EA002709B1 - Method of formulating alkali metal salts - Google Patents

Abstract

1. A method of formulating food grade sodium bicarbonate and potassium sulfate, comprising the steps of: a) providing a source of liquid sodium sulfate; b) providing a source of ammonium bicarbonate to precipitate sodium bicarbonate; c) contacting said sodium sulfate and said ammonium bicarbonate; d) precipitating sodium bicarbonate and forming a liquor; e) filtering said sodium bicarbonate; f) saturating liquor from step e) with sodium sulfate; g) contacting said liquor with ammonium carbonate ammonia gas or carbon dioxide to precipitate further sodium bicarbonate; h) filtering precipitated sodium bicarbonate from step g); i) combining sodium bicarbonate precipitate from step e) and h) and washing to form food grade sodium bicarbonate; j) cooling liquor from step i) to 0 degree C to at least form Glauber's salt precipitate; k) treating liquor from step j) with sulfuric acid to convert carbonate minerals to sulfate minerals and release carbon dioxide gas; l) heating liquor from step k) to between 30 degree C and 40 degree C; and m) precipitating potassium sulfate by contacting said liquor from step l) with potassium chloride. 2. The method as set forth in claim 1, further including the step of separating precipitated potassium sulfate and washing with potassium chloride. 3. The method as setforth in claim 2, further including the step of treating liquor from said step of separating precipitated potassium sulfate with lime to liberate ammonia gas. 4. The method as set forth in claim 3, further including the step of recycling said ammonia gas to step g). 5. The method as set forth in claim 4, characterized in that the method further includes the step of evaporating filtrate from claim 4. 6. The method as set forth in claim 1, characterized in that said sodium sulfate has a specific gravity of between 1.30 and 1.34 at 40 degree C. 7. The method as set forth in claim 1, characterized in that said liquor from step d) has a specific gravity of 1.25 and contains, by weight, 10.4% sodium sulfate, 17.1% ammonium sulfate, between 8% to 12% sodium bicarbonate and an excess of ammonium bicarbonate. 8. The method as set forth in claim 1, characterized in that said sodium sulfate from step e) comprises Na2SO4 x10 H2O. 9. The method as set forth in claim 1, characterized in that said liquor from step f) has a specific gravity of 1.285 at 40 degree C. 10. The method as set forth in claim 1, characterized in that said liquor from step k) is a saturated liquor of sodium sulfate, ammonium sulfate and sodium bicarbonate. 11. The method as set forth in claim 1, characterized in that said potassium sulfate is generated in a yield of at least 80% with a purity of at least 98%. 12. The method as set forth in claim 1, characterized in that said potassium sulfate is generated in a yield of at least 80% with a purity of at least 98%. 13. A method of formulating food grade sodium bicarbonate and potassium sulfate, characterized in that the method comprises the steps of: a) providing a source of liquid sodium sulfate; b) providing a source of ammonium bicarbonate; c) contacting said sodium sulfate and said ammonium bicarbonate; d) precipitating sodium bicarbonate and forming a liquor; e) precipitating sodium bicarbonate and forming a liquor by contacting said liquor from step d) with sodium sulfate; f) saturating said liquor from step d) with sodium sulfate; g) filtering solids from said liquor of step e); h) contacting said liquor from step f) with sulfonic acid to precipitate carbonates; i) cooling said liquor from step h) to 0 degree C to form Glauber's salt precipitate; j) heating said liquor from step I) to between 30 degree C to 40 degree C; and k) treating said liquor from step j) with potassium chloride to precipitate potassium sulfate; l) evaporating liquor from step k) to recover potassium values for recycling to step k); and m) drying said potassium sulfate. 14. The method as defined in claim 13, further including the step of treating liquor remaining from step I) with lime and ammonium chloride. 15. The method as defined in claim 14, wherein ammonia gas is liberated and recycled. 16. The method as defined in claim 13, wherein used potassium chloride solution is recycled to step k).

Description

The present invention relates to a method for preparing alkali metal salts and, in particular, to a method for preparing edible sodium bicarbonate and potassium sulfate for use as a mineral fertilizer.

Background of the invention

There are many ways to obtain alkali metal salts. For example, there are many ways to obtain sodium bicarbonate. However, the work of previous installations for the synthesis of bicarbonate was complicated by unproductive energy consumption, which led to an increase in the cost of synthesis. Another limitation is the low productivity of salt production plants. Typically, obtaining a high-quality product is accompanied by the formation of poor quality by-products that cannot be used for commercial purposes, or for which commercial use requires too high costs.

