodium chloride is 1.0-1.5: 1, the ammoniation temperature is 30-40 ℃, the ammoniation time is 0.6-0.8 h, and the pressure is 0.2-0.3 MPa; the preferable conditions of the carbonization process are that the molar ratio of the carbon dioxide gas to the ammonium high-salt solution is controlled to be 1.0-1.2: 1, the carbonization temperature is 30-40 ℃, the carbonization time is 0.5-0.6 h, and the pressure is 0.2-0.4 MPa.
8. The method for separating alkali salt through chemical sublimation-temperature change crystallization in Hou's combined alkali preparation according to claim 4, wherein the conditions of the high-temperature calcination process in the step (2) are preferably 250-260 ℃ of calcination temperature and 0.6-0.8 h of calcination time; the conditions of the chemical sublimation and desublimation processes in the step (2) are preferably 340-350 ℃ of sublimation temperature, 68-70 ℃ of desublimation temperature and 0.2-0.3 MPa of pressure.
9. The method for separating alkali salt by chemical sublimation-temperature change crystallization in Hou's combined alkali preparation according to claim 6, wherein the conditions of the high temperature crystallization process and the low temperature crystallization process in the step (3) are preferably that the temperature of the high temperature crystallization zone is controlled to be 20-25 ℃ and the temperature of the low temperature crystallization zone is controlled to be 10-12 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210145771.4A CN114477230A (en) | 2022-02-17 | 2022-02-17 | Method for separating alkali salt through chemical sublimation-temperature-changing crystallization in Hou's combined alkali preparation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210145771.4A CN114477230A (en) | 2022-02-17 | 2022-02-17 | Method for separating alkali salt through chemical sublimation-temperature-changing crystallization in Hou's combined alkali preparation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114477230A true CN114477230A (en) | 2022-05-13 |
Family
ID=81482211
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210145771.4A Pending CN114477230A (en) | 2022-02-17 | 2022-02-17 | Method for separating alkali salt through chemical sublimation-temperature-changing crystallization in Hou's combined alkali preparation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114477230A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115634900A (en) * | 2022-11-29 | 2023-01-24 | 国能龙源环保有限公司 | Method and system for recycling solid waste miscellaneous salt resources |
| CN117865183A (en) * | 2024-03-08 | 2024-04-12 | 山东海天生物化工有限公司 | Clean production process for improving crystallinity granularity of re-ash |
| CN117865183B (en) * | 2024-03-08 | 2024-07-09 | 山东海天生物化工有限公司 | Clean production process for improving crystallinity granularity of re-ash |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2007135924A (en) * | 2007-09-27 | 2009-04-10 | ОАО "Березниковский содовый завод" (RU) | METHOD FOR PRODUCING CALCINATED SODA |
| CN102085422A (en) * | 2009-12-08 | 2011-06-08 | 沈善明 | Continuous vacuum dynamic sublimation and desublimation machine |
| CN103880046A (en) * | 2014-03-17 | 2014-06-25 | 中国中轻国际工程有限公司 | Technology for co-production of sodium carbonate, sodium chloride and ammonium chloride through calcium type rock salt brine and flue gas of boiler |
| CN108585089A (en) * | 2018-05-24 | 2018-09-28 | 苏州鼎昌节能环保科技有限公司 | A kind of sodium chloride ammonium chloride divides salt crystallization processes and device |
| CN109289230A (en) * | 2018-08-08 | 2019-02-01 | 浙江工业大学 | A kind of closed cycle-inert particles fluidized bed serialization sublimating and condensing separating refining device and process for refining |
| CN113135582A (en) * | 2021-04-01 | 2021-07-20 | 常州大学 | Production method for jointly preparing sodium carbonate and ammonium chloride by using sodium chloride |
-
2022
- 2022-02-17 CN CN202210145771.4A patent/CN114477230A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2007135924A (en) * | 2007-09-27 | 2009-04-10 | ОАО "Березниковский содовый завод" (RU) | METHOD FOR PRODUCING CALCINATED SODA |
