CN1056779C - Continuously self-cooling crystalizing technology - Google Patents
Continuously self-cooling crystalizing technology Download PDFInfo
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Abstract
The present invention discloses a continuously self-cooling crystallizing technology of salts, and the reducing trend of the dissolvability of the salts following the reduction of temperature is not obvious in a salt-water system after crystallization operation temperature. The continuously self-cooling crystallizing technology of salts is characterized in that the cool clear liquid of crystallization solution is prefabricated; the cool clear liquid passes through a heat exchanger with self-purifying capability at self-purifying flow speed, and the cool clear liquid becomes super cool clear liquid in a temperature region with the non-obvious dissolvability trend by lowering temperature; the super cool clear liquid and the continuously supplied crystallization solution are in direct contact according to a circulation ratio K, the crystallization operation temperature is achieved by cooling, the operation of a crystallization process is carried out, a part of formed cool clear liquid circulates the step 2, the rest cool clear liquid overflows out of the system, and the rest cool clear liquid is recovered. The present invention has the characteristics of no easy crystallization scale generation, etc.
Description
The present invention belongs to a method for crystallizing salts in a water salt system, particularly to a method for continuously cooling and crystallizing.
The existing salt crystallization method is mainly based on the solubility characteristic and the characteristic shown on the solubility curve. The chemical engineering handbook, 6.1985, 9 th edition "evaporation and crystallization" pages 111-112 is divided into five categories as shown in FIG. 1, wherein the system represented by the solubility curve type of category V (i.e. curve V) is suitable for crystallization by cooling. The production hopes to adopt lower temperature and continuous mode to achieve the purpose of improving efficiency, but crystallization scale is generated on the heat exchange surface along with the cooling crystallization process, so that the thermal resistance is increased, the heat transfer capacity is weakened, the fluid resistance is increased, and the channel of the heat exchanger is seriously blocked so as to be forced to stop for cleaning or replacing the heat exchanger. There are therefore three general crystallization methods for group V systems: 1. the vacuum crystallization method has the defects that the energy consumption is far higher than that of a cooling method and the investment is large; 2. the direct contact method of refrigerant or refrigerant has the disadvantages that the selection of refrigerant or refrigerant is conditional, some are even harsh, and the whole device is required to be closed, and the like, so that the method is not common. 3. The intermittent dividing wall cooling method has the defects that the efficiency is too low, the crystallization scale on the outer wall of the coil heat exchanger or the inner wall of the crystallization kettle needs to be removed in time after each crystallization, the operation is heavy and time-consuming, the loss of cold energy is large, and the recycling is inconvenient.
Curve VI (i.e., type VI solubility curve) in FIG. 1 has not been reported or described in the prior art, and is subdivided as a single type in accordance with the practice of the invention based on the solubility characteristics of certain salts in the type V system and in order to facilitate the selection of the crystallization method. Specific solubility characteristics are described as: the solubility decreases less significantly with temperature. That is, as the temperature of the system decreases, the solubility decreases both significantly (the slope of the curve dc/dt tends to be large) and less significantly (the value of dc/dt tends to be small), i.e., the solubility is insensitive to temperature. The difference from the original solubility characteristics of the V type is that the characteristic that the change of the available solubility to the temperature is not obvious is added. However, this property has never been utilized in industrial production, and thus, the crystallization method of group V has been adopted.
In FIG. 1, curve IV shows that the solubility varies with decreasing temperature, and the solubility is moderately sensitive to temperature, and represents a system having a moderate slope dc/dt of the solubility curve, and therefore the disadvantages of mainly using vacuum or evaporative crystallization are the same as above; however, some salts may be crystallized by cooling method, i.e. intermittent dividing wall cooling crystallization, which has the same disadvantages as above, or by krystal-oslo cooling crystallization, which has the disadvantages that the temperature difference between the mixed solution and the cooling medium cannot be too large and is generally within 2 ℃ and the ratio of the circulating liquid to the feeding amount (i.e. the circulation ratio) is generally 50-200 times as large as that of industrial crystallization, 10 th edition of 1985, which is compiled by Dingtouhuai et al, and the like, so that the heat exchange area is large, the circulation amount is large, and the production capacity is small. Indeed, the solubility characteristics of some of the salts of group IV are also available in the form of their solubility characteristics, which are manifested by an insignificant decrease in solubility with temperature. This property has never been exploited in industrial production and all operate as described above for the type IV crystallization process.