An example of a prototype is the method described in US Pat. No. 3,429,657 issued February 25, 1969 to O'Lgs. This patent describes a method for extracting and obtaining potassium salts. Potassium-containing brine reacts with sodium perchlorate with precipitation of potassium perchlorate. Potassium is removed by ion exchange with sodium, and then free potassium enters into a chemical bond with chlorine, sulfate, nitrate.

Industrial application

The present invention can be used in the production of mineral fertilizers.

Description of the invention

One of the purposes of the present invention is to develop a method for preparing edible sodium bicarbonate and potassium sulfate, characterized in that its implementation includes the following several steps:

a) supplying liquid sodium sulphate;

b) supply of ammonium bicarbonate;

c) ensuring contact of sodium sulfate with ammonium bicarbonate;

b) precipitating sodium bicarbonate to form a solution;

e) precipitating sodium bicarbonate to obtain a solution by ensuring that the solution obtained in step b) is in contact with sodium sulfate;

I) saturation of the solution obtained in step e) with sodium sulfate;

e) filtering to separate the solid phase from the solution obtained in step 1);

Ii) ensuring the contact of the solution obtained in step d) with sulfuric acid to precipitate carbonates;

ί) cooling the solution obtained in step 1) to 0 ° C to obtain a Glauber's precipitate;

.)) heating the solution obtained in step ί) to a temperature of 30-40 ° C and

k) precipitating potassium sulphate by contacting the solution obtained in step.)) with potassium chloride.

Another objective of the present invention is to develop a method for the preparation of edible sodium bicarbonate and potassium sulfate, characterized in that its implementation includes the following several steps:

a) supplying liquid sodium sulphate;

b) supply of ammonium bicarbonate;

c) ensuring contact of sodium sulfate with ammonium bicarbonate;

b) precipitating sodium bicarbonate to form a solution;

e) precipitating sodium bicarbonate to form a solution by contacting the solution obtained in step b) with sodium sulfate;

l) saturating the solution obtained in step e) with anhydrous sodium sulfate;

e) filtering to separate the solid phase from the solution obtained in step 1);

1) ensuring contact of the solution obtained in step d) with at least one of the following reagents - ammonium bicarbonate, ammonia or carbon dioxide with the precipitation of sodium bicarbonate;

ί) cooling the solution obtained in step 1) to 0 ° C to obtain a precipitate of sodium bicarbonate and sodium sulfate and;

.)) precipitating potassium sulfate by contacting the solution obtained in step ί) with potassium chloride.

To remove sodium sulfate in the form of Glauber's salt and sodium bicarbonate after obtaining sodium bicarbonate, the solution is cooled to 0 ° C. The solubility of the G lauber's salt in this system is illustrated by the phase diagram of ammonium sulfate — sodium sulfate. With an increase in the concentration of sodium sulfate in the bicarbonate cycle with an increased level of reuse of the Glauber's salt, there is a tendency to a decrease in the solubility of bicarbonate and to an increase in the efficiency of the process.

As for the transition of the initial reagents to potassium sulfate, for this it is necessary to maintain the molar concentration of potassium and ammonium ions at a level of 5 or higher. This molar concentration provides a high conversion efficiency in the second stage of the process.

Brief description of the figures

FIG. 1 is a flow chart illustrating the first part of the process of the present invention;

in fig. 1a shows the second part of the process of FIG. one;

in fig. 1b is the third part of the process of FIG. one;

in fig. 2 is a flow chart illustrating the first part of an embodiment of the process of the present invention;

in fig. 2a — the second part of the process of FIG. 2; in fig. 2b is the third part of the process of FIG. 2. To the elements with the same name on figures are assigned the positions with the same name.

MODES FOR CARRYING OUT THE INVENTION

FIG. 1 to 1b shows the process of the present invention.

The source of liquid sodium sulphate 10 dissolved in fresh water and centrifuged water 12 is considered below. The solution is mixed in tank 14 at 40 ° C and its relative density is adjusted to a value of 1.30. The solution is filtered on the filter 16, the cell size of which may be, for example, 5 microns. The solid phases 18 are discarded while the filtrate 20 passes into the first crystallization vessel of sodium bicarbonate 27.