| CN102085422A (en) * | 2009-12-08 | 2011-06-08 | 沈善明 | Continuous vacuum dynamic sublimation and desublimation machine |
| CN103880046A (en) * | 2014-03-17 | 2014-06-25 | 中国中轻国际工程有限公司 | Technology for co-production of sodium carbonate, sodium chloride and ammonium chloride through calcium type rock salt brine and flue gas of boiler |
| CN108585089A (en) * | 2018-05-24 | 2018-09-28 | 苏州鼎昌节能环保科技有限公司 | A kind of sodium chloride ammonium chloride divides salt crystallization processes and device |
| CN109289230A (en) * | 2018-08-08 | 2019-02-01 | 浙江工业大学 | A kind of closed cycle-inert particles fluidized bed serialization sublimating and condensing separating refining device and process for refining |
| CN113135582A (en) * | 2021-04-01 | 2021-07-20 | 常州大学 | Production method for jointly preparing sodium carbonate and ammonium chloride by using sodium chloride |
Non-Patent Citations (1)
| Title |
|---|
| 文建光主编: "纯碱与烧碱", 化学工业出版社 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115634900A (en) * | 2022-11-29 | 2023-01-24 | 国能龙源环保有限公司 | Method and system for recycling solid waste miscellaneous salt resources |
| CN117865183A (en) * | 2024-03-08 | 2024-04-12 | 山东海天生物化工有限公司 | Clean production process for improving crystallinity granularity of re-ash |
| CN117865183B (en) * | 2024-03-08 | 2024-07-09 | 山东海天生物化工有限公司 | Clean production process for improving crystallinity granularity of re-ash |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108046295B (en) | Method for producing sodium bicarbonate and ammonium sulfate by using sodium sulfate solution | |
| CN113135582A (en) | Production method for jointly preparing sodium carbonate and ammonium chloride by using sodium chloride | |
| CN114436297B (en) | Method for preparing sodium carbonate from mirabilite | |
| CN112850745A (en) | Method for recycling waste incineration fly ash | |
| CN108726542A (en) | The production method and production equipment of sodium bicarbonate | |
| CN110589857A (en) | Method for preparing alkali by using waste salt in combination manner | |
| CN112225235A (en) | Method for preparing sodium bicarbonate and sodium bisulfate from sodium sulfate | |
| CN111099698A (en) | Forward osmosis and combined soda production process co-production combined system and method | |
| CN114162837A (en) | Waste salt recycling treatment system and treatment method thereof | |
| CN113896208A (en) | Method for treating industrial mixed waste salt by using sulfuric acid | |
| CN113636576A (en) | System and method for disposing and recycling miscellaneous salt in coal chemical industry | |
| CN114715919B (en) | Method for preparing sodium bicarbonate and co-producing ammonium chloride by using sodium chloride waste salt | |
| CN114477230A (en) | Method for separating alkali salt through chemical sublimation-temperature-changing crystallization in Hou's combined alkali preparation | |
| CN113522934B (en) | System and method for waste incineration flue gas purification and fly ash desalination | |
| CN114436296A (en) | Continuous production method for jointly preparing sodium carbonate and ammonium chloride by using sodium chloride | |
| CN213446254U (en) | System for calcium sulfate is prepared and hydrochloric acid is retrieved to calcium chloride | |
| CN112279277A (en) | System and method for high-end resource utilization of flue gas desulfurization by magnesium method | |
| WO1994018360A1 (en) | Process for recovering solid sodium bicarbonate from diaphragm cell | |
| CN114769293B (en) | Method for cooperative treatment of industrial solid waste and resource utilization of industrial waste salt | |
| CN208732632U (en) | The production equipment of sodium bicarbonate | |
| CN110844926A (en) | Production method of high-purity magnesium sulfite | |
| CN109354047A (en) | A method of preparing high-purity magnesium oxide | |
| CN113044857B (en) | Production process for preparing high-purity sodium cyanide or potassium cyanide with high yield | |
| CN114477250A (en) | Method for preparing magnesium sulfate by using anthraquinone waste acid | |
| CN114455612A (en) | Novel process for preparing soda ash byproduct gypsum by using sodium sulfate and carbon dioxide as raw materials |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |