GB2053881A - Process for producing potassium sulphate - Google Patents
Process for producing potassium sulphate Download PDFInfo
- Publication number
- GB2053881A GB2053881A GB8023793A GB8023793A GB2053881A GB 2053881 A GB2053881 A GB 2053881A GB 8023793 A GB8023793 A GB 8023793A GB 8023793 A GB8023793 A GB 8023793A GB 2053881 A GB2053881 A GB 2053881A
- Authority
- GB
- United Kingdom
- Prior art keywords
- potassium
- reaction
- sulphate
- temperature
- reactor
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 32
- OTYBMLCTZGSZBG-UHFFFAOYSA-L potassium sulfate Chemical compound [K+].[K+].[O-]S([O-])(=O)=O OTYBMLCTZGSZBG-UHFFFAOYSA-L 0.000 title claims abstract description 19
- 229910052939 potassium sulfate Inorganic materials 0.000 title claims abstract description 19
- 239000001120 potassium sulphate Substances 0.000 title claims description 33
- 235000011151 potassium sulphates Nutrition 0.000 title claims description 17
- 238000006243 chemical reaction Methods 0.000 claims abstract description 50
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 30
- 235000011149 sulphuric acid Nutrition 0.000 claims abstract description 30
- CHKVPAROMQMJNQ-UHFFFAOYSA-M potassium bisulfate Chemical compound [K+].OS([O-])(=O)=O CHKVPAROMQMJNQ-UHFFFAOYSA-M 0.000 claims abstract description 19
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 claims description 62
- 239000001103 potassium chloride Substances 0.000 claims description 31
- 235000011164 potassium chloride Nutrition 0.000 claims description 31
- 239000001117 sulphuric acid Substances 0.000 claims description 25
- 239000007795 chemical reaction product Substances 0.000 claims description 20
- 239000000047 product Substances 0.000 claims description 11
- 238000002156 mixing Methods 0.000 claims description 5
- 230000015572 biosynthetic process Effects 0.000 claims description 4
- 239000000376 reactant Substances 0.000 claims description 2
- 229910000343 potassium bisulfate Inorganic materials 0.000 abstract description 3
- 230000007774 longterm Effects 0.000 abstract description 2
- 238000003756 stirring Methods 0.000 abstract description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 13
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 11
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 11
- 150000003839 salts Chemical class 0.000 description 10
- 239000011541 reaction mixture Substances 0.000 description 7
- 239000000460 chlorine Substances 0.000 description 6
- 238000001816 cooling Methods 0.000 description 5
- 230000014759 maintenance of location Effects 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 229910052801 chlorine Inorganic materials 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 229910001514 alkali metal chloride Inorganic materials 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000010924 continuous production Methods 0.000 description 3
- 238000005755 formation reaction Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- 239000011473 acid brick Substances 0.000 description 2
- 238000010923 batch production Methods 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 230000002950 deficient Effects 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 229910052936 alkali metal sulfate Inorganic materials 0.000 description 1
- 239000011449 brick Substances 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000003337 fertilizer Substances 0.000 description 1
- 230000009969 flowable effect Effects 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 239000012768 molten material Substances 0.000 description 1
- WVULZDFWPQCPPJ-UHFFFAOYSA-N potassium;hydrochloride Chemical compound Cl.[K] WVULZDFWPQCPPJ-UHFFFAOYSA-N 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000003746 solid phase reaction Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
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
- C01D5/02—Preparation of sulfates from alkali metal salts and sulfuric acid or bisulfates; Preparation of bisulfates
Abstract
K2SO4 is produced by reacting KCl with H2SO4 using 2.0 to 2.2 mols of KCl per mol of H2SO4 with stirring at from room temperature to 100 DEG C, and the resulting KHSO4 is reacted e.g. in a muffle furnace with unreacted KCl at 300 DEG to 400 DEG C. By this two- step process, overall reaction can be carried out at lower temperature and in shorter time, and long term continuous operation is possible.
Description
SPECIFICATION
Process for producing potassium sulphate
This invention relates to a process for producing potassium sulphate from potassium chloride and sulphuric acid.
A process of reacting 2 mols of potassium chloride with one mol of sulphuric acid to obtain potassium sulphate with recovery of hydrogen chloride evolved has been commercially operated. When this reaction is carried out in dry manner, it is separated into the following two steps.
First step:
KCI + H2SO4 = KHSO4 + HCI + 3KCal (1)
Second step:
KHSO4 + KCI = K2SO4 + KCI -- 17KCal (2)
The first step reaction proceeds even at a relatively low temperature such as room temperature to 10000, but a considerably high temperature such as 3000C to 50000 is necessary for advancing the second step reaction to a substantial extent. Thus, although the reactions of the first and second steps can be carried out in the same reactor it is regarded as preferable and efficient particularly for a continuous production process to separate the two steps into a first step carried out in a reactor and a second step carried out in a reaction furnace thereby to substantially alleviate the load on the reaction furnace for the second step.
Thus, Japanese patent publications No. 756/1 957 discloses a process of carrying out the reaction in two steps wherein separate reactors are employed in the respective steps. The gist of the process is as follows: a process for producing alkali metal sulphates and hydrogen chloride gas from alkali metal chlorides and sulphuric acid which consists of a first step of feeding into a reactor, an alkali metal chloride and sulphuric acid in such amounts that an acid salt containing 35% or less of a normal salt is prepared, and maintaining the reaction temperature at a temperature at which the resulting material is molten, and a second step of feeding a deficient amount of the alkali metal chloride necessary for preparing the normal salt, to the molten material to complete the formation reaction of the normal salt.
According to the process, however, problems with respect to operation and corrosion have been reaised. Namely, in the first step, a temperature of 2000 to 2500C is required for forming 35% or less of the normal salt, while, in the case where the acid salt is potassium hydrogen sulphate, it melts at about 21000; hence agitation is difficult as compared with the case where they are mixed together both in the form of powder. Further, in order to withstand hydrogen chloride evolved at such a temperature, it is necessary to employ e.g. acid resistant brick as the material for the reactor, and also in order to maintain the reaction, external heating is necessary. In addition, since a solid phase reaction is carried out at 4000C or higher in the second step, heat conduction is so poor that a high temperature and long period of treatment is compelled.
The above-mentioned problems of the Japanese patent publication No. 756/1 957 have been partly solved by a process disclosed in Japanese patent publication No. 2,666/1 957. Namely, according to the later process, an acid salt containing 45% or less of a normal salt is formed in the reactor of the first step, and is cooled to solidify it, followed by fine pulverization. Thereafter, a deficient amount of the chloride necessary for preparing the normal salt is added thereto, and they are uniformly mixed together and then fed to the reactor of the second step, whereby the time required at 3000 to 5000 is shortened, for example 6 hours to 3 hours. However, even when the process of Japanese patent publication No.
2666/1957 is employed, the problem that such a high temperature as 2500C is required in the reactor of the first step cannot be overcome, and also the process of Japanese patent publication No.
2666/1 977 has a disadvantage that steps of cooling and mill-mixing the reaction product of the first step are newly added.
The present inventors have made studies through practical operations for many years on the technical problems with regard to the production process of potassium sulphate, and as a result the following process has been found:
Sulphuric acid and potassium chloride in a molar ratio corresponding to 1 mol of sulphuric acid and 2.0 to 2.2 mols of potassium chloride are first subjected to the above-mentioned reaction of the first step i.e. formation of potassium hydrogen sulphate, at a temperature of room temperature to 1000C in the form of powder as it is, and thereafter a mixture of potassium hydrogen sulphate as the resulting product with unreacted potassium chloride is reacted together at a temperature of 3000 to 4000C in a reaction furnace of the second step.
At that time, by employing a muffle furnace as a reaction furnace of the second step, and also by carrying out feed of the raw materials and withdrawal of the reaction product in an adequate manner, the problem of melting and corrosion brought about by the high temperature of the first step as well as the problem of the life of the furnace brought about by the necessity of a long retention time at high temperature in the second step, have been both solved.
Thus, the present invention can provide a dry process for producing potassium sulphate by way of a new two-step method. When mixing with stirring is well effected, the reaction can be completed in a shorter time compared to the known processes.
The present invention accordingly resides in:a batch process or continuous process for producing potassium sulphate, optionally as a mixture thereof with a small amount of unreacted potassium chloride, by reacting potassium chloride with sulphuric acid, which process comprises: (1) reacting potassoim chloride and sulphuric acid using 2.0 to 2.2 mols of potassium chloride per one mol of sulphuric acid under mixing at a temperature of room temperature (say 1 5 or 200C) to 10000, thereby to form potassium hydrogen sulphate, and then (2) reacting the potassium hydrogen sulphate with unreacted potassium chloride at a temperature of 3000 to 4000C to produce potassium sulphate.
The present invention further resides in the following preferred processes: a process as defined wherein the formation of potassium hydrogen sulphate is continuously carried out in a first step reactor and thatof potassium sulphate is continuously carried out in a second step reactor; a process as defined wherein the reactor of the second step is a muffle furnace whose upper half surface alone is arranged to be heated; a process as defined wherein the reaction product of the second step is recovered by overflow.
