CA1335489C - Method for producing crystallisates out of solutions, more particularly salt-solutions, such as potassium-salt solutions, for example, by cold-crystallization - Google Patents
Method for producing crystallisates out of solutions, more particularly salt-solutions, such as potassium-salt solutions, for example, by cold-crystallizationInfo
- Publication number
- CA1335489C CA1335489C CA000607511A CA607511A CA1335489C CA 1335489 C CA1335489 C CA 1335489C CA 000607511 A CA000607511 A CA 000607511A CA 607511 A CA607511 A CA 607511A CA 1335489 C CA1335489 C CA 1335489C
- Authority
- CA
- Canada
- Prior art keywords
- solution
- crystallization chamber
- mother
- crystallization
- salt
- 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.)
- Expired - Fee Related
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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D9/00—Crystallisation
- B01D9/0004—Crystallisation cooling by heat exchange
- B01D9/0013—Crystallisation cooling by heat exchange by indirect heat exchange
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D9/00—Crystallisation
- B01D9/0036—Crystallisation on to a bed of product crystals; Seeding
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D9/00—Crystallisation
- B01D9/0059—General arrangements of crystallisation plant, e.g. flow sheets
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
- C01D3/00—Halides of sodium, potassium or alkali metals in general
- C01D3/22—Preparation in the form of granules, pieces, or other shaped products
- C01D3/24—Influencing the crystallisation process
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Saccharide Compounds (AREA)
Abstract
A description is given of a method for producing crystallizates of predetermined and uniform grain-size by cold-crystallization, whereby a concentration of dissolved salt is maintained constantly in the mother-liquor of a crystallization-suspension by continuous feeding of a saturated-salt solution and removal of heat, the said concentration being close to the supersolubility limit.
Description
~ SPECIFICATION 1 3 3 5 4 8 9 Part of the worldwide industrial crystallization of salts is crystallization from solutions in which supersaturation is produced and the crystallizate is removed by substantial elimination of this supersaturation.
Supersaturations may be produced in such salt-solutions for example by evaporating the solvent, by cooling the solutions, or by both measures.
A general review of the relevant prior art appears in "Chem.Ing.Techn." 50 (1978), pages 13-23 and in VDI-Berichte" No. 315 (1978), pages 26-36.
DD-PS 144 754, which deals with a method for crystallizing from supersaturated salt-solutions, also contains, in summarized form, criteria to be observed in crystalizing procedures. In any case, supersaturations are to be obtained first of all in the crystallizing solutions and the formation of crystal-nuclei is to be avoided as for as possible.
In all hitherto described methods, the supersaturation obtained in the crystallizing solutions is largely eliminated during crystal formation. Even if, according to previously known methods, this makes it possible to maintain conditions under which crystals of a specific grain-size preferably arise, the formation of considerable quantities of very fine, undersize or oversize crystals cannot be avoided.
8 -1- ~
It is therefore the purpose of the invention to provide a method for producing crystallizates from solutions, more particularly salt-solutions such a~ potassium-salt solution~, for example, by ~ool~g-crysta~iza~on, wherein increaaed crystal growth and a crystallizate of largely uniform grain-size may be obtained and may be regarded as a single-grain-size crystallizate.
According to the invention, there is provided a method for producing crystallizates from solutions, wherein a mixed solution is produced from a mother-liquor returned from a crystallization chamber and a freshly prepared solution, and wherein the mixed solution is cooled to produce a supersaturated mixed solution. That solution has a concentration greater than 1.5 times the Os~Nald-Miers width of the saturation-concentration in the crystallization chamber and is fed constantly to that chamber. Supersaturation is maintained substantially constant in the chamber by further removal of heat. The crystals produced are removed from the crystallization chamber. The concentration of the solution in the crystallization chamber is held in the upper half of the Os~wald-Miers range and the ratio of returned solution to freshly prepared solution is at least 2:1.
The advantage of this method is the rapid grain-sizes growth; moreover the resulting crystallizate is largely free of agglomeration and aggregation. This means that the product obt~ine~ with the method according to the invention is very pure since the individual crystals are largely free from contaminating inclusions.
~,~
1335~89 For the purpose of obtaining a crystal.lizate having crystals of equal grain-size, it has been found advantageous for the concentration of the solution, more particularly the mixed solution, to be more than 1.5 times, preferably between 2 and 2.5 times, the C~wald-~ers width of the saturation concentration in the crystall.izer. This means that the concentration of the solution, more particularly of the mixed solution, in the crystall.izing chamber is held in the upper half of the Os~wald-Miers area.
The method according to the invention prevents elimination of the supersaturation in the fluid phase of the crystallization-suspension and, according to the invention, the concentration of the mother-liquor is always held at the supersolubility limit so that elimination of supersaturation, effected by crystallization in the mother-liquor, is compensated for.
The term "Oshwald-Miers area", in the solution-diagram of each sait, signifies the area bounded by the solubility-curve and the supersolubility-curve.
The Os~wald-Miers area characterizes a metastable condition where no primary crystallization nuclei arise ln spite of supersaturation of the solution. Only when the upper limit of the Os~wald-Miers area or of the supersolubil.ity-curve is exceeded is there a very rapid increase in the rate of formation of spontaneously arising crystallization nuclei.
~,, Supersaturation of the solution, more particularly of the mixed sol.ution, may be effected, with advantage, by cooling, preferably by surface cooling.
In order that supersaturation may be maintained in Sthe crystallizing chamber at the upper limit of the Oshwald-Miers area, according to another characteristic of the invention, the supersaturated solution, preferably obtained by cooling, is fed to, and is rapidly mixed with, the crystallization-suspension hel.d in suspension.
10In order to achieve uniform distribution as quickly as possible, a guide-tube with an agitator is arranged in the crystallizing chamber, thus providing a vertical circulating flow.
According to still another characteristic of the lS invention, the mother-liquor constantly discharged from the crystall.izing chamber is divided into a larger amount of solution and a small.er amount of sol.ution, and the smaller amount is heated. This dissolves the very fine salt carried along and this solution is mixed with the initial salt, thus producing a saturated initial sol.ution which is fed to the mixing container. The larger amount of solution, discharged from the crystallizing chamber, is also fed to the mixing container in order to produce a mixed solution.
The small.er amount of solution amounts to less than 1/3, preferabl.y less than lfS, of the total amount of mother-liquor.
The apparatus for implementation of the method is shown diagrammaticall.y in the drawing.
In the said drawing, K indicates the crystallizing chamber (crystallizer), the crystallizate being removed therefrom through line 9.
A saturated initial solution is produced in initial-solution-container L to which salt is fed through line 11 and the smaller amount of mother-liquor solution through line 2 after passing through heat-exchanger E, the solution having been converted into an unsaturated condition by the increase in temperature. The smaller amount of solution 7 shoul.d be less than 1/3, preferably less than 1/5, of the total amount of clarified mother-liquor removed from crystallizing chamber K through line 6.
The saturated solution in container L at a predetermined temperature passes through line 1 into mixing vessel B with the larger amount of clarified mother-liquor arriving from crystallizing chamber K through line 3. The mixed solution contained in mixing vessel B is then passed through line 4 to cooler C in which the mixed solution is cooled to a temperature in the metastable supersaturation range.
The cooler used is preferably a surface cooler. The supersaturated mixed solution thus obtained is then fed through line 5 into crystallizing chamber K and is quickly mixed with the crystallization-suspension. This l.argely compensates for the elimination of supersaturation completed in the fluid phase of the crystallization suspension and a considerable supersaturation is maintained. This makes a high crystallization velocity possible.
The danger of increased formation of nuclei hitherto occurring with such considerable supersaturation is eliminated, with the method according to the invention, by the high mixing speed of the solution introduced into crystallizing chamber K through line 3. In order to improve this still further, crystallizing chamber K contains a guide-tube F having an agitator R which produces a vertically directed flow.
The crystals, which have now grown to the desired grain-size, are removed from crystallizing chamber K through line 9. They may be washed and dried to make useful products.
Any fine crysta]s produced are removed with the mother-liquor, through line 6, from crystallizing chamber K
and are redissolved in the remainder of the circuit, as described hereinbefore.
It may be advantageous to increase the efficiency of the method according to the invention by additional cooling of the crystallization-suspension in crystallizing chamber K by providing cooling through adiabatic evaporation.