Water, ammonium and carbon dioxide (item 24) react in tank 24 to produce ammonium bicarbonate. The resulting ammonium bicarbonate is centrifuged in a centrifuge 26, the resulting solid phase is discharged into the crystallization tank 27. Recirculation loop 28 supplies the solid phase of ammonium bicarbonate and solution to the reactor 29. As a result, they are combined in sodium bicarbonate. The mixture is filtered on filter 30 and centrifuged. Sodium bicarbonate is washed with water in tank 32, centrifuged in centrifuge 34, and the resulting solid residue is edible sodium bicarbonate. The flushing water is returned to the tank 14.

The relative density of the solution at the exit of the filter 30 is 1.25, the solution includes about 10.4 (wt.%) Sodium sulfate, 17.1 (wt.%) Ammonium sulfate, 8 (wt.%) Sodium bicarbonate and excess amount of ammonium bicarbonate. to react with Glauber's salt (discussed below). The solution reacts in tank 36 at 40 ° C with the Glauber's salt obtained during the cooling of the technological process, which will be discussed below, to produce sodium bicarbonate from an excess amount of ammonium bicarbonate at the outlet of the crystallization tank 29. In another case, ammonium bicarbonate can be introduced in the second stage (capacity 36) in the form of a solid phase, suspension or solution.

To obtain a saturated solution of sodium sulfate / ammonium sulfate in the tank, the solution from tank 36 is added to sodium sulfate from source 41. To complete the reaction, ammonium bicarbonate can be used to obtain a solution of relative density 1.285. The suspension from tank 40 is filtered on filter 42. The solid phase of sodium bicarbonate 48 goes into tank 32, and solution 44 undergoes further processing by additional separation of sodium bicarbonate, which is returned to tank 32. After that, solution 44 is sent to tank 46 (Fig. 1a ). The volume of the circuit in the sodium bicarbonate cycle can be controlled by evaporation of purified sodium sulfate at the entrance to the system to obtain solid sodium sulfate, which ensures the saturation of the circuit.

The container 46 (Fig. 1a) contains sulfuric acid, which ensures the precipitation of carbonates. The composition thus treated is cooled to 0 ° C in the cooler 48 before the Glauber's salt is extracted and filtered on the filter 50. The extracted Glauber salt is returned to the crystallization tank of sodium bicarbonate 36.

The filtrate contains 25.25 (wt.%) Ammonium sulfate and up to 11 (wt.%) Sodium sulfate and enters the tank 52, is heated to a temperature of 30-40 ° C and combined with the solid phase 65 from filter 66. This solution enters capacity 54, where it reacts with solid potassium chloride to form a solution of ammonium chloride at a concentration of 20 (wt.%), the solution also contains approximately 20.2 (wt.%) ammonium chloride, 6.7 (wt.%) potassium chloride, 4.9 (wt.%) Sodium chloride, 2.3 (wt.%) (X) ₂ §0 ₄ , where x = Na, K and solid crystalline potassium sulfate, mixed with 10-20 (wt.%) Crystalline su ammonium loptate.

The solution is filtered on the filter 56 to form a solid fraction containing approximately 5 (wt.%) Potassium chloride, 80-85 (wt.%) Potassium sulfate, 10-15 (wt.%) Ammonium sulfate. This solid fraction is combined in a tank 58 with water and a saline solution of potassium chloride from the tank 60. The solid potassium sulfate is centrifuged and filtered on a filter 62 and recrystallized with a solution of potassium chloride at 25 ° C. The remaining ammonium sulfate goes into potassium sulfate. The output of potassium sulfate is more than 98 (wt.%).

Upon further processing, the solution or filtrate from the step of obtaining potassium sulfate, and in particular from the filter 56, is processed in accordance with the processing described in FIG. 1a The solution is evaporated in an evaporator to increase the concentration of ammonium chloride solution so that, after cooling, the solution of potassium chloride and sulphate residues occupy a minimum volume. The solution is filtered on the filter 66, and the solid fraction 67 is discharged into the tank 54 for reuse. The filtrate with a content of approximately 22-30 (wt.%) Ammonium chloride reacts with lime in the reactor 68, and the released ammonia is recycled. The resulting calcium chloride can be discharged to a sump 70 or scrubber 72, depending on the intended use in the future.

Below are examples of the method according to the present invention.