Aspects of the present invention are discussed as follows: (a) Reaction of the first step in the first step reactor
As is seen in the above-mentioned equation of the reaction of the first step, one mol of potassium chloride and one mol of sulphuric acid yield one mol of potassium hydrogen sulphate and one mol of hydrogen chloride. However, in the present invention, sulphuric acid (typically 98%) and potassium chloride are employed in a proportion of one mol of the former to 2.0 to 2.2 mols of the latter, and potassium chloride to be reacted in the second step is mixed in advance in the first step.The reaction temperature for the first step is in the range of room temperature to 1000C, and the reactor employed may be any made of a material resistant to sulphuric acid and dry hydrogen chloride at the reaction temperature: no special material such as acid resistant brick is required due to the low reaction temperature. Further, it is preferable to employ an agitator e.g. paddle or ribbon agitator (preferably equipped with double or high multiple shafts) suitable for mixing powder (potassium chloride, etc.) with liquid (sulphuric acid). As for the type of the reaction vessel, either a vertical type or horizontal type may be employed.The reaction of the first step in the process of the present invention usually proceeds smoothly and rapidly even at the temperature of room temperature to 1000C, due to the presence of excess potassium chloride. Since only a small amount of unreacted sulphuric acid is likely to be present in the reaction product, this product is a flowable powder; hence it is easy to transfer the product into the reactor of the second step. On the other hand, evolved hydrogen chloride can be sent to an apparatus for producing concentrated hydrochloric acid, the gas concentration being in the range of 40 to 60 S by volume but varying depending on the operational conditions.The retention time in the reactor of the first step may suitably be in the range of 30 minutes to 3 hours, preferably in the range of 30 minutes to one hour, both in the case of a batch process and in the case of a continuous process.
(b) Reaction of the second step in the second step reactor.
As is seen in the equation of the reaction of the second step, one mol of potassium hydrogen sulphate and one mol of potassium chloride theoretically yield one mol of potassium sulphate and one mol of hydrogen chloride. However, in the process of the present invention, the amount of potassium chloride fed into the reactor of the first step is in the range of 2.0 to 2.2 mols per mol of sulphuric acid. If the amount exceeds 2 mols, the resulting product is a mixture of potassium sulphate with potassium chloride, with potassium chloride helping to prevent unreacted potassium hydrogen sulphate from discharging in molten state and thereby facilitating the transfer of the reaction product after the reaction of the second step.On the other hand, even when the equimolecular reaction of the present invention (i.e. amount of KC1,2.0 mols; amount of H2S04, 1 mol) is carried out, the presence of unreacted potassium chloride corresponding to the presence of potassium hydrogen chloride as an intermediate in the product contained in the reactor of the second step, makes it possible notably to reduce the surface tackiness of the reaction product. The reaction of the second step is a reaction between a solid (KCI) and a melt (KHSO2) and yet is an endothermic reaction. Thus, unless the mutual contact and heating (and hence heat transfer) of the reactants are sufficient, it is impossible to improve the conversion and shorten the reaction time (retention time). Further, in the case of continuous reaction, steps should particularly be taken to prevent an unreacted portion of the reaction mixture (where reaction has not yet advanced sufficiently) from discharge in a short-circuit manner. Now the present inventors have found that (i) a muffle furnace capable of heating the reaction mixture from its upper surface alone is surprisingly more suitable for the present process than a tubular furnace capable of heating the reaction mixture from its total periphery. Further the present inventors have also found that (ii) the abovementioned discharge in short-circuit manner can be prevented using discharge of the reaction product of the second step by overflow.The reason for the above item (i) is presumed to be in that, in the case of a tubular furnace, molten potassium hydrogen sulphate is more liable to adhere to the surface of the lower half of the furnace. At any rate, heat transfer is poor on the surface of the lower half of the furnace. The reason for the above item (ii) is presumed to be in that, in the case of overflow, a portion of the reaction mixture containing a smaller amount of melt is more liable to be smoothly discharged.
These items (i) and (ii) do not emerge from the above-mentioned Japanese patent publication Nos.
756/1957 and 2666/1 957 wherein a tubular furnace was principally employed (in addition, see
Japanese patent publication No. 10153/1959). Further, according to these prior art inventions, the reaction of the first step is so adjusted as to contain 35% to 45% of a normal salt (potassium sulphate) thereby to reduce the substantial load on the reaction furnace of the second step. In this respect, it is clear that the techniques of these inventions are different from the process of the present invention.
