CN113955773B - System and method for separating sodium sulfate in modal fiber acid bath - Google Patents
System and method for separating sodium sulfate in modal fiber acid bath Download PDFInfo
- Publication number
- CN113955773B CN113955773B CN202111306438.9A CN202111306438A CN113955773B CN 113955773 B CN113955773 B CN 113955773B CN 202111306438 A CN202111306438 A CN 202111306438A CN 113955773 B CN113955773 B CN 113955773B
- Authority
- CN
- China
- Prior art keywords
- primary
- acid bath
- vacuum
- sodium sulfate
- separation
- 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.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D5/00—Sulfates or sulfites of sodium, potassium or alkali metals in general
- C01D5/16—Purification
-
- 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
Abstract
The invention relates to a viscose fiber production technology, in particular to a separation system and a separation method of sodium sulfate in a modal fiber acid bath, comprising an acid-cooled crystallization device, a primary vacuum separation device, a flash evaporation and denitration device, a secondary vacuum separation device and a drying device which can be communicated in sequence; the primary vacuum separation device comprises a primary suspension device, a primary belt type vacuum filter and a concentrated acid bath storage tank which are sequentially communicated; the secondary vacuum separation device comprises a secondary suspension device, a secondary belt type vacuum filter and a neutralization barrel which are communicated in sequence. The system is provided with the vacuum separation device after the acid-cooled crystallization device and the flash evaporation and denitration device respectively, so that the yield of anhydrous sodium sulfate can be effectively improved. The method combines the acid-cooled crystallization and the one-step nitrate extraction method, and effectively solves the technical bottleneck of difficult separation of sodium sulfate in the modal fiber production process through twice vacuum separation.
Description
Technical Field
The invention relates to a viscose fiber production technology, in particular to a separation system and a separation method of sodium sulfate in a modal fiber acid bath.
Background
Sodium sulfate is an inorganic compound, sodium sulfate decahydrate is commonly known as mirabilite, and sodium sulfate in a high-purity, fine-grained anhydrous state is known as anhydrous sodium sulfate. Sodium sulfate is a substance which is inevitably generated in the main reaction of viscose fiber production.
In the production of viscose fibers, the acid bath reacts with viscose to produce water and sodium sulfate, and in order to maintain the constant composition of the acid bath, the excess water and the excess sodium sulfate in the acid bath need to be removed. The sodium sulfate content in the modal fiber acid bath is low due to the limitation of the modal fiber production process, sodium sulfate needs to be converted into mirabilite through an acid-cooled crystallization system, the sodium sulfate is crystallized and separated out from the acid bath, then the mirabilite is converted into anhydrous sodium sulfate through a roasting system, and then the qualified anhydrous sodium sulfate is generated through a drying system.
In the traditional process, the mirabilite separation technology is vacuum rotary drum centrifuge separation, the problem of low centrifuge production capacity exists, and meanwhile, the surfaces of the centrifugal machine rotating hub, the rotating hub pressing ring, the distributing disc and other flow-through parts are easy to erode, so that the operation failure rate of the centrifugal machine is high, and the equipment maintenance cost is high; the method for converting mirabilite into anhydrous sodium sulfate mainly realizes dehydration through high-temperature roasting, and the development of modal fiber is restricted by high energy consumption.
Disclosure of Invention
The invention aims to provide a separation system and a separation method for sodium sulfate in a modal fiber acid bath.
The technical scheme for solving the technical problems is as follows: a separation system and a separation method of sodium sulfate in a modal fiber acid bath.
The invention provides a separation system of sodium sulfate in a modal fiber acid bath, which comprises an acid-cooled crystallization device, a primary vacuum separation device, a flash evaporation and denitration device, a secondary vacuum separation device and a drying device which can be communicated in sequence; the primary vacuum separation device comprises a primary suspension device, a primary belt type vacuum filter and a concentrated acid bath storage tank which are sequentially communicated; the secondary vacuum separation device comprises a secondary suspension device, a secondary belt type vacuum filter and a neutralization barrel which are sequentially communicated.
The technical scheme of the invention has the beneficial effects that the vacuum separation devices are respectively arranged behind the acid-cooled crystallization device and the flash evaporation and nitrate extraction device, so that the mirabilite separated out after acid-cooled crystallization can be effectively filtered and separated, the conversion rate of one-step nitrate extraction in the flash evaporation and nitrate extraction device is improved, and the high-purity anhydrous sodium sulfate is obtained through the secondary vacuum separation device. The system and the method combine the acid-cooled crystallization treatment with the one-step denitration treatment, and have the characteristic of saving steam; meanwhile, because the belt type vacuum filter system has large separation capacity, small solid particles can be effectively separated, and therefore, the relative yield of anhydrous sodium sulfate is higher than that of the traditional centrifuge system.
The technical scheme of the invention can be implemented by the following further technical scheme:
further, the primary vacuum separation device also comprises a primary water ring vacuum pump, and the primary water ring vacuum pump is communicated with the primary tail gas treatment device; the primary water ring vacuum pump is also communicated with the top of at least one primary gas-liquid separation tank; the top of each primary gas-liquid separation tank is respectively communicated with the vacuum box of the primary belt type vacuum filter; the bottom of each primary gas-liquid separation tank is respectively communicated with a primary mother liquor tank; the secondary vacuum separation device further comprises a secondary water ring vacuum pump, and the secondary water ring vacuum pump is communicated with the secondary tail gas treatment device; the secondary water ring vacuum pump is also communicated with the top of at least one secondary gas-liquid separation tank; the top of each secondary gas-liquid separation tank is respectively communicated with the vacuum box of the secondary belt type vacuum filter; the bottom of each secondary gas-liquid separation tank is respectively communicated with the secondary mother liquor tank.
The technical scheme has the beneficial effects that the water ring vacuum pump can provide negative pressure for the gas-liquid separation tanks, so that the mother liquor of the belt type vacuum filter is absorbed into each gas-liquid separation tank, and the separation of the mother liquor and acid gas is realized in the gas-liquid separation tank.
Further, the primary vacuum separation device also comprises a primary cooling water storage tank and a primary cooling water tower which are sequentially connected end to form a circulation loop; the primary water ring vacuum pump, the primary cooling water storage tank and the primary cooling water tower are sequentially communicated end to end; the secondary vacuum separation device further comprises a secondary cooling water storage tank and a secondary cooling water tower which are sequentially connected end to form a circulation loop; the secondary water ring vacuum pump, the secondary cooling water storage tank and the secondary cooling water tower are sequentially communicated end to end.