Example 1. Quenching bicarbonate before processing potassium sulfate.

At the entrance is fed 1 liter of solution with a relative density of 1.3, containing 360 g / l №2804

1st Stage. Getting JAN0 ₃ .

At the end of the reaction, salt solution is obtained.

130 g Ж8О4

213.8 g (ΝΗ4) 28θ4

100 g №NSO3

10.4 (wt.%) \ A _; 8A _:

17.1 (wt.%) (ΝΗ4) 28θ4

8.0 (wt.%) X'AHCO.

40 ° C

0.95 liters of solution relative density 1,250

1350.8 g

It turns out 172 g of solid Janso ₃ Consumed 55 g ΝΗ ₃

142.5 g CO ₂

2nd Stage.

A) 25.07 g IN ₃ + 64.9 g CO ₂

B) 51.2 g XII; + 132.6 g CO ₂

907 g H20

0.95 l of brine from the 2nd stage dissolves

A) 1 mole C) 2 mol No. 80a'10N ₂ O No. 2804-10H20 (332 g) (664 g) 272 g №2804 16.2 (wt.%) 414 g №2804 20.7 (wt.%) Ea ₂ 80 ₄ 213.8 g Να ₂ 80 ₄ 213.9 g 10.7 (wt.%) (ΝΗ4) 2804 12.8 (wt.%) (ΝΗ4) 2804 (ΝΗ4) 2804 100 g JAN0 ₃ (ΝΗ4) 2804 100 g JAN0 ₃ 5.0 (wt.%) JAN0 ₃ 1087 g H ₂ 0 5.9 (wt.%) 1267 g H ₂ 0 63.4 (wt.%) H ₂ O 1672.8 g JAN0 ₃ 1999 1,313 l 65.1 (wt.%) Н20 1.5 l brine at relative density brine at relative density 1.275 1,300

The composition of the solution obtained in the 2nd stage

A) 167.3 g 10 (wt.%) Να ₂ 80 ₄ \ a _; 8SG 18.9 (wt.%) 311 g (ΝΗ4) 2804 (ΝΗ4) 2804 8 (wt.%) JANCO ₃ 131 g HANSO; 63.1 (wt.%) H ₂ O 1087 g H ₂ O 1644.5 g A) 200 g Ia ₂ 80 ₄ 10 (wt.%) Ia ₂ 80 ₄ 412 g 20.2 (wt.%) (4) 2804 (ΝΗ4) 2804 160 g Jonas ₃ 8 (wt.%) JonS0 ₃ 1267 g H ₂ 0 61.8 (wt.%) H ₂ 0 2039 g Obtaining 92.9 g JANSO ₃ 1.31 l of brine with a relative density of 1.265 Obtaining 193.2 g JANo _{3 3} 1.6 l of brine with a relative density of 1.285

Bicarbonate quenching

412 g №2804

200 g ( ₄ ) ₂ 80 ₄ 160/84 (2) х 98 = 93.3 g

H2804 +

160 g JAN0 ₃

1267 g N ₂ O

2039 g (1.6 l) of brine with a relative density of 1.285

We get:

412 g (ΝΗ4) 2804

335 g Ia ₂ 80 ₄

1267 g N ₂ O

2014 g of brine with a relative density of 1.265 = (1.6 l)

For relative density

1.30 you need to add Ia ₂ 80 ₄ .

1.6 liters x 1.30 = 2080

In this way:

412 g ( ₄ ) ₂ 80 ₄

400 g Nos80 ₄

1267 g H ₂ 0

Total: 2079 g (1.6 l) of brine

Cooling:

412 g (ΝΗ4) 2804

116 g №2804

907 g H2O

28.7 (wt.%)

8.0 (wt.%) (Wt.%)

1435 g of brine

Submission to the evaporator inlet:

ID ₄ C1 330,8 g 21.9 (wt.%) KC1 130 g 8.6 (wt.%) IAS1 94.7 g 6.3 (wt.%) x-80 ₄ 50 g 3.3 (wt.%) Η20 907 g 1512 g 60.0 (wt.%)

If 33 (wt.%) IN ₄ C1, then - 2.8 (wt.%) KC1, then - 2.0 (wt.%) K ₂ 80 ₄

We get: 330.8 / 0.33 = 1002 g

Evaporation 907 - 623 = 284 g 0.79 t / t No. 80 ₄ add 0.5 tons per wash 1.29 tons N ₂ O / t

