The method of producing potassium sulfate from potash and sodium sulfate

 

The present invention concerns a method of producing potassium sulfate from raw materials containing potash and sodium sulfate, which includes stages: (a) processing portion potassiumargon raw materials and containing sodium sulphate raw material, so that Glasurit crystallized out of solution and formed the first mother liquor; (b) conversion of glaserite in sedimentary sulphate of potash in the second the mother solution; (C) returning the second mother liquor in a portion potassiumargon raw materials and containing sodium sulfate raw materials; (d) the first crystallization mother liquor by evaporation to obtain sodium chloride in the third the mother solution, and (e) return the third mother liquor in a portion potassiumargon raw materials and containing sodium sulfate raw materials. The invention allows to reduce costs, to obtain potassium sulfate free of insoluble substances. 2 N. and 15 C.p. f-crystals, 7 ill., 1 PL.

The technical FIELD,

The present invention relates to methods for producing potassium sulfate, and more specifically, to methods for producing potassium sulfate from raw materials containing potash and sodium sulfate.

The LEVEL of TECHNOLOGY

The overall reaction obtain potassium sulfate from sodium sulfate and potash can opiat is deystviy thermodynamic interference system Na2SO4-2l-K2SO4-2NaCl/H2A. Data for this system is best represented in the phase diagram Janecke (Fig.1). The corresponding invariant points are:

(a) the equilibrium solution of Na2SO4, NaCl, K2SO4and glaserite (K3Na(SO4)2);

(b) the equilibrium solution of KCl, NaCl and glaserite;

(c) the equilibrium solution of KCl, K2SO4and glaserite.

The compositions of invariant points at 25Presented in the table.

From the phase diagram shows that for any initial mixture of potash, sulfate of sodium and water pure sodium chloride cannot be removed as a by-product. In addition, a significant conversion of potassium can only be achieved by using a two-step reaction via the intermediate product Glasurit consisting of (Fig.2A):

1) get glaserite of sodium sulfate of potash and solution stage 1;

2) obtain potassium sulfate and a solution of stage 2 of potash, water and glaserite stage 1.

Glasurit obtained in stage 1, is separated from the mother liquor and injected into stage 2. The mother liquor contains substantial amounts of dissolved potassium and sulphate, which usually provides the allocation process. Although known for the lia and sulfate, the reaction is very similar.

There are many problems associated with the separation of solid glaserite and fluid. As in the known methods Glasurit get through vysalivaniya, we obtain Glasurit is fine. Using vysalivaniya you can get and a few larger crystals, but this requires a longer residence time of material in the plant and more complex equipment for crystallization.

The fine particles of glaserite difficult to filter. In addition, the number of sticking the mother liquor increases sharply with decreasing particle size. This mother liquor rich in sodium (65-86 mol %) and chloride (75-95 mol %). A mixture of sodium and chloride, is introduced in stage 2, must be dissolved in the resulting solution. Because theoretical optimal operating point (invariant point KCl/K2SO4/Glasurit/N2O) the solution contains approximately 71% N2Oh and less than 3% of sodium, then in stage 2 is necessary to add about 25 kg of water, to completely remove the added sodium.

“Sodium poisoning”, resulting from the adhering mother liquor to Glasurit, increases the need for supplied energy also increases, because of the additional costs of heating and cooling for increased recirculation flows. Respectively increase and the cost of the equipment.

Large particles of glaserite easier filtered and contain much less mother liquor.

The use of Glauber's salt (decahydrate sodium sulfate) to obtain potassium sulfate is known in the art. It is well known that an additional amount of water from Glauber's salt reduces the conversion stages of the reaction and increases the content of sulfate in the flow resulting from stage 1. But some cyclic processes cannot be performed using Glauber's salt; others require additional operations (e.g., evaporation).

The ratio of water to sodium sulfate in solutions of sodium sulfate is significantly higher than in Glauber's salt, so the problem of excess water significantly exacerbated.

Thus, in accordance with the previously known method, water-containing raw material is sodium sulfate, typically crystallized by evaporation to obtain the anhydrous salt. Solids are separated from the mother liquor and injected into one of the usual technological schemes sulfate rastvorov sodium sulfate and the other containing sodium sulphate raw material is expensive as cash and energy. Thus, there is a recognized need in the method of producing potassium sulfate from these species containing sodium sulfate raw materials, more efficient and more economical than previously known methods.