The water ring vacuum pump has the beneficial effects that water used by the water ring vacuum pump can be recycled, and the waste of water is avoided.
Further, the primary mother liquid tank is communicated with a primary acid bath storage tank, and the primary acid bath storage tank is communicated with the top of the primary suspension device; the secondary mother liquid tank is communicated with a secondary acid bath storage tank; the secondary acid bath storage tank is communicated with the top of the secondary suspension device.
The technical proposal has the advantages that the filtered mother solution in the mother solution tank and the supernatant in the suspension device can be collected in the acid bath storage tank, and the collected solution can be prepared again for production after being collected.
Further, the secondary vacuum separation device also comprises a densifier and a spray pipe; the neutralization barrel is communicated with the drying device through a pipeline, and the densifier is arranged on the pipeline, through which the neutralization barrel is communicated with the drying device; a spray head is fixedly arranged at one end of the spray pipe and is positioned above the secondary belt type vacuum filter; the other end of the spray pipe is communicated with the densifier.
The adoption of the further technical scheme has the beneficial effects that the supernatant in the thickener is used for spraying the secondary belt type vacuum filter, and because the supernatant is saturated sodium sulfate solution, the sodium sulfate filter cake can be sprayed by replacing production water to effectively remove residual acid liquor in the sodium sulfate filter cake, the sulfuric acid content of the sodium sulfate filter cake is below 0.2% after the sodium sulfate filter cake is leached by the spraying liquid, the caustic soda consumption is reduced, and meanwhile, the spraying liquid can not dissolve the sodium sulfate, so that the sodium sulfate dissolution loss is reduced, and the sodium sulfate yield is improved.
Further, the secondary vacuum separation device also comprises a centrifuge; the centrifugal machine is arranged on a pipeline which is communicated with the thickener and the drying device.
The technical scheme has the beneficial effects that the centrifugal machine can further separate the anhydrous sodium sulphate solid from the solution, so that the purity of the anhydrous sodium sulphate is further improved.
The invention provides a separation method for sodium sulfate in a modal fiber acid bath by adopting the separation system, which comprises the following steps:
s1, carrying out acid-cooling crystallization treatment on a modal fiber acid bath solution to obtain a mirabilite acid bath mixed solution;
s2, carrying out primary vacuum separation on the mirabilite acid bath mixed solution to obtain a mirabilite filter cake;
s3, adding the concentrated acid bath solution subjected to flash evaporation into the mirabilite filter cake to obtain a concentrated acid bath mixed solution of the mirabilite filter cake;
s4, performing one-step denitration treatment on the mirabilite filter cake concentrated acid bath mixed liquor to obtain anhydrous sodium sulfate concentrated acid bath mixed liquor;
s5, carrying out secondary vacuum separation on the concentrated acid bath mixed liquor of anhydrous sodium sulfate to obtain an anhydrous sodium sulfate filter cake;
s6, regulating the pH value of the anhydrous sodium sulfate filter cake to be neutral, and then drying to obtain anhydrous sodium sulfate.
The method of the invention has the beneficial effects that: according to the separation system and the separation method, the modal fiber acid bath can be subjected to acid cooling crystallization, primary vacuum separation, one-step nitrate extraction, secondary vacuum separation and drying in sequence, so that anhydrous sodium sulfate is finally obtained; the separation system can combine the acid-cooled crystallization and the one-step nitrate extraction treatment method, and combines two vacuum separation, thereby effectively solving the problem of high energy consumption caused by adopting a roasting process and centrifugal separation in the traditional method.
Further, in the step S1, the vacuum degree of the acid-cooled crystallization treatment is 50-120 Kpa, and the final acid falling temperature is 3-10 ℃.
Further, in the step S2, the pressure range of the primary vacuum separation is-0.01 Mpa to-0.05 Mpa.
Further, in the step S5, the pressure range of the secondary vacuum separation is-0.01 Mpa to-0.05 Mpa.
Drawings
FIG. 1 is a schematic diagram of the structure of a separation system for sodium sulfate in a modal fiber acid bath of the present invention;
FIG. 2 is a schematic diagram of a primary vacuum separation device in one embodiment of the separation system of sodium sulfate in a modal fiber acid bath of the present invention;
FIG. 3 is a schematic diagram of a secondary vacuum separation device in one embodiment of the separation system of sodium sulfate in a modal fiber acid bath of the present invention;
FIG. 4 is a flow chart of a process for separating sodium sulfate from a modal fiber acid bath of the present invention.
In the drawings, the list of components represented by the various numbers is as follows:
1. a first-stage suspension device; 11. a secondary suspension device;
2. a first-stage distributing device; 21. a secondary distributor;
3. a primary belt vacuum filter; 31. A secondary belt vacuum filter;
4. a first-stage gas-liquid separation tank; 41. A second-stage gas-liquid separation tank;
5. a concentrated acid bath storage tank; 51. a neutralization barrel;
6. a first stage filter cake collection tank; 61. A second-stage filter cake collecting tank;
7. a first stage rinse water storage tank; 71. A second stage rinse water storage tank;
8. a primary mother liquor tank; 81. A secondary mother liquor tank;
9. a first-stage liquid accumulation tank; 91. A secondary liquid sump;
10. a primary cooling water storage tank; 101. A secondary cooling water storage tank;
12. a primary water ring vacuum pump; 121. A secondary water ring vacuum pump;
13. a primary tail gas treatment device; 131. A secondary tail gas treatment device;
14. a first-stage cooling tower; 141. A secondary cooling tower;
15. a primary acid bath storage tank; 151. A secondary acid bath storage tank;
16. a first-level adhesive tape flushing nozzle; 161. A secondary adhesive tape flushing nozzle;
17. a densifier; 18. a shower pipe; 19. a centrifuge; 20. a drying device;
100. an acid-cooled crystallization device; 200. a primary vacuum separation device; 300. flash evaporation and nitrate extraction device; 400. a secondary vacuum separation device.
Detailed Description
The principles and features of the present invention are described below with reference to the drawings, the examples are illustrated for the purpose of illustrating the invention and are not to be construed as limiting the scope of the invention.