The crystallization by the cooling method needs to determine the crystallization operation temperature, and generally, the temperature which has no practical significance is continuously reduced according to the reduction of the crystallization separation rate when the temperature is reduced. The crystallization operation temperature is therefore within a temperature range in which the change in solubility with respect to temperature tends to be insignificant. The present invention is based on the common solubility characteristics of salts of the type represented by the solubility curve of group VI and of the type IV, which are suitable for crystallization by cooling and have useful solubility characteristics, being: salts whose solubility decreases with temperature after the crystallization operating temperature tend to be insignificant.
The invention aims to provide a continuous cooling crystallization method which has the advantages that the circulation ratio of salt used is low, the solubility of the salt is not obvious along with the reduction of the temperature after the crystallization operation temperature, the temperature difference between the used temperature and a cooling medium of a crystallization solution is large, and a clear cold liquid is cooled to be a supercooled liquid in a temperature interval in which the solubility is insensitive to the temperature so as to cool the crystallization solution.
The purpose of the invention is realized as follows: in a water salt system, the continuous self-cooling crystallization of salts which are suitable for crystallization by cooling and have a solubility which does not decrease significantly with temperature after the crystallization operating temperature, comprises the following steps in sequence:
1) starting a cold clear liquid of the initial prefabricated crystallization solution, wherein the temperature of the cold clear liquid is in a temperature interval with unobvious solubility trend; 2) the cold clear liquid passes through a heat exchanger with self-purification capacity at the flow velocity generating self-purification effect to be cooled into supercooled liquid in a temperature interval with unobvious solubility trend; 3) directly contacting and cooling the supercooled liquid and the continuously fed crystallization solution at a circulation ratio K to reach a preset crystallization operation temperature, generating supersaturation, crystallization, growth, sedimentation and collection of crystal slurry, and circulating a part of formed cold clear liquid in the step 2) and overflowing the rest of the formed cold clear liquid out of the system.
In addition, the cold clear liquid overflowing out of the system can use a cold carrying medium to recover the cold energy of the cold clear liquid for precooling the continuously supplied crystallization solution, and the precooled crystallization solution is used for direct contact crystallization with the supercooled liquid in the step 3), and the residual cold is generally recovered by adopting a partition wall heat transfer mode or a direct contact heat transfer mode.
The start-up must be initiated by filling the crystallization apparatus with a cold clear solution of the crystallization solution, thus requiring prefabrication and only operating in a batch dividing wall cooling crystallization mode. The aim is to prevent the generation of crystal scale which is difficult to remove by fluid shearing force in the heat exchanger when the vehicle is started for circulation and temperature reduction at the beginning. The cold clear liquid is a saturated solution which is clarified at the crystallization operation temperature and is subjected to solid crystal slurry removal. The temperature of the cold clear liquid is reduced to be the supercooled liquid in a temperature range with unobvious solubility trend, and at the moment, although the state point of the solution already passes through a metastable zone, the supersaturation degree is lower, and only crystal nucleus generation and a small amount of crystallization precipitation are carried out; in order to prevent a small amount of crystals from depositing on the cooling surface of the heat exchanger, the heat exchanger used should have self-purification capability, and the commonly used heat exchangers have a spiral plate heat exchanger, a spiral tube heat exchanger and the like, and the cold clear liquid has a certain flow velocity which is generally 1-5M/S so as to generate self-purification or self-flushing action to reduce the chance of crystal sedimentation and adhesion and prolong the operation period.
Supercooled liquid and crystallization solution (or precooled to temperature T)cThe crystallization solution) is mixed in a certain ratio (i.e., the circulation ratio K) to reach the predetermined crystallization operation temperature TbWhere W is the weight flow rate of the supercooled liquid when the cold clear liquid is circulated and supercooled, and L is the weight flow rate of the continuously fed crystallization solution. Wherein K is in the range of 1-10. The cold clear liquid is heat exchanged with external cooling media such as frozen brine, ammonia and the like in a heat exchanger through a circulating pump to be cooled into a supercooled liquid. At the moment, the supercooled liquid is still in the crystallization area, and when the supercooled liquid is in direct contact with the continuously pumped precooled crystallization solution (or not precooled crystallization solution) in the mixing pipe according to the flow rate of the circulation ratio K, the supercooled liquid is cooled to reach the preset crystallizationSupersaturation, crystallization, growth and sedimentation are generated at the operation temperature, crystal mush is removed, and the obtained cold clear liquid is circulated into supercooled liquid according to the above steps. The overflowed cold clear liquid can be used for recovering residual cold to pre-cool the crystallization solution and then leave the system, so that a circulation process of cold clear liquid, namely, sub-cooled liquid, → self-cooled crystallization and cold clear liquid is formed. During the crystallization process, the crystal slurry is continuously or intermittently extracted to separate solid crystals, and simultaneously, the cold filtrate is returned to the crystallizer to avoid fluctuation and save energy.
The cooling medium used for recovering and pre-cooling the crystallization solution generally adopts water and air, a partition wall heat transfer device is adopted when water is taken as the cooling medium as shown in figure 2, and the modes of gas-liquid bubbling contact, gas-liquid spraying countercurrent contact, gas-liquid static mixing and the like are specifically shown in figure 3 when air is taken as the cooling medium, and the invention is helpful for understanding and implementing the invention by referring to figures 2-4.
The invention adopts the method that the salt with unobvious solubility along with the reduction trend of the temperature after the crystallization operation temperature is circularly cooled into the supercooled liquid by the prefabricated cold clear liquid, and then the supercooled liquid is contacted with the crystallization solution to reach the crystallization operation temperature for continuous crystallization, thereby having the advantages that: the crystallization solution with high concentration and easy scaling is cooled to generate supersaturation by adopting the supercooled liquid to be in direct contact with the supercooled liquid in the temperature interval with obviously reduced solubility, and the problem of crystallization scale generation does not exist without passing through a heat exchanger, and the crystallization solution is in the temperature interval with insensitive solubility to temperature when the cold clear liquid is circularly cooled to be the supercooled liquid through the heat exchanger, so that the crystallization scale is not easy to generate.
There are many salts in the water salt system which have a tendency not to show a significant decrease in solubility with temperature after the crystallization operation temperature. For example: in NaCl- -Na2SO4---H2Na in O-cosaturation system2SO4·10H2The solubility change of O is very small at the temperature of-5 to-20 ℃; KClO3At K+、Na+HCl-、ClO- 3+H2In the O system and in KClO3-KCl-H2The same characteristics are shown in the O system after the temperature is below 4 ℃; when the original concentration is over 58 percent and is excessive properly in the production of the nitric phosphate fertilizer by a freezing method, the precipitation rate of the calcium nitrate tetrahydrate at the temperature of between 0 and minus 20 ℃ is changed little; ammoniation method for producing K2SO4Reaction product K of potassium chloride and gypsum in ammonia liquor at 0 deg.C or below2SO4The solubility change is small; other examples include sodium phosphite (5-15 deg.C), CrO3(0～-155℃)，Zn(NO3)2(20～-18℃)、CO(NO3)2(20～-20℃)、FeCl3(0～-55℃)、Cu(NO3)2(0～-20℃)、2Na2CO3·3H2O2(0-5 ℃), borax (0-10 ℃), boric acid (0-15 ℃) and the like, which have little change in solubility in water. This general phenomenon makes the present invention not only practical but also quite versatile. Among the salts listed above, which are originally classified as group V or group IV, vacuum crystallization, batch-type inter-wall cooling crystallization, Krystal-oslo cooling crystallization, and the like are mainly used in industrial production. Indeed, these salts have available solubility characteristics suitable for use in the methods of the present invention. Therefore, the popularization and the application of the invention can generate great economic benefit and social benefit and help to change the laggard current situation of the domestic crystallization technology.
The invention is described in detail below with reference to the following figures and examples:
FIG. 1 is a chart of the solubility curve classification according to the present invention.
Fig. 2 is a schematic diagram of an apparatus using water as a cooling medium.
Fig. 3 is a schematic view of an apparatus using air as a cooling medium.
FIG. 4 is a flow chart of a continuous self-cooling crystallization process.
Description of the drawings:
curve I in fig. 1 indicates that the solubility of the salt is always negative with respect to temperature, and dc x/dt is negative; curve II shows that the solubility curve has a sharp transition point and instead decreases with increasing temperature, the dc x/dt value changes from positive to negative; curve III shows that the solubility is less sensitive to temperature, the dc/dt values are small; curve IV shows that the solubility varies generally with decreasing temperature, the solubility being moderately sensitive to temperature, i.e. having a moderate dc/dt value; curve V shows a significant decrease in solubility with decreasing temperature, the solubility being very temperature sensitive with a large dc/dt value; curve VI shows that the decrease in solubility with temperature tends to be insignificant from a significant decrease (dc x/dt shows the slope of the solubility curve, c x shows the equilibrium saturation solubility concentration, t is the temperature).
Fig. 2 shows that the crystallization solution is continuously pumped into the long groove stirring type crystallizer 5 and is cooled by the circulating cooling water in the water jacket, then enters the mixing pipe 4 together with the crystal slurry to be mixed with the super-cooling liquid phase from the crystallizer 1, the circulating pump 2 and the heat exchanger 3 to reach the crystallization operation temperature, the crystallization, the growth, the sedimentation and the like are carried out in the crystallizer 1, and the cold clear liquid which does not participate in the circulation overflows to enter the heat exchanger 7 to exchange with the circulating cooling water for recovering the residual cold. The cold filtrate after the crystal slurry separation solid crystallization returns to the mixing pipe 4.
Fig. 3 shows that the crystallization solution is continuously pumped into a static mixer 6 to be mixed with cold air, then the mixture is cooled and enters a mixing pipe 4, and gas after gas-liquid separation is discharged or circulated back to a fan 9 through a demister 5. The pre-cooled crystallization solution and the super-cooled liquid from the crystallizer 1, the circulating pump 2 and the heat exchanger 3 are mixed in the mixing pipe 4 to reach the crystallization operation temperature, the crystallization, the growth, the sedimentation and the like are carried out in the crystallizer 1, the cold clear liquid which does not participate in the circulation enters the static mixer 8 to be mixed with the air from the fan 9 and is separated in the gas-liquid separator 7, the clear mother liquid is separated from the system through the water seal 10, and the cold air enters the static mixer 6. The cold filtrate after the crystal slurry separation solid crystallization returns to the mixing pipe 4.
Both of FIGS. 2 and 3 are devices for pre-cooling the crystallization solution by recycling residual cold, and the non-recycling of residual cold can simplify the process and reduce the investment, but the energy loss is large and the cost is increased.
FIG. 4 combines FIGS. 2 and 3 and shows in block diagram the process of the continuous self-cooling crystallization process. The dotted lines in the figure indicate the flow direction of the cooling medium, which circulates if water is used as cooling medium, and which either empties or circulates if air is used as cooling medium, as the case may be.
Example 1 two-step Process for the production of KClO3Fraction ofAnd continuously cooling and crystallizing the mother liquor after decomposition.
The domestic potassium chlorate production mainly adopts double decomposition reaction of preparing sodium chlorate solution by electrolytic refined brine and potassium chloride and separates solid phase KClO3The later mother liquor contains saturated KClO3And NaCl, the KClO is taken out as much as possible in technological requirements3And the mother liquor is recycled. The current method mainly comprises vacuum crystallization or intermittent dividing wall cooling crystallization (mostly adopted in China), namely, KClO is frozen out by intermittently operating a mother solution in a groove type crystallizer at the temperature of between 3 ℃below zero and 4 ℃ below zero by using a coil heat exchanger3. According to the measured data KClO3The solubility change is small between-3 ℃ and-12 ℃, and the conditions for using the present invention are satisfied when the crystallization operation temperature is determined to be, for example, -4 ℃ in this interval. See examples table for methods. (1 denotes a non-precooled crystallization solution)
EXAMPLE 2 one-step production of KClO by direct electrolysis of KCl3Continuously cooling and crystallizing.
This process has been reported in inorganic salt industry No. 2.44 (1983). The solution circulation amount of the process is large, the crystallization efficiency is too low by adopting intermittent partition wall cooling, and the loss of cold energy is large; the energy consumption of evaporation or vacuum crystallization is too high, thereby influencing the popularization and application. According to the phase diagram KClO3The solubility change is small between-5 ℃ and-12 ℃, and the conditions for adopting the method are met when the crystallization operation temperature is determined to be-5 ℃ in the interval, and the method is shown in an example table (2 indicates that the crystallization solution is not precooled, and cooling water in a water jacket of a group of long-groove stirring type crystallizers is separately circulated and cooled by a cooling water tower for saving energy due to the higher temperature of the supplied crystallization solution).
Example 3 continuous cooling crystallization of nitrophosphate fertilizer produced by freezing method.
Removal of Ca (NO) from Nitrophosphate (NP) fertilizer by freezing method3)2·4H2And O, most domestic and overseas crystallization is carried out by adopting an intermittent partition wall or partition wallautomatic groove-reversing mode. The crystal scale on the pipe wall of the coil heat exchanger needs to be removed at the end of each process, and the process is time-consuming and inefficient. According to the physicochemical principle of the freezing process, when the original nitric acid concentration is 58-60%, the calcium removal rate is not obvious when the excessive 110% is between-5 ℃ and-20 ℃, and when the crystallization operation temperature is determinedThe degree of-6 ℃ meets the condition of adopting the invention. See examples table for methods.
Example 4, continuous denitration of glauberite underground salt mine brine.
Domestic underground salt mine resources are rich, and are vigorously developed and utilized in recent years. For containing SO2- 4Higher brines are generally more economical to freeze and can avoid Ba2+And (3) contamination. In Hubei chemical industry No. 4.18(1993), a method for precipitating crystals after three-stage continuous cooling by using a partition wall heat exchanger is introduced, which is used for SO2- 4Lower concentrations, e.g., below 15g/l, are possible. If the concentration is greatly exceeded, SO in the high-salt brine such as brine in Hunan, Yunnan and other places2- 4Even at levels above 50g/l, clogging in the heat exchanger can quickly occur in this way. According to the phase diagram, the solubility change of brine at-5 to-20 ℃ is not obvious, and the method is shown in an example table when the crystallization operation temperature is determined to be-6 ℃.
EXAMPLE 5 production of K from KCl and Gypsum by ammoniation2SO4Continuously cooling and crystallizing.
For KCl and CaSO at home and abroad4Preparation of K2SO4The process is of great interest because CaSO is present in ammonia liquor4、KCl、K2SO4、CaCl2Four salts alter the formation of K in a quaternary, interactive water-salt system2SO4The rather difficult situation is:
reaction product K2SO4The solubility in ammonia solution is extremely low, and the reaction proceeds in the positive direction. The conditions for applying the present invention are met when the crystallization operation temperature is determined to be 0 ℃. See examples table for methods.
Example 6, continuous cooling crystallization of sodium percarbonate produced by a wet process.
The wet process has various crystallization methods, and domestic enterprises all adopt low-temperature intermittent partition wall cooling crystallization. The low-temperature cooling crystallization is carried out by using saturated or supersaturated Na2CO3Adding hydrogen peroxide with a certain concentration and a certain quantity of stabilizer into the solutionThe sizing is carried out at 0-5 ℃.