According to the method of the invention it is possible to obtain more than 90% of crystals of a desired grain-size in high space/time yield. Only relatively small amounts of over- and under-size crystals are present.
Example 1 1335489 In the case of the apparatus shown in Fig. 1 for the implementation of the method, use is made of a crystallizer K with a volume of 15 1. The flow needed to obtain the suspension condition of the crystals in the crystallizer is produced by an agitator R which provides a downwardly directed flow in guide-tube Rl.
This guide-tube is surrounded by a cooling jacket M
which provides additional cooling of the crystallization-suspension.
A solution saturated at a temperature of 72 C is prepared, with an average throughput of 110 l/h, from the mother-liquor fed through line 2 and the potassium-sulphate fed through line 11. This solution is mixed in container 8, which has a volume of 25 1, with about 320 l/h of a potassium-sulphate solution which is supplied from crystallizing chamber K through lines 6 and 3. The temperature in the mixing container is set at 56C. It passes through line 4 to heat-exchanger C where the temperature of the mixture is lowered to 52C.
_ At this temperature, the now supersaturated solution is fed to crystallizing chamber K where a temperature of 48C is maintained.
Crystallizer K is inoculated with 20 g of seed (grain-size between 0.10 and 0.`16 mm). The resulting crystallizate is discharged after 4 hours, is washed with a 133s489 methanol-water mixture, is dried at 110C, and is weighed.
The crystallizate-mass amounts to 11.5 kg of potassium-sulphate having the following grain-size distribution:
GRAIN-SIZE WEIGHT
in mm in %
+ 1,60 1,0 + 1,25 66,2 + 1,00 31,5 + 0,80 1,0 - 0,80 0'3 Total: 100,0 Example 2 In a procedure according to Fig. 1, potassium-chloride is crystallized. Because of its great solubility and very narrow Os~wald-~ers area, this can be crystallized only under extremely adverse conditions.
A saturated solution is produced, at a~ 3average `~ throughput of 100 l/h, in container L, from the mother-liquor and the potassium-chloride, at a temperature of 46C. This solution is mixed, in container B, with 1000 l/h of mother-liquor from the crystallizer. This mixture, at a temperature of 41C, is cooled in heat-exchanger C to a temperature of 40.5C and is then introduced into crystallizing chamber K where a temperature of 40C is maintained.
The crystallizer is inoculated with 20 kg of seed (grain-size between 0.10 and 0.16 mm). The crystallizate obtained after two hours is discharged, is washed with a methanol-water mixture, and is dried at 110C. The crystallizate amounts to 2.1 kg of potassium-chloride having the following grain-size distribution:
GRAIN-SIZE WEIGHT
in mm in %
20 + 1,00 2,6 + 0,80 41,4 + 0,63 26,8 + 0,56 9~0 + 0,50 7,4 25 + 0,43 5,3 + 0,40 4,4 - 0,40 3,1 Total:100,0
Supersaturations may be produced in such salt-solutions for example by evaporating the solvent, by cooling the solutions, or by both measures.
A general review of the relevant prior art appears in "Chem.Ing.Techn." 50 (1978), pages 13-23 and in VDI-Berichte" No. 315 (1978), pages 26-36.
DD-PS 144 754, which deals with a method for crystallizing from supersaturated salt-solutions, also contains, in summarized form, criteria to be observed in crystalizing procedures. In any case, supersaturations are to be obtained first of all in the crystallizing solutions and the formation of crystal-nuclei is to be avoided as for as possible.
In all hitherto described methods, the supersaturation obtained in the crystallizing solutions is largely eliminated during crystal formation. Even if, according to previously known methods, this makes it possible to maintain conditions under which crystals of a specific grain-size preferably arise, the formation of considerable quantities of very fine, undersize or oversize crystals cannot be avoided.
8 -1- ~
It is therefore the purpose of the invention to provide a method for producing crystallizates from solutions, more particularly salt-solutions such a~ potassium-salt solution~, for example, by ~ool~g-crysta~iza~on, wherein increaaed crystal growth and a crystallizate of largely uniform grain-size may be obtained and may be regarded as a single-grain-size crystallizate.