As shown in fig. 1 to 3, the separation system and method of sodium sulfate in a modal fiber acid bath of the present invention comprises an acid-cooled crystallization device 100, a primary vacuum separation device 200, a flash evaporation and denitration device 300, a secondary vacuum separation device 400 and a drying device 20 which can be communicated in sequence; the primary vacuum separation device 200 comprises a primary suspension device 1, a primary belt type vacuum filter 3 and a concentrated acid bath storage tank 5 which are sequentially communicated; the secondary vacuum separation apparatus 400 includes a secondary suspension 11, a secondary belt vacuum filter 31, and a neutralization drum 51, which are sequentially connected.
According to the separation system and the separation method, a vacuum separation device is respectively arranged behind the acid-cooled crystallization device 100 and the flash evaporation and denitration device 300, so that mirabilite separated out after acid-cooled crystallization can be effectively filtered and separated, the conversion rate of one-step denitration in the flash evaporation and denitration device 300 is improved, and a sodium sulfate filter cake is obtained through the secondary vacuum separation device 400; stirring the sodium sulfate filter cake in a neutralization barrel 51 to form sodium sulfate solid-liquid mixed solution, regulating the pH value to be neutral 6-8, and carrying out centrifugal separation and drying on the sodium sulfate solid-liquid mixed solution to obtain the high-purity sodium sulfate. The separation system and the separation method can combine the acid-cooled crystallization and the one-step nitrate extraction treatment method together and combine the two vacuum separation, thereby effectively solving the problem of high energy consumption caused by adopting a roasting process and centrifugal separation in the traditional method.
The acid-cooled crystallization device 100 of the present invention controls the vacuum of the crystallization system and the temperature of each crystallization chamber, and then the sodium sulfate with low concentration in the acid bath is crystallized to produce mirabilite after water is distilled out.
The invention relates to a one-step nitrate extraction system, in particular to a flash evaporation nitrate extraction system, which can convert sodium sulfate decahydrate (mirabilite) into sodium sulfate (anhydrous sodium sulfate) through flash evaporation.
The primary vacuum separation apparatus 200 and the secondary vacuum separation apparatus 400 of the present invention can theoretically employ any apparatus capable of performing vacuum separation instead of the centrifuge for filtering.
The drying device 20 may be a dryer, a pressure dryer, or the like.
As shown in fig. 2, for the primary vacuum separation apparatus 200, in one embodiment of the present invention, there is the following structure:
in the embodiment, a first-stage filter cake collecting tank 6 is arranged between the first-stage belt type vacuum filter 3 and the concentrated acid bath storage tank 5; the feed inlet of the first-stage filter cake collecting tank 6 corresponds to the discharge end of the first-stage belt type vacuum filter 3; the first-stage filter cake collecting tank 6 is communicated with the concentrated acid bath storage tank 5 through a pipeline; the acid bath solution from which the mirabilite is separated by acid-cooled crystallization is subjected to vacuum separation on the filter cloth and the adhesive tape of the primary belt type vacuum filter 3, when the acid solution is separated, the acid solution passes through the filter cloth, is gathered through the transverse grooves on the adhesive tape and enters the vacuum box through the small holes, the mirabilite solid particles are trapped to form a filter cake, the mirabilite filter cake is gradually deacidified along with the movement of the adhesive tape, finally the filter cloth is separated from the adhesive tape, the filter cake is discharged at the discharge end through the scraper blade, and the filter cake enters the primary filter cake collecting tank 6 to be collected.
After the first-stage filter cake collecting tank 6 collects the mirabilite filter cake, the flashed concentrated acid bath solution is added into the first-stage filter cake collecting tank, the mirabilite filter cake and the concentrated acid bath solution are mixed again to form mixed liquor, and the mixed liquor enters the concentrated acid bath storage tank 5 through a pipeline which is communicated with the concentrated acid bath storage tank 5 through the first-stage filter cake collecting tank 6, and is ready to enter a one-step nitric acid extraction system for one-step nitric acid extraction treatment.
Preferably, the primary belt type vacuum filter 3 of the embodiment is provided with a primary distributor 2 at the upper part of the feeding end, the primary distributor 2 is communicated with the primary suspension device 1, and the bottom of the primary distributor 2 is provided with a distributing port; the acid bath solution from which mirabilite is separated out through acid-cooled crystallization enters a first-stage distributing device 2 from a first-stage suspension device 1, and then enters a filter cloth of a first-stage belt type vacuum filter 3 from a distributing port at the bottom of the first-stage distributing device 2 for vacuum separation; the primary distributor 2 can uniformly flatten the entered mixed liquid, so that the filtering efficiency and the effect are improved, and meanwhile, the material distribution speed can be adjusted according to the running speed of the primary belt type vacuum filter 3, so that the material distribution is more uniform, and the vacuum separation effect is improved.
Preferably, the primary suspension device 1 of the embodiment is positioned above the primary distributor 2, and the primary distributor 2 is positioned above the primary belt type vacuum filter 3; the primary suspension device 1 is a tank body with a thickening effect, and the bottom of the primary suspension device is a cone; when the acid bath solution from which the mirabilite is separated out through acid-cooled crystallization is arranged in the first-stage suspension device 1, the mirabilite of solid particles can be relatively thickened; the specific thickening mode is that the solution enters the primary suspension device 1 from the tangential position, so that the solution is subjected to tangential centrifugal force to realize thickening; like this, through the first-stage suspension ware 1 back of thickening, its bottom regional solution concentration increases, and the upper portion region is the supernatant, like this, when the solution that bottom concentration is high carries out vacuum separation on first-stage belt vacuum filter 3, can be separated fast, effectively improved treatment effeciency.
Preferably, after thickening by primary suspension 1, the concentration of the fixed particles can reach more than 10%.
Preferably, in the present embodiment, the primary vacuum separation device 200 further includes a primary water ring vacuum pump 12, where the primary water ring vacuum pump 12 is communicated with the tops of the plurality of primary gas-liquid separation tanks 4, and each primary gas-liquid separation tank 4 is respectively communicated with the vacuum box of the primary belt vacuum filter 3; the primary water ring vacuum pump 12 can provide negative pressure for the primary gas-liquid separation tank 4, so that mother liquor of the primary belt type vacuum filter 3 is absorbed into each primary gas-liquid separation tank 4, and separation of the mother liquor and acid gas is realized in the primary gas-liquid separation tank 4.
The primary water ring vacuum pump 12 is also communicated with a primary tail gas treatment device 13, and each primary gas-liquid separation tank 4 is respectively communicated with a primary mother liquid tank 8; mother liquor separated in the primary gas-liquid separation tank 4 falls into the primary mother liquor tank 8 under the action of gravity, and acid gas enters the primary water ring vacuum pump 12 through the top of the primary gas-liquid separation tank 4 and then enters the primary tail gas treatment device 13.