Να ₂ 80 ₄

Reaction K2804

a) Κ ₂ δΟ ₄ of (ΝΗ ₄ ) ₂ δΟ ₄ = 412/132 χ 174 = 543 g

b) Κ ₂ δΟ ₄ of No. ₂ 8Ο ₄ = 116/142 χ 174 = 142 g

c) Losses Κ ₂ δΟ ₄ = -43 g

Total: Κ ₂ δΟ ₄ 642 g

Removing the KC1

a) KC1 intermediate reaction = 685/174 χ 2 χ 74 = 582 g

The basic calculation for loading 1 t Ν; · ι ₂ δΟ. · Ι

b) 1 <C1 (loss with tails) = 50 g

c) Thus, the required amount of 1 <C1 = 632 g yield Κ ₂ δΟ ₄ = 642/685 χ 100 = 93.7 (wt.%) The conversion efficiency 1 <C1 is 582/632 χ 100 = 92.1 (wt. %)

The amount of feed The resulting product The first stage 0,153 t IN ₃ 0,396 t CO ₃ 2.52 t N ₂ O 0.48 t JANOSOZ The second stage 644 g ^^ LON ^ 0,142 t ΝΗ ₃ 0,368 t СО ₂ 0.53 t JANSO ₃ Bicarbonate quenching + saturation Να ₂ δΟ. _four Filter to obtain a clear solution 0.26 t Η ₂ δΟ ₄ 0.18 t Ν α ₂ δΟ. ₄ Cooling to 0 ° C BTU 1.8 t Να ₂ δΟ ₄ · 10Η ₂ Ο Brine cooling 1.14 t (ΝΗ ₄ ) ₂ δΟ ₄ 28.7 (wt.%) 0.32 t Ν α ₂ δΟ ₄ 8.0 (wt.%) 63 (wt.%) 2.52 t Η ₂ Ο Total: 3.99 t KS1 = 1.76 t 1.78 t Κ ₂ δΟ ₄ Evaporation to 33 (wt.%) AI ₄ C1 0.92 t AI ₄ C1 Solid phases: 1.29 t / t HaAST 0.08 t KS1 0,28 t KS1 0.05 t Κ ₂ δΟ ₄ 0.08 t Κ ₂ δΟ ₄ 1.73 t Η ₂ Ο 0.36 tons for reuse Total: 2.78 tons vocation Liming with 85% tap 0.955 t of CaCl ₂ (0.57 t) CaO 0,29 t ΝΗ ₃ 0.08 t KS1 Brine: 0.05 t Κ ₂ δΟ ₄ 1.73 t NG) 2.815 t at a temperature of from 75 to 90 ° C

FIG. 2 to 2b show another flow chart. In this scheme, before obtaining sodium bicarbonate, the solutions are saturated with anhydrous substances.

In this embodiment, sodium bicarbonate is produced in the crystallizer 22 and it passes through essentially the same steps as in FIG. from 1 to 1b. The brine or filtrate is saturated with anhydrous sodium sulfate in the tank 36 and filtered on the filter 38 to remove insoluble substances that are discarded. The filtrate obtained at this stage reacts with ammonium bicarbonate in tank 80. In another embodiment, the filtrate can react with ammonia or carbon dioxide to precipitate sodium bicarbonate. The solution is filtered, and sodium bicarbonate is retained on filter 82. This sodium bicarbonate is then combined with sodium bicarbonate at the output of filter 30 and then washed, centrifuged and dried. These steps are not shown.

The content of the remaining filtrate is 10 (wt.%) Sodium sulfate, 24 (wt.%) Ammonium sulfate and 8 (wt.%) Sodium bicarbonate. The relative density of the solution is 1.285 at 40 ° C.

From this stage, the filtrate solution enters cooler 84, where it is cooled to approximately 0 ° C to obtain a filtrate, which consists of approximately 5 (wt.%) Sodium sulfate, 28 (wt.%) Ammonium sulfate and 6 (wt.%) sodium bicarbonate. This solution is filtered on filter 86 and the precipitated sodium bicarbonate and sodium sulfate are fed back for reuse to the inlet of the crystallization tank of bicarbonate, and the filtrate at this time reacts with potassium chloride in tank 88 to produce potassium sulfate of the first stage with a purity of 75-90 (wt. .%) Solid potassium sulfate from the tank 92 is re-mixed with the potassium chloride solution in the tank 94 to form a suspension. The resulting product is washed with water at the stage of washing 96 and enters for reuse in the tank 94.