According to the solubility data of sodium percarbonate in water: the solubility at temperatures below 5 ℃ is less likely to change with temperature, and the conditions for the use of the present invention are satisfied when the crystallization temperature is determined to be 5 ℃. The solubility of the salt does not change much at 5 ℃ or more, and belongs to the IV system. See examples table for methods.
Example 7, continuous purification of borax with boric acid.
The impurities are further reduced by industrial borax or boric acid through recrystallization, low-temperature crystallization is generally adopted to be beneficial to improving the yield, mother liquor is returned for utilization, and the existing method adopts intermittent partition wall cooling crystallization. According to the solubility data: the solubility of borax is changed very little at 0-15 ℃, and the solubility of boric acid is changed very little at 0-10 ℃, so that the method has the condition for adopting the invention. The solubility of the two products is not changed greatly above the crystallization operation temperature, and the products belong to a IV system. Two products are alternately recrystallized continuously by one set of device in one production plant, so that the investment is saved and the cost is reduced. See examples table for methods.
Examples table
Note: tm is the temperature of the crystallization solution entering the system, Te is the temperature of the precooled crystallization solution, Tb is the crystallization operation temperature, and Tc is the temperature of the supercooled liquid.
| Fruit of Chinese wolfberry Applying (a) to Example (b) | Prefabricated cold cleaner Method of preparing liquid | Parameters of temperature and circulation ratio | Heat exchanger Types of | Cold clear liquid Flow rate M/S | Salts To which it belongs Type (B) | Reference to Flow chart | Backup note | |
| Tm Te Tb Tc | K | |||||||
| 1 | Dissolving the crystal Liquid pump crystallization In-vivo utilization device Is arranged at the inside Coil pipe heat exchange Stirrer and agitator Freezing and forming And (4) crystallizing. When temperature is high To achieve the crystallization operation Stop after temperature Stopping cooling and stirring Stirring and standing for 1-2 Discharging crystals in small hours Slurry post-dismantling disc Pipe and stirrer Or can be at it In a container such as After prefabrication, the Pumping cold clear liquid into Full-filling crystallizer And (4) the following steps. | 28 18 -4 -12 | 2.5～3 | Spiral plate type Or Spiral tube type | 1.5～2.5 | VI | FIG. 2 | |
| 1 | 28 28 -4 -12 | 4～5 | Without precooling the crystallization solution (Tm ═ Te), without recycling and precoolingProvided is a device. | |||||
| 2 | 50 22 -5 -12 | 4～5 | Same as above | 1.5～2.5 | VI | FIG. 2 | Adding a group of long groove stirring crystallizers, cooling in water jackets thereof The water is separately circulated and cooled by a water cooling tower and then connected with the flow chart of figure 2. | |
| 2 | 50 50 -5 -12 | 2.5～3 | Same as example 1 | |||||
| 3 | 25 15 -6 -18 | 2～3 | Same as above | 2.5～4.5 | VI | FIG. 3 | ||
| 4 | 28 18 -6 -11 | 4～5 | Same as above | 2～3.5 | VI | FIG. 3 | ||
| 5 | 28 18 0 -8 | 2.5～3 | Same as above | 1.5～2.5 | VI | FIG. 3 | The circulating air contains ammonia, is not emptied and is recycled by a return fan. | |
| 6 | 30 20 5 -4 | 2～3 | Spiral plate type | 1～1.5 | IV | FIG. 3 | ||
| 7 | 45 30 15 0 | 1～2 | Same as above | 1～1.5 | IV | FIG. 2 or FIG. 3 | ||
| 45 30 10 0 | 3～4 | Same as above | 1～1.5 | IV | FIG. 2 or FIG. 3 | |||
Claims (6)
1. A method for continuous self-cooling crystallization of salts suitable for crystallization by cooling and having a solubility which does not decrease significantly with temperature after the crystallization operating temperature, for use in water salt systems, comprising the following steps in order:
1) starting a cold clear liquid of the initial prefabricated crystallization solution, wherein the temperature of the cold clear liquid is in a temperature interval with unobvious solubility trend;
2) the cold clear liquid passes through a heat exchanger with self-purification capacity at the flow velocity generating self-purification effect to be cooled into supercooled liquid in a temperature interval with unobvious solubility trend;
3) directly contacting and cooling the supercooled liquid and the continuously fed crystallization solution at a circulation ratio K to reach a preset crystallization operation temperature, generating supersaturation, crystallization, growth, sedimentation and collection of crystal slurry, and circulating a part of formed cold clear liquid in the step 2) and overflowing the rest of the formed cold clear liquid out of the system.