The primary mother liquor tank 8 is also communicated with a primary acid bath storage tank 15, so that mother liquor in the primary mother liquor tank 8 can be collected; the primary acid bath storage tank 15 is also communicated with the primary suspension device 1; the supernatant liquid in the primary suspension device 1 can enter a primary acid bath storage tank 15, the supernatant liquid and the mother liquor are acid liquid, and after the acid liquid is collected, a certain amount of sulfuric acid can be added into the acid liquid for spinning.
The primary water ring vacuum pump 12 is also communicated with the primary cooling water storage tank 10 and the primary cooling water tower 14 in turn from end to end; because the operation of the primary water ring vacuum pump 12 needs to be pumped with water to realize vacuumizing, the water inlet of the primary water ring vacuum pump is communicated with the primary cooling water tower 14, the water outlet of the primary water ring vacuum pump is communicated with the primary cooling water storage tank 10, and the primary cooling water tower 14 and the primary cooling water storage tank 10 are also communicated, the water of the primary water ring vacuum pump 12 can be recycled, the transitional consumption of water is prevented, and meanwhile, the cost is saved; the primary cooling tower 14 serves to cool the circulating water.
Preferably, the primary vacuum separation device 200 of the present embodiment further includes a primary tape flushing nozzle 16, a primary liquid sump 9, and a primary shower water storage tank 7; the primary adhesive tape flushing nozzle 16 is fixed on the primary belt type vacuum filter 3 and positioned below the discharge end of the primary belt type vacuum filter 3 and is used for flushing the adhesive tape of the primary belt type vacuum filter 3; the primary liquid accumulation tank 9 is arranged at the lower side of the primary belt type vacuum filter 3 and is used for collecting water after the adhesive tape is washed; the primary leaching water storage tank 7 is respectively communicated with the primary liquid accumulation tank 9 and the primary adhesive tape flushing nozzle 16 through pipelines, and pumps are arranged on the pipelines communicated with the primary adhesive tape flushing nozzle 16, so that water collected in the primary leaching water storage tank 7 can be recycled to the primary adhesive tape flushing nozzle 16.
Preferably, the pipeline for communicating the primary leaching water storage tank 7 with the primary adhesive tape flushing nozzle 16 can also be filled with production water, so that the flushing effect is prevented from being reduced due to excessive circulating times of the circulating water.
As shown in fig. 3, for the secondary vacuum separation apparatus 400, in one embodiment of the present invention, there is the following structure:
in the embodiment, a secondary filter cake collecting tank 61 is arranged between the secondary belt type vacuum filter 31 and the neutralization barrel 51; the feed inlet of the secondary filter cake collecting tank 61 corresponds to the position of the discharge end of the secondary belt vacuum filter 31; the acid bath solution of the anhydrous sodium sulfate obtained by one-step nitrate extraction through the flash evaporation and nitrate extraction device 300 is subjected to vacuum separation on the filter cloth and the adhesive tape of the secondary belt type vacuum filter 31, when in separation, acid liquor passes through the filter cloth, is gathered through the transverse grooves on the adhesive tape and enters the vacuum box through the small holes, the anhydrous sodium sulfate solid particles are trapped to form a filter cake, the anhydrous sodium sulfate filter cake is gradually deacidified along with the movement of the adhesive tape, finally the filter cloth is separated from the adhesive tape, the filter cake is discharged at the discharge end through the arranged scraping plate, and the filter cake enters the secondary filter cake collecting tank 61 to be collected.
Preferably, the secondary belt vacuum filter 31 of the embodiment is provided with a secondary distributor 21 at the upper part of the feeding end, the secondary distributor 21 is communicated with the secondary suspension 11, and the bottom of the secondary distributor 21 is provided with a distributing port; the acid bath solution of the sodium sulfate which is subjected to one-step nitrate extraction by the flash evaporation and nitrate extraction device 300 enters the secondary distributor 21 from the secondary suspension device 11, and then enters the filter cloth and the adhesive tape of the secondary belt type vacuum filter 31 from the distribution port at the bottom of the secondary distributor 21 for vacuum separation; the secondary distributor 21 can uniformly flatten the entered mixed liquid, so as to improve the filtering efficiency and effect, and meanwhile, the speed for distributing the material can be adjusted according to the running speed of the secondary belt type vacuum filter 31, so that the material distribution is more uniform, and the vacuum separation effect is improved.
Preferably, the secondary suspension device 11 of the present embodiment is located above the secondary distributor 21, and the secondary distributor 21 is located above the secondary belt vacuum filter 31; the secondary suspension device 11 is a tank body with a thickening effect, and the bottom of the secondary suspension device is a cone; the specific thickening mode is that the solution enters the secondary suspension device 11 from the tangential position, so that the solution is subjected to tangential centrifugal force to realize thickening; thus, after the concentration of the solution passing through the secondary suspension device 11 is increased, the concentration of the solution in the bottom area is increased, and the upper area is supernatant, so that when the solution with high concentration at the bottom is subjected to vacuum separation on the secondary belt type vacuum filter 31, the solution can be rapidly separated, and the treatment efficiency is effectively improved.
Preferably, after enrichment by secondary suspension 11, the fixed particle concentration can reach more than 10.5%.
Preferably, in the present embodiment, the secondary vacuum separation device 400 further includes a secondary water ring vacuum pump 121, where the secondary water ring vacuum pump 121 is communicated with the tops of the plurality of secondary gas-liquid separation tanks 41, and each secondary gas-liquid separation tank 41 is respectively communicated with the vacuum box of the secondary belt vacuum filter 31; the secondary water ring vacuum pump 121 can provide negative pressure for the secondary gas-liquid separation tanks 41, so that the mother liquor of the secondary belt type vacuum filter 31 is absorbed into each secondary gas-liquid separation tank 41, and separation of the mother liquor and acid gas is realized in the secondary gas-liquid separation tank 41.
The secondary water ring vacuum pump 121 is also communicated with a secondary tail gas treatment device 131, and each secondary gas-liquid separation tank 41 is respectively communicated with a secondary mother liquid tank 81; mother liquor separated in the secondary gas-liquid separation tank 41 falls into the secondary mother liquor tank 81 by gravity, and acid gas enters the secondary water ring vacuum pump 121 through the top of the secondary gas-liquid separation tank 41 and then enters the secondary tail gas treatment device 131.