The solution from the filter 90 is evaporated in an evaporator apparatus 98 (FIG. 2a) to concentrate the ammonium chloride solution with a decrease in the volume of potassium chloride and sulphates after cooling. The solution is filtered on the filter 100, and the precipitate of potassium chloride and (x) 80 ₄ (where x = K, Να) are recycled to tank 88.

The filtrate from the output of the filter 100 containing ammonium chloride, potassium chloride and potassium sulfate is fed to the inlet of the evaporator 102. Sodium bicarbonate reacts, resulting in the release of ammonia and carbon dioxide. Then these gases enter the scrubber and are processed using appropriate technologies. Then, the resulting calcium chloride is discarded as waste or sold.

Example 2. Refusal to quench bicarbonate.

At the entrance is fed 1 liter of solution with a relative density of 1.3, containing 360 g / l No. 80 ₄ .

1st Stage

Getting Janso ₃

At the end of the reaction, a salt solution is obtained:

130 g №2804 10.4 (wt.%) Ea ₂ 80 ₄ 40 ° C 213.8 g (ΝΗ4) 2804 17.1 (wt.%) (ΝΗ4) 2804 0.95 l of solution 100 g JAN0 ₃ 8.0 (wt.%) Chanco ₃ relative density 1,250 907 g N ₂ O 1350.8 g

Turns out

Consumed

172 g of solid HHCO ₃ g HH ₃

142.5 g CO ₂

Re-saturation of No. 8 ₄ : the content of No. 8 ₄ in brine is maintained at 150 g. Then this brine is filtered and fed to the input of the HANCO ₃ crystallizer _{of the} second stage.

Starting material Reaction Outlet brine The resulting product 35.9 g UN ₃ 130 g №2804 177 g Janos ₃ 280 g Ia ₂ 80 ₄ 92.9 g CO2 353 g (ΝΗ4) 2804 213.8 g (ΝΗ4) 2804 100 g JAN0 ₃ 100 g Janos ₃ 907 g H20 907 g H ₂ 0 1490 1490.8 g 1.15 L of brine with 1.15 L of brine relative density with relative density 1.285 23.7 (wt.%) ( ₄ ) ₂ 80 ₄ nosti 1.32

After that, the resulting brine is cooled to 0 ° C.

The composition of the brine: 5,0% Να ₂ 80 ₄ . This means that 60 g Ia ₂ 80 ₄ is precipitated in the form of 130 g Ν; · ι ₂ 8 0 ₄ · 10Н ₂ О and 76 g Н ₂ 0 is discharged.

Thus 907 - 76 = 831 g H ₂ 0.

The composition of the brine at 0 ° C and relative density of 1.26.

g ia ₂ 80 ₄

353 g ( ₄ ) ₂ 80 ₄

100 g Janos ₃

831 g Η ₂ 0

Total: 1354 g

About 1 L of brine

K2804

a) 70 g of Ia ₂ 80 _4/142 x 174 = 85.8

b) 353 g (ΝΗ _{4) 2} 80 _4/132 x 174 = 465.3 g

Saline solution at the exit: 283 g Ν RS1 21.9 (wt.%) 57 g \ AC1 4.8 (wt.%) 119 g (KANSO ₃ ) 9.2 (wt.%) 831 g H20 Total: 1290 g

Evaporation to 33.0 (wt.%) ID ₄ C1

The separation of NH ₃ and CO ₂ from the evaporator, but at the same time the salt ΝΗ ₄ 1 is formed from KC1, and not from Iac1. KC1 is extracted in the same way as in example 1.

Basic calculation for loading 1 t Ia ₂ 80 ₄

The amount of feed The resulting product The first stage 0.15 t NN ₃ 0.396 t СО3 2.52 t H20 The second stage 0.10 t NN3 0.48 t \ a || (. '() _; 0.49 t HANSO,

maintained at a minimum level and the reaction proceeded at an acceptable rate.

The composition of the salt solution CaC

0.26 t СО2 0.42 t \; ι _; 8 <Т Cooling to 0 ° С Cooling brine КС1 = 1.62 t Evaporation to 33 ΝΙ1 ₄ C1 (wt.%) 0.7 t Н2О Contour control 0.5 t = 1.2 t Н2О per 1 Flushing = t № ₂ 8О ₄ To the evaporator. Liming with a tap of 85% (0.61 t) CaO 0.4 t No. 28О _T 10Н2О 0.19 t No. 28O ₄ 5 (wt.%) 0.98 t 26 (wt.%) (LH ^ O., 7.4 (wt.%) 0.28 t HCO3 61.4 (wt.%) 2.31 t H2O Total: 3.76 t 1.8 t K28O ₄ Salt Solid solution phase: 0, 98 t MBS! 0.28 t KS1 0.08 t KS1 0.08 t K28O ₄ 0.15 t \ aC1 out of 0.36 tCO3 1.57 t H2O Total: 2.97 t 1.01 t CaC12 0.08 t KS1 0.34 t \ aC1 1.57 t H2O 3.0 t at a temperature of from 75 to 90 ° C

Example 3. Bicarbonate quenching - refusal to evaporate ammonium chloride.

The original solution of the number 1

412 g (ΝΗ4) ₂ 8Θ4

335 g No8O ₄

1267 g N ₂ O

2014 g with a relative density of 1.265 = 1.60 l

Cooling to 0 ° C results in a filtered solution:

28.7 (wt.%) 8.0 (wt.%) (Wt.%)

412 g (ΝΗ4) 2§04

116 g Να ₂ 80 ₄

907 g N ₂ O

1435 g of solution

Then this brine is heated to 25 ° C and KC1 is added to it to obtain K ₂ 8O ₄ . The salt solution at the outlet of the K ₂ 8O ₄ circuit has the following composition:

ΝΗ.φ'Ί 330,8 g 21.9 (wt.%) KC1 130 g 8.6 (wt.%) ΝηΟ 94.7 g 6.3 (wt.%) X-8O4 50 g 3.3 (wt.%) 1RO 907 g 60 (wt.%) Total: 1512 g

x = Να / Κ

Then this brine is heated and reacts with lime to extract ammonia and bypasses the evaporator. KC1 is returned to the CaCl ₂ brine, and not removed in an evaporator. This represents from 15 to 20% loss of K in the salt solution of CaC12. SaS12 KC1 concentration in the solution can be lowered to 1.0 (wt.%) By introducing the solid №8O ₄ in hydrochloric SaS12 / KC1 solution. Potassium is effectively collected as co-precipitated syngenite (Ca8O ₄ · K ₂ 8O ₄ · xH ₂ O) at a temperature of from 0 to 100 ° C, although it is preferable that the temperature is from 20 to 30 ° C in order for the solubility of 8O ₄

343.3 g of CaCl ₂

130 g KS1

94.7 g №1S.'1 50 g h8O ₄

907 g N ₂ O 1525 g

22.5 (wt.%)

8.5 (wt.%)

6.3 (wt.%) (Wt.%) (Να / Κ)

59.5 (wt.%)

100 (wt.%)

Additive 140 g \ a _; 8 <T Salt solution at the output of 234.89 g of CaC12 15.25 g of KC1 209 g No. C1 50 g х8О ₄ 807 g 17.8 (wt.%) 1.1 (wt.%) 15.9 (wt.%) 3.8 (wt.%) + 61.3 (wt.%) Filtered sediment at the exit of 310 g of Ca8O ₄ · K28O ₄ 100 g of H2O

The salt solution at the outlet can be removed in a deep sump, and the filtered precipitate can be admixed with K ₂ 8O ₄ as a binder or subjected to further processing to remove Ca8O ₄ .

The filtered precipitate can react with (1MN ₄ ) ₂ HCO3 from the starting material of process No. 1NS.'O ₃ . CaCl ₃ quickly reacts to produce brine from (1MN ₄ ) ₂ 8O ₄ and K ₂ 8O ₄ , and the filter precipitates CaCl ₃ , which is discarded. The salt solution from (1MN ₄ ) ₂ 8O ₄ and K ₂ 8O ₄ enters for reuse in the crystallizer K ₂ 8O _{4 of the} first stage.

Explanation of the drawings

FIG. 1: 1 - solid phases; 2 - in capacity 32.

FIG. 16: 1 - for reuse; 2 - solid phases; 3 - air; 4 - vat residue to waste; 5 - in waste or for sale.

FIG. 2: 1 - solid phases; 2 - to the input of the cooler; 3 - solid NaΗCO ₃ .

FIG. 2a: 1 - from filter 82; 2 - to the dryer.

FIG. 26: 1 - for sale or in sump; 2 - for waste disposal.

Claims (16)

1. The method of preparation of food sodium bicarbonate and potassium sulfate, characterized in that its implementation includes the following steps: a) the supply of liquid sodium sulfate; b) supplying ammonium bicarbonate to precipitate sodium bicarbonate; c) contacting sodium sulfate with ammonium bicarbonate; b) precipitation of sodium bicarbonate to obtain a solution; e) filtering sodium bicarbonate; 1) saturation of the solution obtained in step e) with sodium sulfate; e) contacting said solution with ammonium carbonate, ammonia or carbon dioxide to precipitate sodium bicarbonate; j) filtering the precipitated sodium bicarbonate obtained in step e); ί) compounding the sodium bicarbonate precipitates obtained in steps e) and k) and washing them to obtain edible sodium bicarbonate; .)) cooling the solution obtained in step ί) to 0 ° C to obtain a precipitate G of the Lauber salt; k) treating the solution obtained in step.)) with sulfuric acid to convert carbonates to sulfates and release carbon dioxide; l) heating the solution obtained in step k) to a temperature of 30-40 ° C; and r) precipitation of potassium sulfate by providing contact of the solution obtained in step 1) with potassium chloride. 2. The method according to p. 1, characterized in that this method also includes the step of separating the precipitated potassium sulfate and washing with potassium chloride. 3. The method according to claim 2, characterized in that for the release of ammonia, this method also includes the step of processing the solution obtained in the step of separating the precipitated potassium sulfate with lime. 4. The method according to claim 3, characterized in that this method also includes the step of reusing said ammonia in step d). 5. The method according to claim 4, characterized in that this method also includes the step of evaporating the filtrate obtained according to claim 4. 6. The method according to p. 1, characterized in that the sodium sulfate has a relative density of from 1.30 to 1.34 at a temperature of 40 ° C. 7. The method according to p. 1, characterized in that the solution obtained in step 6) has a relative density of 1.25 and it includes 10.4 wt.% Sodium sulfate, 17.1 wt.% Ammonium sulfate, from 8 to 12 wt.% sodium bicarbonate and an excess of ammonium bicarbonate. 8. The method according to p. 1, characterized in that the sodium sulfate obtained in step e) contains Na ₂ §O ₄ -10H ₂ O. 9. The method according to p. 1, characterized in that said solution obtained in step ί) has a relative density of 1.285 at 40 ° C. 10. The method according to claim 1, characterized in that said solution obtained in step k) is a saturated solution of sodium sulfate, ammonium sulfate and sodium bicarbonate. 11. The method according to p. 1, characterized in that the yield of said potassium sulfate is at least 80%, and the purity is not less than 98 wt.%. 12. The method according to p. 1, characterized in that the yield of said potassium sulfate is at least 80%, and the purity is at least 98 wt.%. 13. The method of preparation of food sodium bicarbonate and potassium sulfate, characterized in that its implementation includes the following steps: a) supply of liquid sodium sulfate; b) supply of ammonium bicarbonate; c) contacting sodium sulfate with ammonium bicarbonate; 6) precipitation of sodium bicarbonate to obtain a solution; f) precipitation of sodium bicarbonate and obtaining a solution by ensuring contact of the specified solution obtained in step 6) with sodium sulfate; ί) saturation of the solution obtained in step 6) with sodium sulfate; d) filtering solid phases from the specified solution obtained in step e); j) contacting said solution obtained in step ί) with sulfuric acid to precipitate carbonates; ί) cooling said solution obtained in step k) to 0 ° C. to obtain a Glauber's salt precipitate; .)) heating the solution obtained in step ί) to a temperature of 30 - 40 ° C; k) treating said solution obtained in step _)) with potassium chloride to precipitate potassium sulfate; l) evaporating the solution obtained in step k) to replenish the potassium mass for reuse in step k); and r) drying said potassium sulfate. 14. The method according to item 13, wherein the method also includes the step of processing the solution remaining after stage 1), lime and ammonium chloride. 15. The method according to p, 14, characterized in that the ammonia is released and reused. 16. The method according to item 13, wherein the used potassium chloride solution is recycled in step k).