The above methods are presented, for example, in U.S. patent 4215000 from 7/1980,, CL 423/552 author Sokolova or patent 5552126 from 9/1996,, CL 423/199 author Ephraim.

All these drawbacks are eliminated in this way obtain, described below.

Brief description of the invention

The first aim of the present invention is to obtain glaserite as an intermediate substance in obtaining potassium sulfate using evaporative crystallization, and not using vysalivaniya, resulting in a gain Glasurit having improved characteristics associated with sedimentation, filtration and ease of use, and with a lower content of the adhering mother liquor.

The second objective of the present invention is to provide a method of producing potassium sulfate from potash and sulphate of sodium, without obtaining anhydrous sodium sulphate or Glauber's salt, in an intermediate state.

The third objective of the present invention to provide a sulfate feces.

In the first embodiment, the present invention provides a method of producing potassium sulfate from potassiumargon raw materials and containing sodium sulphate raw material, comprising the stage of: (a) processing portion potassiumargon raw materials and containing sodium sulphate raw material, so that Glasurit crystallized from a solution that eliminates the need for intermediate - salts of sodium sulfate and formed the first mother liquor; (b) conversion of glaserite in sedimentary sulphate of potash in the second the mother solution; (C) returning the second mother liquor to the step (a); (d) the first crystallization mother liquor by evaporation to obtain sodium chloride in the third the mother solution, and (e) returning the third mother liquor to the step (a).

In one of the preferred embodiments of the invention at the stage of conversion glaserite in sedimentary sulfate potassium use additional portion potassamide raw materials.

In one of the preferred embodiments of the invention additional portion potassiumargon raw materials represents the excess part potassiumargon raw materials from stage (a).

In one of the preferred options to implement the crystallization by evaporation.

In one of the preferred embodiments of the invention processing stage portion potassiumargon raw materials and containing sodium sulphate raw material includes crystallization by cooling.

In one of the preferred embodiments of the invention portions potassiumargon raw materials and containing sodium sulfate raw materials are pre-mixed to obtain a solution before processing portion potassiumargon raw materials and containing sodium sulfate raw materials.

In one of the preferred embodiments of the invention containing sodium sulphate raw material includes Glauber's salt.

In one of the preferred embodiments of the invention containing sodium sulphate raw material includes a solution containing sodium sulfate.

In one of the preferred embodiments of the invention containing sodium sulphate raw material includes glauberyt.

In one of the preferred embodiments of the invention containing sodium sulphate raw material includes lumpy sodium sulphate (salt cake).

In one of the preferred embodiments of the invention containing sodium sulphate raw material includes sodium sulfate, the purity of which is from about 5% to about 90%.

is the temperature from about 15With up to about 110C.

In one of the preferred embodiments of the invention, the insoluble substances from potassiumargon raw materials and containing sodium sulphate raw material is removed by filtration, resulting in an essentially completely soluble sulphate of potash. The intermediate salt of sodium sulfate include Glauber's salt and/or anhydrous sodium sulfate.

Used in this description and the following claims, the term “solutions of sodium sulfate” refers to any solution containing dissolved sodium sulfate.

Used in this description and the following claims, the term “containing sodium sulphate raw material” refers to a solid substance and/or the solution containing sodium sulfate as a main component.

Used in this description and the following claims, the term “potassiumargon raw material” refers to a solid substance and/or the solution containing potassium chloride as a main component.

Used in this description and the following claims, the term “lumpy sodium sulphate” (salt cake) refers to the containing impurities sulfate of the invention, the term “essentially completely soluble” refers to the quality of potassium sulfate, suitable for fertigation and other applications requiring high purity of the substances.

It should be noted that in prior art the use of Glauber's salt, glauberite containing sodium sulfate aqueous solutions, etc., requires the inclusion of additional important stages of the process including melting, crystallization by evaporation (or both stages) and dehydration. These additional stages complicates the technological process and significantly increase the capital and operating costs.