The secondary mother liquor tank 81 is also communicated with the secondary acid bath storage tank 151, so that mother liquor in the secondary mother liquor tank 81 can be collected; the secondary acid bath storage tank 151 is also communicated with the secondary suspension device 11; the supernatant liquid in the secondary suspension device 11 can enter a secondary acid bath storage tank 151, the supernatant liquid and the mother liquor are acid liquid, and after the acid liquid is collected, a certain amount of sulfuric acid can be added into the acid liquid for spinning.
The secondary water ring vacuum pump 121 is also communicated with the secondary cooling water storage tank 101 and the secondary cooling water tower 141 in turn from end to end; because the operation of the secondary water ring vacuum pump 121 needs to be pumped with water to realize vacuumizing, the water inlet of the secondary water ring vacuum pump is communicated with the secondary cooling water tower 141, the water outlet of the secondary water ring vacuum pump is communicated with the secondary cooling water storage tank 101, and the secondary cooling water tower 141 is also communicated with the secondary cooling water storage tank 101, so that the water of the secondary water ring vacuum pump 121 can be recycled, the transition consumption of water is prevented, and meanwhile, the cost is saved; the secondary cooling tower 141 serves to cool down the circulating water.
Preferably, the secondary vacuum separation apparatus 400 of the present embodiment further includes a secondary tape flushing nozzle 161, a secondary liquid sump 91, and a secondary rinse water storage tank 71; the secondary adhesive tape flushing nozzle 161 is fixed on the secondary belt type vacuum filter 31 and is positioned below the discharge end of the secondary belt type vacuum filter 31 for flushing the adhesive tape of the secondary belt type vacuum filter 31; the secondary liquid sump 91 is disposed at the lower side of the secondary belt vacuum filter 31 and is used for collecting water after the adhesive tape is rinsed; the secondary rinsing water storage tank 71 is respectively communicated with the secondary liquid accumulation tank 91 and the secondary adhesive tape flushing nozzle 161 through pipelines, and pumps are arranged on the pipelines communicated with the secondary adhesive tape flushing nozzle 161, so that water collected in the secondary rinsing water storage tank 71 can be recycled to the secondary adhesive tape flushing nozzle 161.
Preferably, the pipeline of the secondary rinsing water storage tank 71 communicated with the secondary adhesive tape rinsing nozzle 161 can also be filled with production water, so that the rinsing effect is prevented from being reduced due to excessive circulating times of circulating water.
Preferably, the secondary filter cake collection tank 61 is in communication with the neutralization drum 51 via a conduit, and the neutralization drum 51 is in communication with the densifier 17 via a conduit; after the second-stage filter cake collecting tank 61 collects the anhydrous sodium sulphate filter cake, the anhydrous sodium sulphate filter cake is transferred to the neutralization barrel 51; adding alkali into the neutralization barrel 51 to adjust the pH value, and when the pH value is neutral and is 6-8, preparing the mixture to enter the densifier 17 for densification.
The secondary vacuum separation device 400 of the embodiment is also provided with a spray pipe 18 and a centrifugal machine 19; one end of the spray pipe 18 is fixedly provided with a spray head, and the spray head is positioned in a vacuum box of the secondary belt type vacuum filter 31 and above an adhesive tape of the secondary belt type vacuum filter 31; the other end of the spray pipe 18 is communicated with a thickener 17; the densifier 17 is respectively communicated with the neutralization bucket 51 and the centrifugal machine 19, and the centrifugal machine 19 is communicated with the drying device 20; the second-stage belt type vacuum filter 31 is provided with a washing area corresponding to the spray pipe 18, the mixed solution of anhydrous sodium sulfate and acid bath enters the second-stage belt type vacuum filter 31 and moves along with the adhesive tape, under the action of vacuum, acid liquor passes through the filter cloth, is gathered through transverse grooves on the adhesive tape and enters a vacuum box through small holes, solid anhydrous sodium sulfate particles are trapped to form a filter cake, the filter cake after being formed sequentially enters the washing area and a drying area outside the washing area along with the movement of the adhesive tape, finally the filter cloth is separated from the adhesive tape, and the filter cake is discharged from a filter cake discharging roller through a scraping plate.
Preferably, the spray liquid of the spray pipe 18 is the supernatant liquid in the thickener 17, the solution is saturated sodium sulfate solution, and the flow rate is 1-3 m 3 The temperature is 40-50 ℃ between/h.
The high-temperature saturated sodium sulfate solution is used for replacing production water to spray the anhydrous sodium sulfate filter cake, so that residual acid liquor in the anhydrous sodium sulfate filter cake can be effectively removed, the sulfuric acid content of the anhydrous sodium sulfate filter cake is below 0.2% after the anhydrous sodium sulfate filter cake is leached by the spray solution, caustic soda consumption is reduced, the anhydrous sodium sulfate cannot be dissolved by the spray solution, the dissolving loss of the anhydrous sodium sulfate is reduced, and the anhydrous sodium sulfate yield is improved.
Preferably, in the above embodiment, the rotation speed of the primary belt vacuum filter 3 and the secondary belt vacuum filter 31 is 20 to 35Hz.
Preferably, the vacuum boxes of the primary distributor 2, the secondary distributor 21 and the belt vacuum filters are made of stainless steel 904.
As shown in fig. 4, the separation system and method of sodium sulfate in a modal fiber acid bath provided by the invention are characterized by comprising the following steps:
s1, introducing a modal fiber acid bath solution into an acid-cooled crystallization device 100, and performing acid-cooled crystallization treatment to obtain a mirabilite acid bath mixed solution.
Preferably, the feeding amount of the acid-cooled crystallization treatment is 15-25 m 3 And/h, the vacuum degree is 50-120 Kpa, and the final acid dropping temperature is 3-10 ℃.
Preferably, the feeding amount of the Modal acid bath after the acid-cooled crystallization treatment is 20-25 m 3 And/h, the vacuum degree is 50-100 Kpa, the final stage acid dropping temperature is 3-8 ℃, and the content of mirabilite in the mirabilite bath mixed solution is 10-15%.
S2, introducing the mirabilite acid bath mixed solution into a primary vacuum separation device 200, and performing primary vacuum separation to obtain a mirabilite filter cake.
Preferably, the pressure range of primary vacuum separation is-0.01 Mpa to-0.05 Mpa.
The content of sodium sulfate in the mirabilite filter cake is 30-42%.
S3, adding the flashed concentrated acid bath solution into the mirabilite filter cake to obtain a mirabilite concentrated acid bath mixed solution; the purpose of the concentrated acid bath solution after flash evaporation is to dissolve mirabilite and carry out one-step denitration.