As a result, in the case of the Japanese patent publication No. 2666/1 957, the residual percentage of chlorine is 2.4 to 1.6% by weight at 3000 to 4000C in one hour, whereas according to the present invention, it is possible to attain conversions to the same extent after completion of the reaction of the second step, without passing through steps of cooling, solidification and fine milling between the first step and the second step.
(c) Quenching of the reaction product discharge from the second step reactor
The reaction product usually has a temperature of about 3000 to 3700C, and depending on the reaction conditions, it still contains about 1.5 to 2.5% by weight of chlorine and also about 2.0 to 3.0% by weight of sulphuric acid. Thus, when the product is used as potassium sulphate for fertilizers or other industries, it is necessary to neutralize the product with lime or the like in a separate step, and also the product must be cooled down to a suitable temperature such as room temperature to 2000 C, for its transfer. According to an embodiment of the present invention, it is possible partly to cool the discharged product by scattering or dropwise adding a small amount of water thereon.The scattering or dropwise adding of water is carried out to such an extent that its temperature is elevated by the sensible heat of the reaction product of the second step discharged by overflow whereby it is vaporized, in a cooler or a transfer vessel for the product. More concretely, for example, 40 to 60 Kg of water is scattered on 1 ,000 Kg of the mixture at 3000 C. When the temperature of the reaction product is reduced down to 1000C or lower by the water, it becomes impossible to vaporize the scattered water, and hence subsequent cooling is carried out by heat transfer or air cooling.
In summary, due to the low reaction temperature in the first step reactor, the carrying out of the reaction of the first step and transfer and supply of the resulting reaction product to the second step reactor are very easy. This is brought about by the fact that no melt of potassium hydrogen sulphate is formed in the reactor of the first step. Carrying out of the reaction of the second step in the reactor of the second step and continuous discharge of the resulting reaction product are very easy, and also it is possible to complete the reaction at a relatively low temperature such as 3000 to 4000C, and in a reaction time as short as one hour. This is presumed to be brought about by the following facts.
(a) In the case where the amount of potassium chloride is in a small excess to that of sulphuric acid in such a manner the molar ratio by mol of potassium chloride to sulphuric acid as raw materials employed is more than 2.0 and not more than 2.2, the molar ratio of unreacted potassium hydrogen sulphate to unreacted potassium chloride becomes less with the progress of the reaction in the reactor of the second step, whereby the amount of unreacted KSO4 can be rapidly reduced down to a definite value.
(b) Further, in the case of a ratio of sulphuric acid/potassium chloride of 2.0, too, the reaction mixture of the first step (potassium hydrogen sulphate plus potassium chloride) in a very good finely mixed state is supplied to the reactor of the second step, whereby the amount of the reaction mixture discharge in a short-circuit manner is extremely small.
Since the reaction temperature in the reactor of the second step is not required to be as high a temperature as 4000 to 5000 C, the loss of heat resistant bricks on the surface of radiation heat muffle furance is less (not: the temperature inside the flue of muffle furnace is 11000 to 1 2000 C), which makes possible long term operation, as long as one to three years. Further, since the heat transfer area per unit volume may be small, it is easy to make the capacity larger than a tubular furnace.
The present invention will be further illustrated by way of a non-limiting Example. A Comparison
Example is also given.
EXAMPLE 1
Into a first step reactor of closed and horizontal type equipped with an agitator were continuously fed 163 kg/hr of 96% potassium chloride and 100 kg/hr of 98% sulphuric acid (molar ratio KCI :H2SO4 is 2:1:1, and the reaction temperature was maintained at 600 to 700C by cooling. In order to prevent evolved hydrogen chloride gas from dissipating to the atmosphere, the pressure inside the reactor was maintained under a slight reduced pressure of -5 to -10 mm water-gauge and 40.3 Nm3/hr of hydrogen chloride having a concentration of 50% by volume was collected.
The reaction product of the first step was continuously fed in toto to a reactor of the second step.
(muffle furnace) whose upper half surface alone was heated by radiation and which was equipped with a double-shaft agitator.
The reaction product of the first step was fed into the muffle furnace at a location between the central part and the raw material-feeding port of the furnace and close to this feeding port; the temperature of the reaction mixture in the furnace was maintained at 3500C; and the retention time was one hour. The pressure inside the reactor of the second step was maintained at O to -5mm water-gauge. As a result, 39.6 Nm3/hr of hydrogen chloride having a concentration of 60% by volume were obtained.
Furthermore, 183 kg/hr of the reaction product overflowed from the reactor of the second step. Other results were as shown in Table 1.