According to the invention, there is provided a method for producing crystallizates from solutions, wherein a mixed solution is produced from a mother-liquor returned from a crystallization chamber and a freshly prepared solution, and wherein the mixed solution is cooled to produce a supersaturated mixed solution. That solution has a concentration greater than 1.5 times the Os~Nald-Miers width of the saturation-concentration in the crystallization chamber and is fed constantly to that chamber. Supersaturation is maintained substantially constant in the chamber by further removal of heat. The crystals produced are removed from the crystallization chamber. The concentration of the solution in the crystallization chamber is held in the upper half of the Os~wald-Miers range and the ratio of returned solution to freshly prepared solution is at least 2:1.
The advantage of this method is the rapid grain-sizes growth; moreover the resulting crystallizate is largely free of agglomeration and aggregation. This means that the product obt~ine~ with the method according to the invention is very pure since the individual crystals are largely free from contaminating inclusions.
~,~
1335~89 For the purpose of obtaining a crystal.lizate having crystals of equal grain-size, it has been found advantageous for the concentration of the solution, more particularly the mixed solution, to be more than 1.5 times, preferably between 2 and 2.5 times, the C~wald-~ers width of the saturation concentration in the crystall.izer. This means that the concentration of the solution, more particularly of the mixed solution, in the crystall.izing chamber is held in the upper half of the Os~wald-Miers area.
The method according to the invention prevents elimination of the supersaturation in the fluid phase of the crystallization-suspension and, according to the invention, the concentration of the mother-liquor is always held at the supersolubility limit so that elimination of supersaturation, effected by crystallization in the mother-liquor, is compensated for.
The term "Oshwald-Miers area", in the solution-diagram of each sait, signifies the area bounded by the solubility-curve and the supersolubility-curve.
The Os~wald-Miers area characterizes a metastable condition where no primary crystallization nuclei arise ln spite of supersaturation of the solution. Only when the upper limit of the Os~wald-Miers area or of the supersolubil.ity-curve is exceeded is there a very rapid increase in the rate of formation of spontaneously arising crystallization nuclei.
~,, Supersaturation of the solution, more particularly of the mixed sol.ution, may be effected, with advantage, by cooling, preferably by surface cooling.
In order that supersaturation may be maintained in Sthe crystallizing chamber at the upper limit of the Oshwald-Miers area, according to another characteristic of the invention, the supersaturated solution, preferably obtained by cooling, is fed to, and is rapidly mixed with, the crystallization-suspension hel.d in suspension.
10In order to achieve uniform distribution as quickly as possible, a guide-tube with an agitator is arranged in the crystallizing chamber, thus providing a vertical circulating flow.
According to still another characteristic of the lS invention, the mother-liquor constantly discharged from the crystall.izing chamber is divided into a larger amount of solution and a small.er amount of sol.ution, and the smaller amount is heated. This dissolves the very fine salt carried along and this solution is mixed with the initial salt, thus producing a saturated initial sol.ution which is fed to the mixing container. The larger amount of solution, discharged from the crystallizing chamber, is also fed to the mixing container in order to produce a mixed solution.
The small.er amount of solution amounts to less than 1/3, preferabl.y less than lfS, of the total amount of mother-liquor.
The apparatus for implementation of the method is shown diagrammaticall.y in the drawing.
In the said drawing, K indicates the crystallizing chamber (crystallizer), the crystallizate being removed therefrom through line 9.
A saturated initial solution is produced in initial-solution-container L to which salt is fed through line 11 and the smaller amount of mother-liquor solution through line 2 after passing through heat-exchanger E, the solution having been converted into an unsaturated condition by the increase in temperature. The smaller amount of solution 7 shoul.d be less than 1/3, preferably less than 1/5, of the total amount of clarified mother-liquor removed from crystallizing chamber K through line 6.
The saturated solution in container L at a predetermined temperature passes through line 1 into mixing vessel B with the larger amount of clarified mother-liquor arriving from crystallizing chamber K through line 3. The mixed solution contained in mixing vessel B is then passed through line 4 to cooler C in which the mixed solution is cooled to a temperature in the metastable supersaturation range.