S4, introducing the mirabilite concentrated acid bath mixed liquor into a one-step nitric acid extraction system, and carrying out nitric acid extraction treatment to obtain anhydrous sodium sulfate concentrated acid bath mixed liquor; the one-step nitrate extraction system is particularly a flash evaporation system, and mirabilite can be converted into anhydrous sodium sulfate in a flash evaporation mode.
And S5, introducing the concentrated acid bath mixed liquor of the anhydrous sodium sulfate into a secondary vacuum separation device 400, and performing secondary vacuum separation to obtain an anhydrous sodium sulfate filter cake.
Preferably, the pressure range of the secondary vacuum separation is-0.01 Mpa to-0.05 Mpa.
Preferably, the solid content of the anhydrous sodium sulphate filter cake is 80% -90%, and the sulfuric acid content is 0-0.5%;
s6, forming sodium sulfate solid-liquid mixed solution in a neutralization barrel, regulating the pH value of the sodium sulfate solid-liquid mixed solution to be neutral 6-8, and then moving the neutral 6-8 sodium sulfate filter cake into the drying device 20 for drying to obtain the sodium sulfate.
The working process of the separation system and method of the present invention is specifically described below by way of examples:
example 1
The acid bath in the modal fiber production process is treated with the above-described system and method of the present invention to separate sodium sulfate therefrom.
Firstly, introducing a modal fiber acid bath into an acid-cooled crystallization device 100 for acid-cooled crystallization treatment, wherein the specific treatment method comprises the steps of cooling and concentrating the modal fiber acid bath in the acid-cooled crystallization device 100, and obtaining an acid bath containing low-concentration mirabilite in a vacuum state; the feeding amount of the acid-cooled crystallization treatment is 20m 3 /h, vacuumThe final stage acid dropping temperature is 3 ℃ and the solid content of mirabilite in the mirabilite acid bath mixed solution is 15 percent, wherein the degree is 50 Kpa.
Introducing the mirabilite acid bath mixed solution into a primary suspension device 1 for centrifugal thickening, and then enabling the mirabilite acid bath mixed solution to enter a primary belt type vacuum filter 3 through a primary distributor 2; simultaneously, the primary water ring vacuum pump 12 is started to vacuumize the vacuum box of the primary belt type vacuum filter 3, so that vacuum separation is implemented.
The device is operated in the primary water ring vacuum pump 12, wherein the used circulating water passes through the primary cooling water storage tank 10 and is cooled by the primary cooling water tower 14 and then is recycled into the primary water ring vacuum pump 12, so that the circulating use is realized; wherein, the water flow of the primary water ring vacuum pump 12 is 5m 3 /h。
Simultaneously, the primary adhesive tape flushing nozzle 16 is started to flush the adhesive tape of the primary belt type vacuum filter 3, and simultaneously, flushing water circulates through the primary liquid accumulation tank 9 and the primary leaching water storage tank 8. Wherein, the rinsing water flow rate of the primary adhesive tape rinsing nozzle 16 is 3m 3 /h。
In addition, the filtrate box receives the filtered filtrate, the gas in the filtrate is separated and circulated into the primary tail gas treatment device 13 through the primary gas-liquid separation tank 4, and the filtrate enters the primary mother liquid tank 8 to be collected.
In the process, the pressure of the primary belt type vacuum filter 3 is-0.03 Mpa, and the rotating speed is 30Hz. The yield of the obtained mirabilite filter cake is 6.3t/h, and the content of anhydrous sodium sulfate in the mirabilite filter cake is 42%.
The mirabilite filter cake enters a first-stage filter cake collecting tank 6, the flash evaporation concentrated acid bath is introduced into the first-stage filter cake collecting tank 6, the mixed solution of the mirabilite and the concentrated acid bath is obtained again, and the mixed solution is conveyed into a concentrated acid bath storage tank 5 and is dissolved in the concentrated acid bath storage tank 5.
Introducing the concentrated acid bath in the concentrated acid bath storage tank 5 into a one-step nitrate extraction system, and in the one-step nitrate extraction system, removing water and thickening through flash evaporation to obtain the mixed liquor of anhydrous sodium sulfate and the concentrated acid bath.
The mixed solution of anhydrous sodium sulfate and concentrated acid bath is introduced into a secondary vacuum separation device 400, the treatment process of the secondary vacuum separation device 400 is similar to that of the primary vacuum separation device 200, and the pressure of the secondary belt type vacuum filter 31 is-0.03 Mpa.
The flow rate of the shower pipe 18 was 3m when the secondary vacuum separation apparatus 400 was used for the treatment 3 /h; the content of anhydrous sodium sulfate in the anhydrous sodium sulfate filter cake is 90 percent, and the content of sulfuric acid is 0.1 percent.
The anhydrous sodium sulphate filter cake enters a neutralization barrel 51, alkali is added in the neutralization barrel 51 to adjust the PH value of the water, the liquid-solid salt slurry mixed liquid in the neutralization barrel 51 enters a sleeve of a thickener 17 through a salt slurry pump, after sedimentation and thickening through the thickener 17, the anhydrous sodium sulphate slurry enters a centrifuge 19, and after centrifugal dehydration, the anhydrous sodium sulphate slurry enters a drying device 20 to remove water, so that the anhydrous sodium sulphate is obtained.
Example 2
The same procedure as in example 1 was used to produce anhydrous sodium sulfate, and in this example, the acid-cooled crystallization treatment was carried out with a feed rate of 20m 3 And/h, the vacuum degree is 80Kpa, the final stage acid dropping temperature is 5 ℃, and the solid content of mirabilite in the mirabilite acid bath mixed solution is 13%.
The pressures of the primary belt type vacuum filter 3 and the secondary belt type vacuum filter 31 are both-0.03 Mpa, and the rotating speed is 30Hz; the yield of the obtained mirabilite filter cake is 6.5t/h, and the content of anhydrous sodium sulfate in the mirabilite filter cake is 40%.
The flow rate of the shower pipe 18 was 2.2m 3 /h; the content of anhydrous sodium sulfate in the anhydrous sodium sulfate filter cake is 90.1 percent and the content of sulfuric acid is 0.15 percent.
Example 3
The same procedure as in example 1 was used to produce anhydrous sodium sulfate, and in this example, the acid-cooled crystallization treatment was carried out with a feed rate of 20m 3 And/h, the vacuum degree is 100Kpa, the final stage acid dropping temperature is 8 ℃, and the solid content of mirabilite in the mirabilite acid bath mixed solution is 10%.