2. The continuous self-cooling crystallization method as claimed in claim 1, wherein the cold clear liquid overflowing the system uses a cold carrying medium torecover its cold for pre-cooling the crystallization solution for direct contact with the supercooled liquid for cooling crystallization.
3. The continuous self-cooling crystallization process as claimed in claim 1, wherein the pre-cooling serum is initially crystallized by cooling with intermittent partition walls during the start-up.
4. The continuous self-cooling crystallization method as claimed in claim 1, wherein the cold filtrate is returned to the system while the crystal slurry is collected to separate the solid crystals.
5. The continuous self-cooling crystallization method as claimed in claim 1 or 2, wherein the temperature of the cold supernatant is the crystallization operation temperature.
6. The continuous self-cooling crystallization process as claimed in claim 1 or 2, wherein the flow rate of the cold liquid to effect self-purification is 1-5M/S, and the circulation ratio K is 1-10.
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| WO2016190896A1 (en) * | 2015-05-22 | 2016-12-01 | Frosty Cold, Llc | Cooling agent for cold packs and food and beverage containers |
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| CN105329923B (en) * | 2015-11-17 | 2017-01-25 | 朱冲 | Crystallization process of magnesium method flue gas desulfurization by-product magnesium sulfate |
| CN108579118A (en) * | 2018-06-15 | 2018-09-28 | 成都丽雅纤维股份有限公司 | A kind of concentrated acid crystallization apparatus |
| CN114111437B (en) * | 2021-10-26 | 2024-07-26 | 湖南永杉锂业有限公司 | Heat exchanger scaling treatment system and control method thereof |
| CN117018665B (en) * | 2023-10-08 | 2023-12-26 | 长沙鑫本助剂有限公司 | Multistage cooling crystallization equipment for preparing triazole sodium salt |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1011149A1 (en) * | 1981-09-07 | 1983-04-15 | Всесоюзный научно-исследовательский и проектный институт галургии | Method of salt crystallization from solutions |
| JPS59199528A (en) * | 1983-04-26 | 1984-11-12 | Asahi Glass Co Ltd | Method for depositing ammonium chloride |
| US4547197A (en) * | 1982-12-23 | 1985-10-15 | Sulzer-Escher Wyss Ltd. | Treatment of brine elutriate |
| JPH03188904A (en) * | 1989-12-20 | 1991-08-16 | Toyo Eng Works Ltd | Pressurized freeze concentrator |
| JPH117802A (en) * | 1997-06-16 | 1999-01-12 | Kikuo Oya | Portable lighting apparatus |
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1996
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1011149A1 (en) * | 1981-09-07 | 1983-04-15 | Всесоюзный научно-исследовательский и проектный институт галургии | Method of salt crystallization from solutions |
| US4547197A (en) * | 1982-12-23 | 1985-10-15 | Sulzer-Escher Wyss Ltd. | Treatment of brine elutriate |
| JPS59199528A (en) * | 1983-04-26 | 1984-11-12 | Asahi Glass Co Ltd | Method for depositing ammonium chloride |
| JPH03188904A (en) * | 1989-12-20 | 1991-08-16 | Toyo Eng Works Ltd | Pressurized freeze concentrator |
| JPH117802A (en) * | 1997-06-16 | 1999-01-12 | Kikuo Oya | Portable lighting apparatus |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016190896A1 (en) * | 2015-05-22 | 2016-12-01 | Frosty Cold, Llc | Cooling agent for cold packs and food and beverage containers |
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