The cooler used is preferably a surface cooler. The supersaturated mixed solution thus obtained is then fed through line 5 into crystallizing chamber K and is quickly mixed with the crystallization-suspension. This l.argely compensates for the elimination of supersaturation completed in the fluid phase of the crystallization suspension and a considerable supersaturation is maintained. This makes a high crystallization velocity possible.
The danger of increased formation of nuclei hitherto occurring with such considerable supersaturation is eliminated, with the method according to the invention, by the high mixing speed of the solution introduced into crystallizing chamber K through line 3. In order to improve this still further, crystallizing chamber K contains a guide-tube F having an agitator R which produces a vertically directed flow.
The crystals, which have now grown to the desired grain-size, are removed from crystallizing chamber K through line 9. They may be washed and dried to make useful products.
Any fine crysta]s produced are removed with the mother-liquor, through line 6, from crystallizing chamber K
and are redissolved in the remainder of the circuit, as described hereinbefore.
It may be advantageous to increase the efficiency of the method according to the invention by additional cooling of the crystallization-suspension in crystallizing chamber K by providing cooling through adiabatic evaporation.
According to the method of the invention it is possible to obtain more than 90% of crystals of a desired grain-size in high space/time yield. Only relatively small amounts of over- and under-size crystals are present.
Example 1 1335489 In the case of the apparatus shown in Fig. 1 for the implementation of the method, use is made of a crystallizer K with a volume of 15 1. The flow needed to obtain the suspension condition of the crystals in the crystallizer is produced by an agitator R which provides a downwardly directed flow in guide-tube Rl.
This guide-tube is surrounded by a cooling jacket M
which provides additional cooling of the crystallization-suspension.
A solution saturated at a temperature of 72 C is prepared, with an average throughput of 110 l/h, from the mother-liquor fed through line 2 and the potassium-sulphate fed through line 11. This solution is mixed in container 8, which has a volume of 25 1, with about 320 l/h of a potassium-sulphate solution which is supplied from crystallizing chamber K through lines 6 and 3. The temperature in the mixing container is set at 56C. It passes through line 4 to heat-exchanger C where the temperature of the mixture is lowered to 52C.
_ At this temperature, the now supersaturated solution is fed to crystallizing chamber K where a temperature of 48C is maintained.
Crystallizer K is inoculated with 20 g of seed (grain-size between 0.10 and 0.`16 mm). The resulting crystallizate is discharged after 4 hours, is washed with a 133s489 methanol-water mixture, is dried at 110C, and is weighed.
The crystallizate-mass amounts to 11.5 kg of potassium-sulphate having the following grain-size distribution:
GRAIN-SIZE WEIGHT
in mm in %
+ 1,60 1,0 + 1,25 66,2 + 1,00 31,5 + 0,80 1,0 - 0,80 0'3 Total: 100,0 Example 2 In a procedure according to Fig. 1, potassium-chloride is crystallized. Because of its great solubility and very narrow Os~wald-~ers area, this can be crystallized only under extremely adverse conditions.
A saturated solution is produced, at a~ 3average `~ throughput of 100 l/h, in container L, from the mother-liquor and the potassium-chloride, at a temperature of 46C. This solution is mixed, in container B, with 1000 l/h of mother-liquor from the crystallizer. This mixture, at a temperature of 41C, is cooled in heat-exchanger C to a temperature of 40.5C and is then introduced into crystallizing chamber K where a temperature of 40C is maintained.
The crystallizer is inoculated with 20 kg of seed (grain-size between 0.10 and 0.16 mm). The crystallizate obtained after two hours is discharged, is washed with a methanol-water mixture, and is dried at 110C. The crystallizate amounts to 2.1 kg of potassium-chloride having the following grain-size distribution:
GRAIN-SIZE WEIGHT
in mm in %
20 + 1,00 2,6 + 0,80 41,4 + 0,63 26,8 + 0,56 9~0 + 0,50 7,4 25 + 0,43 5,3 + 0,40 4,4 - 0,40 3,1 Total:100,0
Claims (12)
1. A method for producing crystallizates from solutions, wherein a mixed solution is produced from a mother-liquor returned from a crystallization chamber and a freshly prepared solution, and wherein the mixed solution is cooled to produce a supersaturated mixed solution characterized in that the supersaturated mixed solution has a concentration greater than 1.5 times the Ostwald-Miers width of the saturation-concentration in the crystallization chamber and is fed constantly to said chamber, in that supersaturation is maintained substantially constant in the crystallization chamber by further removal of heat, and in that the crystals arising are removed from the crystallization chamber, the concentration of the solution in the crystallization chamber being held in the upper half of the Ostwald-Miers range, and the ratio of returned solution to freshly prepared solution being at least 2:1.