The pressures of the primary belt type vacuum filter 3 and the secondary belt type vacuum filter 31 are both-0.03 Mpa, and the rotating speed is 20Hz; the yield of the obtained mirabilite filter cake is 4.3t/h, and the content of anhydrous sodium sulfate in the mirabilite filter cake is 42%.
The flow rate of the shower pipe 18 was 1m 3 /h; the content of anhydrous sodium sulfate in the anhydrous sodium sulfate filter cake is 90.3 percent and the content of sulfuric acid is 0.2 percent.
Compared with the technical scheme of the invention, if the secondary vacuum separation is not carried out after the one-step denitration treatment, a large amount of caustic soda is needed to be used when the pH value is regulated, so that the efficiency is low and the cost is increased.
The energy consumption of the three embodiments is calculated, and the method and the system replace a traditional process high-temperature roasting system, so that the energy consumption is reduced, the power consumption is reduced by 30Kw/h on average, and the steam consumption is reduced by 1.5 tons/ton of anhydrous sodium sulfate on average; finally, the content of sulfuric acid in the anhydrous sodium sulphate filter cake is reduced, and the content of sulfuric acid is effectively reduced through washing in a washing area, so that the consumption of caustic soda is reduced, and the consumption of caustic soda is reduced by approximately 5 kg/ton of silk on average.
In modal fiber production, the acid-cooled crystallization parameters are different and the mirabilite particle size is different. The separation of mirabilite by the centrifuge can only retain particles larger than the gap between the screens of the centrifuge, and the belt type vacuum filter system can retain mirabilite with smaller particle size, so that the yield of mirabilite obtained by the primary belt type vacuum filter 3 is obviously increased.
The vacuum of the belt vacuum filter system is related to the thickness of a material layer, when the thickness of the material layer is 2-3 cm, the vacuum is between-0.02 and-0.04 Mpa, the separation efficiency of the belt vacuum filter is closely related to the vacuum and the rotating speed, and when the vacuum degree is constant, the smaller the rotating speed of the belt vacuum filter is, the higher the separation efficiency is, but the lower the yield is; while the higher the rotational speed, the lower the separation efficiency, but the greater the yield. Through the embodiment, the thickness of the material layer of the belt type vacuum filter system is controlled to be 2-3 cm, the vacuum degree is controlled to be between-0.02 and-0.04 Mpa, and the rotating speed is controlled to be 25-35 Hz.
In the description of the present invention, it should be noted that the azimuth or positional relationship indicated by "up", "down", etc. is based on the azimuth or positional relationship shown in the drawings, and is merely for convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element to be referred to must have a specific azimuth, be configured and operated in a specific azimuth, and thus should not be construed as limiting the present invention.
Furthermore, the terms "primary" and "secondary" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a stage", "a second stage" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.
In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
The foregoing description of the preferred embodiments of the invention is not intended to limit the invention to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the invention are intended to be included within the scope of the invention.
Claims (9)
1. A method for separating sodium sulfate in a modal fiber acid bath, comprising the steps of:
s1, carrying out acid-cooling crystallization treatment on a modal fiber acid bath solution to obtain a mirabilite acid bath mixed solution;
s2, carrying out primary vacuum separation on the mirabilite acid bath mixed solution to obtain a mirabilite filter cake;
s3, adding the concentrated acid bath solution subjected to flash evaporation into the mirabilite filter cake to obtain a concentrated acid bath mixed solution of the mirabilite filter cake;
s4, performing one-step denitration treatment on the mirabilite filter cake concentrated acid bath mixed liquor to obtain anhydrous sodium sulfate concentrated acid bath mixed liquor;
s5, carrying out secondary vacuum separation on the concentrated acid bath mixed liquor of anhydrous sodium sulfate to obtain an anhydrous sodium sulfate filter cake;
s6, regulating the pH value of the anhydrous sodium sulfate filter cake to be neutral, and then drying to obtain anhydrous sodium sulfate;
the separation method is implemented by adopting a separation system of sodium sulfate in a modal fiber acid bath, and the separation system comprises an acid-cooled crystallization device (100), a primary vacuum separation device (200), a flash evaporation and denitration device (300), a secondary vacuum separation device (400) and a drying device (20) which can be communicated in sequence;
the primary vacuum separation device (200) comprises a primary suspension device (1), a primary belt type vacuum filter (3) and a concentrated acid bath storage tank (5) which are sequentially communicated; the secondary vacuum separation device (400) comprises a secondary suspension device (11), a secondary belt type vacuum filter (31) and a neutralization barrel (51) which are sequentially communicated.
2. The method for separating sodium sulfate in a modal fiber acid bath according to claim 1, wherein the primary vacuum separation device (200) further comprises a primary water ring vacuum pump (12), and the primary water ring vacuum pump (12) is communicated with a primary tail gas treatment device (13); the primary water ring vacuum pump (12) is also communicated with the top of at least one primary gas-liquid separation tank (4); the top of each primary gas-liquid separation tank (4) is respectively communicated with a vacuum box of the primary belt type vacuum filter (3); the bottom of each primary gas-liquid separation tank (4) is respectively communicated with a primary mother liquid tank (8);
the secondary vacuum separation device (400) further comprises a secondary water ring vacuum pump (121), and the secondary water ring vacuum pump (121) is communicated with the secondary tail gas treatment device (131); the secondary water ring vacuum pump (121) is also communicated with the top of at least one secondary gas-liquid separation tank (41); the top of each secondary gas-liquid separation tank (41) is respectively communicated with a vacuum box of the secondary belt type vacuum filter (31); the bottom of each secondary gas-liquid separation tank (41) is respectively communicated with a secondary mother liquid tank (81).
3. A process for the separation of sodium sulphate in a modal fibre acid bath as claimed in claim 2 characterised in that,
the primary vacuum separation device (200) further comprises a primary cooling water storage tank (10) and a primary cooling water tower (14) which are sequentially connected end to form a circulation loop; the primary water ring vacuum pump (12), the primary cooling water storage tank (10) and the primary cooling water tower (14) are communicated end to end in sequence;
the secondary vacuum separation device (400) further comprises a secondary cooling water storage tank (101) and a secondary cooling water tower (141) which are sequentially connected end to form a circulation loop; the secondary water ring vacuum pump (121), the secondary cooling water storage tank (101) and the secondary water cooling tower (141) are communicated end to end in sequence.