In accordance with the prior art, the intermediate product Glasurit obtained by vysalivaniya, and he has poor performance associated with sedimentation, filtration and ease of use. Alternatively, you can use bulky and complex equipment for crystallization to improve the performance of particle size of glaserite.

Potassium sulfate obtained in accordance with the prior art contains insoluble substances from raw materials containing sodium sulfate and potash. Insoluble substances can hinder technological operations and, as a rule, make the final product - potassium sulphate - unsuitable for pertigalete the invention eliminates the need for additional process stages, associated with obtaining anhydrous sodium sulfate at an intermediate stage. In addition, since Glasurit obtained from the solution of the obtained crystals glaserite large, which greatly facilitates the operation associated with dehydration and application. In addition, the present invention allows to remove insoluble materials from the solution, causing the resulting potassium sulfate is essentially fully rastvorimym and is suitable for special applications, including fertigation.

Brief description of drawings

The present invention is described here with reference to the accompanying drawings, given only as an example, in which:

Fig.1a, 1b and 1C represent the phase diagrams of solutions for a system of Na2SO4/2NaCl/K2SO4/2KCl/H2O when 0With 25With 100With, respectively; and

Fig.2A and 2b represent a spatial diagram, schematically illustrating methods in accordance with the prior art;

Fig.3 shows the influence of humidity glaserite on the effectiveness of the method;

Fig.4 is a spatial diagram schematically depicting sposoby Na2SO4/2NaCl/K2SO4/2KCl/H2O.

The present invention describes methods for producing potassium sulfate from raw materials containing potash and sodium sulfate. The principles and the implementation of these methods in accordance with the present invention will be better understood from reference to the drawings and accompanying descriptions.

Fig.4 illustrates some embodiments of the present invention. Stage 1 is used to obtain glaserite 10. With this purpose, a mixed solution of 14 sodium sulfate, the first portion of the solid particles 18 potash and salt solution 23 from stage 2 (see below), so that the potash is dissolved. Dissolution 13 can be enhanced by heating. The resulting solution can be filtered to remove insoluble substances, and then subjected to crystallization, such as evaporative crystallization, crystallization by cooling, etc., resulting in Glasurit crystallizes from solution. Suspension is dewatered in the separator 19 and serves on stage 2, which is designed to decompose glaserite or get 20 potassium sulfate.

Stage 1 - getting glaserite 10 can be performed preferably at a temperature of from about 15 toWith up to about 110With up to about 50C.

The resulting stock solution has the following percentage composition (by weight): potassium 2,5-6%, sodium 7.5 to 10%, chloride 13-17%, sulfate 1,3-5% water remainder to 100%. The composition of the mother liquor corresponds to the points on the line of equilibrium NaCl/glaserite and above this line. The mother liquor has a high concentration of sodium and chloride, but also contains significant amounts of potassium and sulfate. The mother liquor is subjected to crystallization by evaporation in stage 3, 12. At this stage the resulting sodium chloride is separated from the mother liquor and was isolated as a side product 16. Potassium ions and sulfate focused in the mother solution, return to the step 1, 10.

In stage 2 the decomposition of glaserite 20 is carried out preferably at a temperature of from about 15 toWith up to about 90With, and the most preferred temperature range is from about 20With up to about 50S. Potash 18 and water 22 served with solids obtained PA stage 19 of the crystallization of glaserite. Potash 18 and water 22 can be mixed separately, and the resulting solution may be filtered to remove nerastvorim solid particles glaserite dissolve, resulting in oversaturation of only potassium sulfate, resulting potassium sulfate selectively precipitates. The maximum conversion gain in that case, if the mother solution approaches the invariant point KCl/K2SO4/Glasurit/N2O. Suspension 24 of potassium sulfate is separated 25, washed with water 22 and dried. The mother liquor is removed from the reactor, return to the previous stage; however, the wash water can be used in decomposing glaserite.

Although the invention is described using only a limited number of variants of its implementation, it should be borne in mind that there are numerous variations, modifications and other applications of this invention.