2. A method according to Claim 1, characterized in that the mixed solution has a concentration in excess of at least 2 to 2.5 times the Ostwald-Miers width of the saturation-concentration in the crystallization chamber.
3. A method according to Claim 1, characterized in that the concentration of the solution in the crystallization chamber is adjusted close to the supersolubility limit.
4. A method according to Claim 1, characterized in that the ratio of returned mother-liquor to freshly prepared solution is greater than 3:1.
5. A method according to Claim 1, characterized in that mother-liquor is constantly discharged from the crystallization chamber and is divided into a larger amount of solution and a smaller amount of solution, and in that the smaller amount of solution is heated and mixed with a salt to produce a saturated initial solution which comprises said freshly prepared solution, the smaller amount of solution amounting to less than 1/3 of the total amount of mother-liquor discharged from the crystallization chamber.
6. A method according to Claim 5, characterized in that the smaller amount of solution amounts to less than 1/5 of the total amount of mother-liquor discharged from the crystallization chamber.
7. A method according to Claim 5, characterized in that the larger amount of mother-liquor discharged from the crystallization chamber is mixed with said freshly prepared solution to produce said mixed solution.
8. A method according to Claim 5, characterized in that the said smaller amount of solution is heated to produce an unsaturated solution which is fed to a dissolving container, to which a salt is fed in order to produce a saturated initial solution comprising said freshly prepared solution.
9. A method according to Claim 1, characterized in that the desired temperature and supersaturation is obtained in the crystallization chamber by additional cooling.
10. A method according to Claim 1, characterized in that the solution is a salt solution.
11. A method according to Claim 1, characterized in that the solution is a potassium salt solution.
12
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3831305.7 | 1988-09-15 | ||
| DE3831305A DE3831305A1 (en) | 1988-09-15 | 1988-09-15 | Process for the preparation of crystals from solutions, in particular salt solutions, such as for example potassium salt solutions, by cold crystallisation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1335489C true CA1335489C (en) | 1995-05-09 |
Family
ID=6362963
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000607511A Expired - Fee Related CA1335489C (en) | 1988-09-15 | 1989-08-03 | Method for producing crystallisates out of solutions, more particularly salt-solutions, such as potassium-salt solutions, for example, by cold-crystallization |
Country Status (4)
| Country | Link |
|---|---|
| CA (1) | CA1335489C (en) |
| DD (1) | DD284606A5 (en) |
| DE (1) | DE3831305A1 (en) |
| IL (1) | IL91403A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19844227C2 (en) * | 1998-09-26 | 2002-04-18 | Daimler Chrysler Ag | Method and device for producing crystals from supersaturated solutions |
| DE102016101217A1 (en) | 2016-01-25 | 2017-07-27 | Bma Braunschweigische Maschinenbauanstalt Ag | Process for recovering crystals from a mother liquor and suitable crystallizer |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1619777A1 (en) * | 1967-08-26 | 1970-12-03 | Rudolph Koepp & Co Chem Fab Ag | Device and method for the continuous separation of crystalline substances from solutions |
| DE1903447A1 (en) * | 1968-01-29 | 1969-08-28 | Yoshio Aoyama | Process for controlling the crystal size in continuous crystallization |
-
1988
- 1988-09-15 DE DE3831305A patent/DE3831305A1/en active Granted
-
1989
- 1989-08-03 CA CA000607511A patent/CA1335489C/en not_active Expired - Fee Related
- 1989-08-24 IL IL9140389A patent/IL91403A/en not_active IP Right Cessation
- 1989-09-13 DD DD89332600A patent/DD284606A5/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| DE3831305C2 (en) | 1993-08-05 |
| IL91403A (en) | 1994-08-26 |
| DE3831305A1 (en) | 1990-03-22 |
| IL91403A0 (en) | 1990-04-29 |
| DD284606A5 (en) | 1990-11-21 |
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