COMPARATIVE EXAMPLE 1
This experiment was carried out in the same manner as in Example 1 except that potassium chloride and conc sulphuric acid were fed directly to the reactor of the second step, and the retention time inside the reactor was 2 hours. 71.7 Nm3/hr of hydrogen chloride having a concentration of 60% by volume and 1 84 Kg/hr of a reaction product were obtained. The other results were as shown in Table 1.
TABLE 1
Results of reaction
Reaction product of first step Reaction product of second step Cl conversion Cl conversion 01% HiSO4 % % Cl % H2SO4 % Example 1 18.6 4.3 42.9 2.7 1.07 93.4 Comparative Example 1 3.5 2.13 91.4 It is evident from Table 1 that in the case of Comparative Example 1, the amount of chlorine and that of sulphuric acid are both larger and the reaction has not gone sufficiently far.
Claims (5)
1. A process for producing potassium sulphate by reacting potassium chloride was sulphuric acid, which comprises:
(1) reacting potassium chloride and sulphuric acid in a molar ratio of 2.0 to 2.2 mols of potassium chloride to one mol of sulphuric acid with mixing at a temperature of from room temperature to 10000 to form potassium hydrogen sulphate; and then
(2) reacting the potassium hydrogen sulphate with unreacted potassium chloride at a temperature of 3000 to 4000C to produce potassium sulphate.
2. A process according to claim 1, wherein step (1), the formation of potassium hydrogen sulphate, is continuously carried out in a first step reaction zone, and step (2), the formation of potassium sulphate, is continuously carried out in a second step reaction zone separated from said first step zone.
3. A process according to claim 2, wherein reactants contained in said second step reaction zone are indirectly heated only from above.
4. A process according to Claim 2 or 3, wherein the reaction product of the second step is recovered by overflow.
5. A process according to any preceding claim, wherein the product potassium sulphate contains a small amount of unreacted potassium chloride.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9181179A JPS5617921A (en) | 1979-07-19 | 1979-07-19 | Manufacture of potassium sulfate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2053881A true GB2053881A (en) | 1981-02-11 |
| GB2053881B GB2053881B (en) | 1983-09-14 |
Family
ID=14037005
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8023793A Expired GB2053881B (en) | 1979-07-19 | 1980-07-21 | Process for producing potassium sulphate |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS5617921A (en) |
| CA (1) | CA1169630A (en) |
| ES (1) | ES8105962A1 (en) |
| GB (1) | GB2053881B (en) |
| IT (1) | IT1149206B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2523567A1 (en) * | 1982-03-19 | 1983-09-23 | Onoda Chem Ind Co Ltd | PROCESS FOR PRODUCING POTASSIUM SULFATE |
| US4420468A (en) * | 1981-06-15 | 1983-12-13 | Chisso Corporation | Method of treating converted potassium sulfate for reducing a small amount of chlorine contained therein |
| EP3647300A1 (en) | 2018-11-01 | 2020-05-06 | Tessenderlo Group NV | Potassium sulfate containing trace elements |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1177222A (en) | 1980-09-30 | 1984-11-06 | Hidemaro Iwashita | Apparatus for producing an alkali metal salt of a mineral acid, and a process |
| CN1042722C (en) * | 1995-07-23 | 1999-03-31 | 云南磷肥厂 | Non-recovery process for producing potassium sulphate by Mannheim furnace |
-
1979
- 1979-07-19 JP JP9181179A patent/JPS5617921A/en active Granted
-
1980
- 1980-06-27 CA CA000355026A patent/CA1169630A/en not_active Expired
- 1980-07-10 IT IT49212/80A patent/IT1149206B/en active
- 1980-07-18 ES ES493528A patent/ES8105962A1/en not_active Expired
- 1980-07-21 GB GB8023793A patent/GB2053881B/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4420468A (en) * | 1981-06-15 | 1983-12-13 | Chisso Corporation | Method of treating converted potassium sulfate for reducing a small amount of chlorine contained therein |
| FR2523567A1 (en) * | 1982-03-19 | 1983-09-23 | Onoda Chem Ind Co Ltd | PROCESS FOR PRODUCING POTASSIUM SULFATE |
| EP3647300A1 (en) | 2018-11-01 | 2020-05-06 | Tessenderlo Group NV | Potassium sulfate containing trace elements |
Also Published As
| Publication number | Publication date |
|---|---|
| IT8049212A0 (en) | 1980-07-10 |
| ES493528A0 (en) | 1981-07-01 |
| IT1149206B (en) | 1986-12-03 |
| GB2053881B (en) | 1983-09-14 |
| ES8105962A1 (en) | 1981-07-01 |
| JPS6256085B2 (en) | 1987-11-24 |
| JPS5617921A (en) | 1981-02-20 |
| CA1169630A (en) | 1984-06-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19950721 |