Claims

1. The method of producing potassium sulfate from potassiumargon raw materials and containing sodium sulphate raw material, comprising the stage of: (a) processing portion potassiumargon raw materials and containing sodium sulphate raw material so that Glasurit crystallized from the solution by evaporation or cooling with the ability to eliminate the need to obtain intermediate salts of sodium sulfate with the formation of the first matongo the mother liquor to the step (a); (d) crystallization of the specified first mother liquor by evaporation to obtain sodium chloride in the third the mother solution; (e) the return of the third mother liquor to the step (a).

2. The method according to p. 1, which in this stage of transformation glaserite in sedimentary sulfate potassium use additional portion potassiumargon raw materials.

3. The method according to p. 2, wherein the specified additional portion potassiumargon raw materials represents the excess of the given portion potassiumargon raw materials from stage (a).

4. The method according to p. 1, in which stage of processing portions potassiumargon raw materials and containing sodium sulphate raw material includes crystallization by evaporation.

5. The method according to p. 1, in which stage of processing portions potassiumargon raw materials and containing sodium sulphate raw material includes crystallization by cooling.

6. The method according to p. 1, in which potassiumargon raw materials and containing sodium sulfate raw materials are pre-mixed to obtain a solution before processing said portion potassiumargon raw materials and containing sodium sulfate raw materials.

7. The method according to p. 1, in which the specified containing sodium sulphate raw material includes Glauber's salt.

8. The method according to p. 1, in which the specified containing the containing a series of sodium sulphate raw material includes glauberyt.

10. The method according to p. 1, in which the specified containing sodium sulphate raw material includes lumpy sodium sulphate.

11. The method according to p. 1, in which the specified containing sodium sulphate raw material includes sodium sulfate having a purity of about 5 to 90%.

12. The method according to p. 1, in which the specified receiving glaserite is carried out at a temperature of about 15 - 110C.

13. The method according to p. 1, in which the insoluble substances from potassiumargon raw materials and containing sodium sulphate raw material is removed by filtration, obtaining essentially completely soluble sulphate of potash.

14. The method according to p. 1 which includes the intermediate salt of sodium sulfate include Glauber's salt.

15. The method according to p. 1 which includes the intermediate salt of sodium sulfate include anhydrous sodium sulfate.

16. The method according to p. 1 which includes the intermediate salt of sodium sulfate include Glauber's salt and anhydrous sodium sulfate.

17. The method of producing potassium sulfate from potassiumargon raw materials and containing sodium sulphate raw material consisting essentially of the steps (a) processing portion potassiumargon raw materials and containing sodium sulphate raw material so that Glasurit crystallized out of solution and formed the first matcheroo the mother liquor to the step (a); (d) crystallization of the specified first mother liquor by evaporation to obtain sodium chloride in the third the mother solution; (e) return the third mother liquor to the step (a).

 

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The invention relates to the field of chemical technology, namely a process for the production of potassium sulfate

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The invention relates to a continuous method of obtaining potassium sulfate

The invention relates to a method of producing potassium sulfate by reacting potassium chloride and sodium sulfate from the mother liquor of the sulfate of potassium with getting glaserite, Department of glaserite, interaction potassium chloride and water from getting sulfate and potassium stock solution of potassium sulfate, cooling the mother liquor of glaserite and crystallization of Glauber's salt, and the separation and recycling of Glauber's salt in stage crystallization glaserite

The invention relates to a technology for highly efficient chlorine-free potassium fertilizers - potassium sulfate conversion of sodium sulfate or mirabilite the potassium chloride in the aqueous medium education in the first stage of glaserite and genericowhere solution

FIELD: chemistry.

SUBSTANCE: method of processing waste potassium bifluoride comprises its grinding, treatment with sulfuric acid with concentration of 95-100% in a molar ratio of sulfuric acid: potassium bifluoride as 1:1.02. The resulting mixture is heated to 130-150°C and held for 3-4 hours. The resulting hydrogen fluoride is stripped. Hydrogen fluoride absorption by water to obtain hydrofluoric acid is possible. Neutralisation of mass remaining after stripping of the hydrogen fluoride is carried out using aqueous solution of hydroxide or potassium carbonate to pH 7-7.5.

EFFECT: resulting potassium sulfate is dried The invention enables to process waste potassium bifluoride having high acidity and toxicity into commodity products - hydrogen fluoride and/or hydrofluoric acid and clear potassium sulfate.

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