4. A method for separating sodium sulphate from modal fibre acid bath according to claim 2, characterised in that the primary mother liquor tank (8) is in communication with a primary acid bath storage tank (15), the primary acid bath storage tank (15) being in communication with the top of the primary suspension (1);
the secondary mother liquid tank (81) is communicated with a secondary acid bath storage tank (151); the secondary acid bath storage tank (151) is communicated with the top of the secondary suspension device (11).
5. The method for separating sodium sulfate from a modal fiber acid bath according to any one of claims 1-4, characterized in that the secondary vacuum separation apparatus (400) further includes a densifier (17) and a shower pipe (18);
the neutralization barrel (51) is communicated with the drying device (20) through a pipeline, and the thickener (17) is arranged on the pipeline, in which the neutralization barrel (51) is communicated with the drying device (20);
a spray head is fixedly arranged at one end of the spray pipe (18), and the spray head is positioned above the secondary belt type vacuum filter (31); the other end of the spray pipe (18) is communicated with the thickener (17).
6. The method for separating sodium sulfate from a modal fiber acid bath according to claim 5, characterized in that the secondary vacuum separation apparatus (400) further includes a centrifuge (19); the centrifugal machine (19) is arranged on a pipeline for communicating the thickener (17) with the drying device (20).
7. The method for separating sodium sulfate from a modal fiber acid bath according to claim 1, wherein in the step S1, the vacuum degree of the acid-cooled crystallization treatment is 50-120 Kpa, and the final acid falling temperature is 3-10 ℃.
8. The method for separating sodium sulfate from a modal fiber acid bath according to claim 1, wherein in the step S2, the pressure of the primary vacuum separation ranges from-0.01 Mpa to-0.05 Mp.
9. The method for separating sodium sulfate from a modal fiber acid bath according to claim 1, wherein in the step S5, the pressure of the secondary vacuum separation ranges from-0.01 Mpa to-0.05 Mpa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111306438.9A CN113955773B (en) | 2021-11-05 | 2021-11-05 | System and method for separating sodium sulfate in modal fiber acid bath |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111306438.9A CN113955773B (en) | 2021-11-05 | 2021-11-05 | System and method for separating sodium sulfate in modal fiber acid bath |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113955773A CN113955773A (en) | 2022-01-21 |
| CN113955773B true CN113955773B (en) | 2023-10-10 |
Family
ID=79469429
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111306438.9A Active CN113955773B (en) | 2021-11-05 | 2021-11-05 | System and method for separating sodium sulfate in modal fiber acid bath |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113955773B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115253545B (en) * | 2022-07-26 | 2023-10-10 | 唐山三友集团兴达化纤有限公司 | Method and system for recycling dedusting water in viscose staple fiber production process |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1214272A (en) * | 1997-10-10 | 1999-04-21 | 邵明福 | Continuous stirring vacuum sodium sulfate crystallization technology |
| CN103241748A (en) * | 2013-04-27 | 2013-08-14 | 许达人 | Process method for preparing anhydrous sodium sulphate based on flash vaporization crystallization of acid bath |
| CN103510166A (en) * | 2012-06-20 | 2014-01-15 | 杭州奥通科技有限公司 | High wet modulus viscose fiber coagulating bath processing assembly line |
| CN112704900A (en) * | 2020-12-17 | 2021-04-27 | 唐山三友集团兴达化纤有限公司 | Acid bath treatment method in modal fiber production process |
-
2021
- 2021-11-05 CN CN202111306438.9A patent/CN113955773B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1214272A (en) * | 1997-10-10 | 1999-04-21 | 邵明福 | Continuous stirring vacuum sodium sulfate crystallization technology |
| CN103510166A (en) * | 2012-06-20 | 2014-01-15 | 杭州奥通科技有限公司 | High wet modulus viscose fiber coagulating bath processing assembly line |
| CN103241748A (en) * | 2013-04-27 | 2013-08-14 | 许达人 | Process method for preparing anhydrous sodium sulphate based on flash vaporization crystallization of acid bath |
| CN112704900A (en) * | 2020-12-17 | 2021-04-27 | 唐山三友集团兴达化纤有限公司 | Acid bath treatment method in modal fiber production process |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113955773A (en) | 2022-01-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113955773B (en) | System and method for separating sodium sulfate in modal fiber acid bath | |
| CN108358220B (en) | Method and device for producing baking soda | |
| CN104058433B (en) | Process for fast sodium aluminate solution separation and red mud washing | |
| CN102371080B (en) | Crystallizing method utilizing external circulation of crystal slurry | |
| CN103241748B (en) | Process method for preparing anhydrous sodium sulphate based on flash vaporization crystallization of acid bath | |
| CN105983266A (en) | Continuous washing and separating method of polyphenylene sulfide | |
| CN211688287U (en) | Lithium hydroxide monohydrate crystallization separation purification device | |
| CN105502300B (en) | One kind separation sulfur-melting technology and equipment | |
| CN101264943B (en) | Water-saving discharge-reducing consume-reducing continuous production device for nickel carbonate | |
| CN107287958B (en) | A kind of equipment of cotton linter bleaching preparation purified cotton | |
| CN104418724B (en) | A kind of oxalic rare earth precipitates water wash system | |
| CN115043763B (en) | Gas-liquid continuous crystallization method of DL-methionine | |
| CN110606492A (en) | Method for continuously synthesizing white carbon black and sodium fluoride | |
| CN102897809A (en) | Method and equipment for separating and washing fly ash calcium silicate slag | |
| CN206126866U (en) | Novel environmental protection circulation process system of soda and sociation center | |
| CN115559024A (en) | Method for recycling waste polyacrylonitrile solution | |
| CN112704900B (en) | Acid bath treatment method in modal fiber production process | |
| CN214218200U (en) | System for viscose fiber acid bath integrated production anhydrous sodium sulphate | |
| CN204746008U (en) | Dust processing system in sulphur ammonium tail gas | |
| CN1267348C (en) | Solid-liquid separation technique for preparing high assay and industrial solid product of sodium cyanide | |
| CN220048135U (en) | Ferric phosphate continuous separation system | |
| CN103554952B (en) | Device for recycling mixed alkali from indigo-dyed product | |
| CN112062142A (en) | Method and device for preparing potassium chloride by using crude potassium | |
| CN220574195U (en) | Continuous washing device for battery-level ferric phosphate | |
| CN202876423U (en) | Acid bath flash evaporation and crystallization device |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |