RU2548959C2 - Method of producing bisulphate and hydrogen chloride solution - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention can be used in chemical industry. The method of producing bisulphate and hydrogen chloride solution includes preparing a solution from a chloride, which contains one of bisulphate cations, and a hydrosulphate containing the second one of bisulphate cations, and precipitating bisulphate from the solution. Precipitation is carried out before removing the sulphate cation from the solution while simultaneously obtaining hydrogen chloride solution. The hydrosulphate containing the first of bisulphate cations used is sodium bisulphate, or potassium bisulphate, or ammonium bisulphate, or rubidium bisulphate or caesium bisulphate. The chloride which contains the second one of the bisulphate cations used is magnesium chloride, or aluminium chloride, or nickel chloride, or chromium chloride, or cobalt chloride, or manganese chloride, or copper chloride, or iron chloride, or cadmium chloride, or zinc chloride.

EFFECT: invention enables to simultaneously obtain bisulphates and a diluted solution of commercial-grade hydrochloric acid or an ore leaching solution or a solution for producing gaseous hydrogen chloride.

8 cl, 1 tbl, 5 ex

Description

The invention relates to chemical technologies and can be used to obtain simultaneously with double sulfate a solution of hydrogen chloride, suitable for use either as a dilute solution of hydrochloric acid or as a leaching solution or as a source for the production of gaseous hydrogen chloride to produce hydrochloric acid.

There are several dozen sulfates. Sources (Solubility Handbook, Vol. 1, Publishing House of the USSR Academy of Sciences, Moscow-Leningrad, 1961 [1], Chemical Encyclopedic Dictionary, edited by I. L. Knunyants, M. Sovetskaya Encyclopedia, 1983 [2]), solubility information in% at 0 ° C of some double sulfates. Many of these double sulfates are widely used in industry, they are produced in large quantities and, therefore, require the most economical production technology. So, for example, chromium-potassium double sulfate (chromium-hot alum) is used for tanning leather, in the production of film, in photography, as a pickle for dyeing, for soaking fabrics. Aluminum-potassium double sulfate (aluminum-alum) is used in cosmetology, in deodorants, in the pulp and paper industry, for wastewater treatment, as a baking powder in baking bakery products and as an acidity regulator and stabilizer. Nickel-ammonium double sulfate is used for chemical nickel plating. Iron-ammonium double sulfate (Mohr's salt) is used to impregnate wood to protect it from decay. Double cobalt-ammonium sulfate is used for cobalt, for staining glass and ceramics. Magnesium-ammonium double sulfate is used as a complex fertilizer.

A known method for the production of double sulfates (Klyuchnikov N.G.

Inorganic Synthesis Guide. - M .: Chemistry, 1965, S.332) [3] by the joint crystallization of two reagents, sulfates, forming double sulfate. The method is universal and allows you to get any double sulfate.

The disadvantage of this method is that double sulfate is produced only from sulfates containing cations that are part of the double sulfate. This severely limits the raw material base for the production of double sulfate, since in industry, as a rule, one of the cations can be widely represented as cheap chloride.

Known, for example, is a method of producing double nickel-ammonium sulfate (RU 2310610, publ. 20.11.2007) [4]. In the method, the source of one of the cations included in the double sulfate - nickel cation is not nickel sulfate, but nickel chloride contained in the spent chemical nickel plating solution. Precipitation is carried out by adding an excess of ammonium sulfate and sulfuric acid to the spent solution of chemical nickel plating, which serve as a source of the sulfate ion that binds nickel ion to double sulfate.

It should be noted that the addition of ammonium sulfate and sulfuric acid at the same time is equivalent to the introduction of a certain amount of an acid salt - ammonium hydrosulfate, which is instantly formed by the interaction of ammonium sulfate and sulfuric acid. As a matter of fact, even then, after its formation, ammonium hydrosulfate interacts with nickel chloride to form nickel-ammonium double sulfate by the crystallization reaction (the crystallization reaction itself has a slow rate compared to the instantaneous hydrosulfate formation rate, since supersaturation for double sulfate must be achieved first, then nucleation, and only then will crystal growth begin) and a solution of hydrogen chloride. But ammonium sulfate is introduced in excess, so the remaining ammonium sulfate interacts with the resulting solution of hydrogen chloride, again forming ammonium hydrosulfate. Since the nickel cation is no longer present, it is bound into nickel-ammonium double sulfate, this excess (relative to the precipitated nickel cation) of ammonium hydrosulfate remains in solution, i.e., after precipitation of the nickel-ammonium double sulfate, a solution of ammonium hydrosulfate remains. And hydrosulfate solutions have not found application in industry and should be disposed of.

Thus, the disadvantage of the method [4] is the formation in the production of double nickel-ammonium sulfate solutions of acidic sulfates, which cannot be used in industry and which must be disposed of. The same is true with respect to the methods (RU 2337878, publ. 10.11.2008 [5], RU 2314260, publ. 08.20.2007 [6], RU 2307793, publ. 10.10.2007 [7]).

The objective of the present invention is the simultaneous production of not only double sulfate using one of the cations as the source of chloride of this cation, but also a solution of hydrogen chloride, which can be used in industry.

To solve this problem, the method includes the manufacture of a solution from chloride containing one of the double sulfate cations and hydrogen sulfate containing the second of double sulfate cations, precipitation from the double sulfate solution, while the deposition is carried out until the sulfate ion is removed from the solution while obtaining a solution of hydrogen chloride .

As the chloride containing the second of the double sulfate cations, either magnesium chloride or aluminum chloride or heavy metal chloride is used, preferably: either nickel chloride or chromium chloride or cobalt chloride, or manganese chloride or copper chloride or iron chloride or cadmium chloride or zinc chloride

If a non-monovalent cation hydrosulfate, for example magnesium hydrosulfate, is used as the hydrosulfate containing the first of the double sulfate cations, then the monovalent chloride is preferably used as the chloride containing the second of the double sulfate cations.

As the hydrosulfate containing the first of the double sulfate cations, a monovalent cation hydrosulfate, i.e. either sodium hydrosulfate or potassium hydrosulfate or ammonium hydrosulfate or rubidium hydrosulfate or cesium hydrosulfate, is preferably used.

Precipitation of the double sulfate having low solubility before removing the sulfate ion from the solution is preferably carried out by cooling to the minimum solubility of the double sulfate. Precipitation of double sulfate having medium or high solubility, before removing sulfate ion from the solution, is preferably carried out simultaneously by cooling, and salted out with an excess of chloride containing one of the cations that make up the double sulfate, but not the sulfate of this cation.

According to the claimed method, after the precipitation of double sulfate, before removal of the sulfate ion from the solution, a solution of hydrogen chloride is obtained. For double sulphate having low solubility, the hydrogen chloride solution preferably has the quality of diluted technical hydrochloric acid in the concentration of impurities in the solution. For double sulphate having moderate solubility, the hydrogen chloride solution preferably has a quality of hydrogen chloride solution sufficient to leach ore concentrates, preferably having a chemical element similar to the cation of the chloride, which salutes the double sulfate, and to produce gaseous hydrogen chloride. For double sulphate having high solubility, the hydrogen chloride solution has preferably a quality of hydrogen chloride solution sufficient to produce gaseous hydrogen chloride.

The essence of the claimed method is as follows. A chloride solution is prepared containing one of the double sulfate cations and a hydrosulfate containing the second of the double sulfate cations. A crystallization reaction is carried out, before the sulfate ion is removed from the solution, and after the crystallization reaction between these substances is complete and the formation of double sulfate crystalline hydrate, a hydrogen chloride solution is obtained. The result is a pulp consisting of a solution of hydrogen chloride and sparingly soluble precipitate from double sulfate, which is separated.

Before the formation of double sulfate crystalline hydrate, ions in the solution were formed during the dissolution of hydrosulfate containing the second of the double sulfate cations: Me 2й ⁺ , HSO ₄ ^- , H ⁺ and SO ₄ and ions formed during the dissolution of chloride containing the first of the double sulfate cations, Me ^{1st +} , Cl ^- , while the hydrosulfate dissociation proceeded along the first stage on Me 2y ⁺ and HSO ₄ ^- and to the second degree on H ⁺ and SO ₄ ^- , the number of H ⁺ ions was small and was determined by the dissociation constant (HSO ₄ ^- ) K _a = 1,2 _* 10 ^-2, pH of the solution was equal to approximately 0.5 and corresponded force cf. acid days, which is typical behavior of acidic sulfate salts. After removal of Me ^{2 + +} and SO ₄ ^- ions from the solution by binding of ions to double sulfate in the solution, additional dissociation of HSO ₄ ^- into SO ₄ ^- and H ⁺ begins, and the number of H ⁺ ions increases, the pH of the solution becomes approximately -0.5 -0.1, which corresponds to a solution of a strong acid. Since, according to the method, double sulfate is precipitated from the solution until sulfate ions SO ₄ ^{- are} removed from the solution, this is already a solution of hydrogen chloride, a strong acid.

The formation of double sulfate requires the presence of two cations forming a double sulfate with a sulfate ion. If the first cation, for example, a monovalent ammonium cation, comes with ammonium hydrogen sulfate, then the second cation, for example, magnesium cation, must come with magnesium chloride to form double magnesium-ammonium sulfate and a solution of hydrogen chloride. And vice versa, if the first cation, for example, a monovalent ammonium cation, comes with ammonium chloride, then the second cation, for example, a magnesium cation, must come with magnesium hydrosulfate, to form the same double magnesium-ammonium sulfate and a solution of hydrogen chloride. Precipitation of low solubility double sulfate by cooling to its minimum solubility is preferable, because the lower its solubility, the less will remain in a solution of a sulfate ion forming a hydrosulfate containing the second of the double sulfate cations, and accordingly the less will remain in a solution of chloride containing the first of the double sulfate cations, the more pure and concentrated a solution of hydrogen chloride will be obtained, which important for using dilute hydrochloric acid solution. The minimum solubility of double sulfates is taken as their minimum solubility in weight percent in water without ice formation in water. The solubility of double sulfates is considered to be low if it is equal to or lower than the solubility of KAl (SO ₄ ) ₂ ↓ * 12 H ₂ O. Precipitation of a double sulfate of medium and high solubility is preferably simultaneous cooling to the minimum solubility of a double sulfate and salted out with an excess of chloride containing one of the cations, included in the double sulfate present in leached ore, as the lower the solubility of double sulfate, the more concentrated a solution of hydrogen chloride will be obtained, which is important for its use as a solution for leaching. The solubility of double sulfates is considered average if it is higher than the solubility of KAl (SO ₄ ) ₂ ↓ * 12 H ₂ O, but lower than the solubility of (NH ₄ ) ₂ Fe (SO ₄ ) ₂ ↓ * 6 H ₂ O and high if this solubility is or higher than the solubility of (NH ₄ ) ₂ Fe (SO ₄ ) ₂ ↓ * 6 H ₂ O. When the quality of the hydrogen chloride solution is sufficient to leach ore concentrates, the presence of a cation in the leach solution, including in the ore, will not negative impact on leaching results. If this solution is used for its desorption, then in order to accelerate the process, chlorides must be added to it; therefore, the chlorides added to the solution during the deposition of double sulfate will not adversely affect the desorption.

Thus, the claimed method for the production of double sulfate,

includes the production of a solution of hydrogen chloride, the use of which will be carried out in a known manner either as a dilute solution of industrial hydrochloric acid or as a solution for leaching ore or as a raw material for producing gaseous hydrogen chloride.

A new technical result achieved by the claimed method is to expand the production capabilities of double sulfates by simultaneously producing double sulfate, as well as a dilute solution of technical hydrochloric acid or a solution for leaching ore or raw materials to produce gaseous hydrogen chloride.

According to the theory of experimental design for experimental verification of the method, there is no need to conduct several hundred experiments with obtaining all possible double sulfates and at the same time receive and check the quality of a solution of hydrogen chloride. It is enough to conduct experiments with obtaining each variety of double sulfates according to certain criteria. The following criteria were used: solubility - low, medium, high, high (even very high); use of a monovalent cation - specifically taken from all cations are ammonium, potassium, sodium; use of a divalent cation - specifically taken from all the cations are nickel, cobalt, magnesium; the use of a trivalent cation - specifically taken aluminum cation; the use in hydrosulphates of metals of different valencies — a monovalent cation — specifically cations of ammonium, potassium, sodium and a divalent cation — specifically taken are magnesium cation; obtaining different quality solutions of hydrogen chloride - a dilute solution of hydrochloric acid, a solution of hydrogen chloride suitable for leaching ore concentrates, a solution for producing gaseous hydrogen chloride.

For experimental verification of the proposed method, a table of information about the solubility in percent at 0 ° C of some double sulfates was compiled: (one cation from the vertical row, another cation from the horizontal row).

The verification was carried out according to the plan below:

For example 1: low solubility of bicarbonate, the working capacity of a pair: a monovalent cation with a divalent cation, the use of a monovalent cation of ammonium, the use of one of the divalent cations, the use of a monovalent cation in hydrosulfate, the preparation of a dilute hydrochloric acid solution.

For example 2: the low solubility of the double sulfate, the use of another monovalent cation - potassium cation, the pair is tested for performance: a monovalent cation with a trivalent cation. The trivalent aluminum cation is tested.

For example 3: the average solubility of double sulfate, the use of a monovalent ammonium cation, the use of another of the divalent cations

For example 4: the high solubility of the double sulfate, the use of the divalent cation in the form of hydrosulfate as the first of the cations, the use of the corresponding monovalent cation, the second of the cations in the form of chloride, the invariance of the production of double sulfate relative to the exchange of cations in hydrosulfate and chloride, salting out of the double sulfate by one of cations included in double sulfate, checking the possibility of using a solution of hydrogen chloride obtained by salting out to leach ore, checking POSSIBILITY producing gaseous hydrogen chloride from the solution obtained by salting out.

For example 5: the very high solubility of the double sulfate, the performance of the pair is checked: a monovalent cation with a monovalent cation, the use of a monovalent sodium cation.

Example 1

Double sulfate having low solubility is tested - nickel-ammonium sulfate, solubility at 0 ° C is 0.99%. The performance of the pair is checked: a monovalent cation with a divalent cation. Ammonium cation is tested. The monovalent cation in the hydrosulfate is tested. The divalent nickel cation is tested. Testing for dilute hydrochloric acid solution

As the chloride containing the first of the double sulfate cations, nickel chloride NiCl _{2 was used} ; as the hydrosulfate containing the second of the double sulfate cations, ammonium hydrosulfate NH ₄ HSO _{4 was used}

$$NiC{l}_2+2*N{H}_{\mathrm{four}}HS{O}_{\mathrm{four}}={\left(N{H}_{\mathrm{four}}\right)}_{2}Ni{\left(S{O}_{\mathrm{four}}\right)}_2\downarrow +2*HCl$$

Pour 100 grams of hot water into a heat-resistant glass and dissolve 22.99 grams of ChDA grade ammonium hydrosulfate in it, which is 0.200 moles of the reagent, the pH of the solution is 0.52, this corresponds to an acid salt solution. 50 grams of hot water were poured into a heat-resistant glass and dissolved in it 23.50 grams of nickel chloride 6 water grade H, this is 0.100 moles of reagent. The resulting solutions were mixed in a heat-resistant glass. The glass was placed in a cuvette filled with an alcoholic solution and pieces of ice, and they began to cool by stirring the solution and measuring the temperature and pH of the solution. As the solution cools, the pH of the solution decreases: at 11.4 ° C pH = 0.14, at 9.4 ° C pH = 0.10. At 8.8 ° C, pH = 0.07 and a noticeable cloudiness of the solution, at 4.6 ° C pH = -0.05, a precipitate has already formed, immediately settling to the bottom after stopping stirring, at 1.5 ° C pH = -0 , 14, at 0.6 ° C, pH = -0.15, further cooling loses its meaning. The rate of precipitation of the precipitate after mixing is very high, the solution becomes completely transparent in less than half a minute.

. Раствор с осадка слили, измерили pH декантата равный -0,15, что соответствует pH раствора уже не кислой соли, а раствора хлористого водорода. Объем декантата составил 128 мл, а вес 133 г. Осадок залили 20 мл холодной воды 6°C, перемешали, слили, процесс повторили, после чего осадок растворили в 150 г. горячей воды, измерили pH раствора равный 2,76 при температуре 43°C.Thus, a precipitate formed in the beaker as a result of the reaction of ammonium hydrogen sulfate with nickel chloride to form double ammonium nickel sulfate $$NiC{l}_2+2*N{H}_{\mathrm{four}}HS{O}_{\mathrm{four}}={\left(N{H}_{\mathrm{four}}\right)}_{2}Ni{\left(S{O}_{\mathrm{four}}\right)}_2\downarrow +2*HCl$$

. The solution was drained from the precipitate, the pH of the decantate was measured equal to -0.15, which corresponds to the pH of the solution is no longer an acid salt, but a solution of hydrogen chloride. The volume of decantate was 128 ml, and the weight was 133 g. The precipitate was poured into 20 ml of cold water at 6 ° C, stirred, drained, the process was repeated, after which the precipitate was dissolved in 150 g of hot water, and the pH of the solution was 2.76 at a temperature of 43 ° C.

Based on the results we make calculations for the resulting solution of hydrogen chloride: pH = -0.15 gives the concentration of H ⁺ ions, and hence hydrochloric acid 10 ^{- (- 0.15)} = 1.41 mol / l, which means 128 ml in our decantate * 1.4125 mol / L = 0.181 mol of hydrochloric acid from 0.200 moles, which could be obtained theoretically, which means a successful reaction with significant (over 90%) for industry percent yield of a solution of hydrogen chloride.

It should be noted that the real yield of hydrogen chloride is even higher, since part of the hydrogen chloride solution remained in the wet sediment (in industry it can be separated in a centrifuge) and then left with wash water. It is impossible to calculate the amount of this unaccounted hydrogen chloride directly from the pH of the solution, since when the precipitate is dissolved, double ammonium-nickel sulfate interacts with hydrogen chloride.

It should be noted that the reaction of formation of double ammonium-nickel sulfate passed without interfering side reactions (coprecipitation of acid salts) and a very pure nickel-ammonium double sulfate was obtained. We provide the following performance evaluation of precipitate: the precipitate is dissolved pH = 2,76, which gives the concentration of H ⁺ ions 10 ^{- (2.76)} = 0.0017 mole / liter, then all the precipitate dissolved in H ⁺ 150 * 0.0017 ml mol / L = 0.0026 moles of impurities. This is most likely not an impurity, but the result of an insufficient washing of the precipitate.

The resulting hydrogen chloride solution can be used in any known manner. For example, the industrial method of isolating hydrogen chloride from the resulting solution (M. Levinsky, A. Mazanko, I. N. Novikov, Hydrogen chloride and hydrochloric acid. - M: Chemistry, 1985) [8].

We do a control check confirming the possibility of obtaining gaseous hydrogen chloride. We take the resulting solution weighing 133 grams, begin to boil it: the litmus test in the pair turns blue, in the pair is hydrogen chloride. We evaporate the solution to a volume of 2-3 ml, add water to a weight of 133 grams and measure the pH of the solution equal to 1.06. We carry out the following assessment according to the characteristics of the solution: the concentration of H ⁺ ions 10 ^{- (1.06)} = 0.087 mol / L, which means that in the dissolved precipitate only H ⁺ 133 ml * 0.087 mol / L = 0.0116 moles that remained in the solution 133 ml . So, from the solution containing 0.180 moles of hydrogen chloride, 0.1684 moles of gaseous hydrogen chloride were indeed isolated.

We analyze for the sulfate ion the remaining 133 ml of the solution, precipitating the sulfate ion with barium nitrate and getting 1.22 grams of barium sulfate. This gives 0.50 grams of sulfate ion in 133 ml of solution or 0.38% impurity of sulfate ion in a solution of hydrogen chloride. According to TU 6-01-1194-79 for technical hydrochloric acid, the amount of sulfates in terms of sulfate ion should not exceed 0.8%. Impurities of the iron ion were not detected by analysis. Therefore, given that we did not obtain the concentration of hydrogen chloride required by the technical specifications, but the requirements for impurities were met, we obtained dilute hydrochloric acid.

Example 2

Double sulfate having low solubility is tested - aluminum-potassium sulfate, solubility at 0 ° C is 2.91%. The efficiency of the pair is checked: a monovalent cation with a trivalent cation. The monovalent potassium cation is tested. The trivalent aluminum cation is tested.

Aluminum chloride AlCl _{3 was} used as the chloride containing the first of the double sulfate cations; potassium hydrosulfate of KHSO _{4 was} used as the hydrosulfate containing the second of the double sulfate cations

$$AlC{l}_3+2*KHS{O}_{\mathrm{four}}=2*KAl{\left(S{O}_{\mathrm{four}}\right)}_2\downarrow +2*HCl+KCl$$

75 grams of hot water were poured into a heat-resistant glass and dissolved in it was 19.19 grams of potassium hydrosulfate of the ChDA grade, this is 0.200 moles of the reagent, the pH of the solution is 0.51, this corresponds to an acid salt solution. 75 grams of hot water were poured into a heat-resistant glass and 24.1 grams of aluminum chloride 6 of water grade H were dissolved in it, which is 0.100 moles of reagent. The resulting solutions were mixed in a heat-resistant glass. The glass was placed in a cuvette filled with an alcoholic solution and pieces of ice, and they began to cool by stirring the solution and measuring the temperature and pH of the solution. As the solution cools, the pH of the solution decreases: at 31.0 ° C, pH = 0.15, At 22.0 ° C, pH = 0.06, and precipitate formation is noticeable, at 1.8 ° C pH = -0.05, at 0.6 ° C pH = -0.09, at 0.0 ° C, pH = -0.09, further cooling loses its meaning. The rate of precipitation of the precipitate after mixing is very high, the solution becomes completely transparent in less than a minute.

Раствор с осадка слили, измерили pH декантата равный -0,09, что соответствует pH раствора уже не кислой соли, а раствора хлористого водорода. Объем декантата составил 142 мл, а вес 147 г. Вес влажного осадка составил 56 грамм.Thus, a precipitate formed in the glass as a result of the reaction of potassium hydrogen sulfate with aluminum chloride to form double potassium aluminum sulfate $$AlC{l}_3+2*KHS{O}_{\mathrm{four}}=2*KAl{\left(S{O}_{\mathrm{four}}\right)}_2\downarrow +2*HCl+KCl$$

The solution was drained from the precipitate, the pH of the decantate was measured equal to -0.09, which corresponds to the pH of the solution is no longer an acid salt, but a solution of hydrogen chloride. The volume of decantate was 142 ml, and the weight was 147 g. The weight of the wet sediment was 56 grams.

Based on the results, we make calculations for the resulting solution of hydrogen chloride: pH = -0.09 gives the concentration of H ⁺ ions, and hence hydrochloric acid 10 ^{- (- 0.09)} = 1.230 mol / l, which means 142 ml * 1.230 in our decantate mol / L = 0.175 mol of hydrochloric acid from 0.200 moles, which could be obtained theoretically, which means a successful reaction with significant (almost 90%) for industry percent yield of a solution of hydrogen chloride.

Example 3

Double sulfate with average solubility, cobalt-ammonium sulfate, is tested; the solubility at 0 ° C is 5.7%. The performance of the pair is checked: a monovalent cation with a divalent cation. Ammonium cation is tested. The bivalent cobalt cation is tested.

As the chloride containing the first of the double sulfate cations, cobalt chloride CoCl _{2 was used} ; as the hydrosulfate containing the second of the double sulfate cations, ammonium hydrosulfate NH ₄ HSO _{4 was used}

$$CoC{l}_2+2*N{H}_{\mathrm{four}}HS{O}_{\mathrm{four}}={\left(N{H}_{\mathrm{four}}\right)}_{2}Co{\left(S{O}_{\mathrm{four}}\right)}_2\downarrow +2*HCl$$

50 grams of hot water were poured into a heat-resistant glass and dissolved in it 22.99 grams of ChDA grade ammonium hydrosulfate, this is 0.200 moles of reagent, the pH of the solution is 0.52, this corresponds to an acid salt solution. 53 grams of hot water were poured into a heat-resistant glass and dissolved in it 23.50 grams of cobalt chloride 6 water grade H, this is 0.100 moles of reagent. The resulting solutions were mixed in a heat-resistant glass. The glass was placed in a cuvette filled with an alcoholic solution and pieces of ice, and they began to cool by stirring the solution and measuring the temperature and pH of the solution. As the solution cools, the pH of the solution decreases: at 3.5 ° C pH = 0.09, at 0.9 ° C pH = -0.07. At 0.0 ° C pH = -0.10 further cooling loses its meaning. The rate of precipitation of the precipitate after mixing is very high, the solution becomes completely transparent in less than half a minute.

.Thus, a precipitate formed in the glass as a result of the reaction of ammonium hydrosulfate with cobalt chloride to form double ammonium cobalt sulfate $$CoC{l}_2+2*N{H}_{\mathrm{four}}HS{O}_{\mathrm{four}}={\left(N{H}_{\mathrm{four}}\right)}_{2}Co{\left(S{O}_{\mathrm{four}}\right)}_2\downarrow +2*HCl$$

.

The solution was drained from the precipitate, the pH of the decantate was measured equal to -0.10, which corresponds to the pH of the solution is no longer an acid salt, but a solution of hydrogen chloride. The volume of decantate was 102 ml, and weight 111 g.

According to the results obtained by doing the calculations for hydrogen chloride solution: pH = -0,10 gives the concentration H ⁺ ions, and hence of hydrochloric acid 10 ^{- (- 0.10)} = 1.259 mol / l, then in our decantate 102 ml * 1,259 mol / L = 0.128 mol of hydrochloric acid from 0.200 moles, which could be obtained theoretically, which means a successful reaction with significant (over 64%, plus the solution remaining in the precipitate) for industry percent yield of a solution of hydrogen chloride.

The resulting solution of hydrogen chloride can be used to isolate hydrogen chloride industrially [8].

Example 4

Double sulphate having high solubility, magnesium-ammonium sulphate is tested, solubility at 0 ° C is 10.58%. The efficiency of the pair is checked: a monovalent cation with a divalent cation, when the divalent cation is a part of hydrosulfate. The monovalent ammonium cation in chloride is tested. The divalent magnesium cation is tested. The invariance of the production of double sulfate with respect to the exchange of cations in hydrosulfate and chloride is verified. The salting out of the double sulfate by the cation included in the ore, the magnesium ion cation, is verified. The suitability for leaching the hydrogen chloride solution obtained by salting out is examined using an example of a magnesium-containing concentrate - serpentinite of the Bazhenovsky field in Asbest. The possibility of obtaining gaseous hydrogen chloride from a solution obtained by salting out is checked.

Ammonium chloride NH ₄ Cl was used as the chloride containing the first of the double sulfate cations; magnesium hydrosulfate of Mg (HSO ₄ ) _{2 was} used as the hydrosulfate containing the second of the double sulfate cations

$$2*N{H}_{\mathrm{four}}Cl+Mg{\left(HS{O}_{\mathrm{four}}\right)}_2={\left(N{H}_{\mathrm{four}}\right)}_{2}Mg{\left(S{O}_{\mathrm{four}}\right)}_2\downarrow +2*HCl$$

50 grams of hot water was poured into a heat-resistant glass and dissolved in it was 21.80 grams of ChDA grade magnesium hydrosulfate, this is 0.100 moles of reagent, the pH of the solution is 0.51, this corresponds to an acid salt solution. 60 grams of hot water were poured into a heat-resistant glass and dissolved in it 10.70 grams of grade Ch ammonium chloride, which is 0.200 moles. The glass was placed in a cuvette filled with an alcoholic solution and pieces of ice, and they began to cool by stirring the solution and measuring the temperature and pH of the solution. As the solution cools, the pH of the solution decreases: at 14.0 ° C pH = 0.40, at 6.0 ° C pH = 0.18, at 0.0 ° C pH = 0.12, further cooling makes no sense, no precipitate or cloudiness of the solution indicating the beginning of the crystallization process. It was not possible to precipitate double sulfate having high solubility by cooling to 0 ° C. The beaker with the solution was transferred to a freezer with a temperature of -18 ° C and began to cool with periodic stirring. During mixing, ice crystals were dissolved on the walls and surface of the liquid. Three hours later, a clear solution was formed in a glass and a salt precipitate at the bottom.

Раствор с осадка слили, измерили pH декантата равный -0,18, что соответствует pH раствора уже не кислой соли, а раствора хлористого водорода. Объем декантата составил 108 мл, а вес 116,3 грамм. Вес влажного осадка составил 17,7 грамм.Thus, a precipitate formed in the glass as a result of the reaction of magnesium hydrosulfate with ammonium chloride to form double magnesium sulfate - ammonium $$2*N{H}_{\mathrm{four}}Cl+Mg{\left(HS{O}_{\mathrm{four}}\right)}_2={\left(N{H}_{\mathrm{four}}\right)}_{2}Mg{\left(S{O}_{\mathrm{four}}\right)}_2\downarrow +2*HCl$$

The solution was drained from the precipitate, the pH of the decantate was measured equal to -0.18, which corresponds to the pH of the solution, not the acid salt, but the hydrogen chloride solution. The volume of decantate was 108 ml, and the weight was 116.3 grams. The weight of the wet cake was 17.7 grams.

Based on the results we make calculations for the resulting solution of hydrogen chloride: pH = -0.18 gives the concentration of ions, and hence hydrochloric acid 10 ^{- (- 0.18)} = 1.514 mol / l, which means 108 ml * 1.514 mol / in our decantate l = 0.163 mol of hydrochloric acid from 0.200 moles, which could be obtained theoretically, which means a successful reaction with significant (81.3%) for industry percent yield of a solution of hydrogen chloride.

To check the invariance of the production of double sulfate with respect to the exchange of cations in hydrosulfate and chloride, we use magnesium chloride MgCl ₂ as the chloride containing the first of the double sulfate cations; magnesium hydrosulfate NH ₄ HSO _{4 was} used as the hydrosulfate containing the second of the double sulfate cations

$$MgC{l}_2+2*N{H}_{\mathrm{four}}HS{O}_{\mathrm{four}}={\left(N{H}_{\mathrm{four}}\right)}_{2}Mg{\left(S{O}_{\mathrm{four}}\right)}_2\downarrow +2*HCl$$

54 grams of hot water were poured into a heat-resistant glass and dissolved in it was 22.98 grams of ChDA grade ammonium hydrosulfate, this is 0.200 moles of reagent, the pH of the solution is 0.50, this corresponds to an acid salt solution. 50 grams of hot water were poured into a heat-resistant glass and 31.06 grams of magnesium chloride 6 of water grade H was dissolved in it, which is 0.153 moles. The glass was placed in a cuvette filled with an alcoholic solution and pieces of ice, and they began to cool by stirring the solution and measuring the temperature and pH of the solution. As the solution cools, the pH of the solution decreases: at 0.8 ° C pH = 0.23, at 0.3 ° C, pH = -0.25, further cooling loses its meaning. The rate of precipitation of the precipitate after mixing is very high, the solution becomes completely transparent in less than a minute.

Раствор с осадка слили, измерили pH декантата равный -0,25, что соответствует pH раствора уже не кислой соли, а раствора хлористого водорода. Объем декантата составил 112 мл, а вес 125 грамм.Thus, a precipitate formed in the glass as a result of the reaction of ammonium hydrosulfate with magnesium chloride to form double ammonium-magnesium sulfate $$MgC{l}_2+2*N{H}_{\mathrm{four}}HS{O}_{\mathrm{four}}={\left(N{H}_{\mathrm{four}}\right)}_{2}Mg{\left(S{O}_{\mathrm{four}}\right)}_2\downarrow +2*HCl$$

The solution was drained from the precipitate, the pH of the decantate was measured equal to -0.25, which corresponds to the pH of the solution is no longer an acid salt, but a solution of hydrogen chloride. The volume of decantate was 112 ml, and weight 125 grams.

Based on the results obtained, we make calculations of the obtained hydrogen chloride: pH = -0.25 gives the concentration of H ⁺ ions, and hence hydrogen chloride 10 ^{- (- 0.25)} = 1.79 mol / l, which means 112 ml * 1 in our decantate 79 mol / L = 0.199 mol of hydrogen chloride from 0.200 moles, which could be obtained theoretically, which means a successful reaction with almost 100% percent yield of hydrogen chloride.

Obviously, an extremely successful reaction was facilitated by the presence of an excess of magnesium chloride relative to the stoichiometric amount of 0.1 mol required for the double sulfate formation reaction. It was the excess of magnesium chloride that determined the salting-out effect of magnesium ion in relation to ammonium double magnesium sulfate and enhanced the precipitation of double sulfate, the solubility of magnesium double ammonium sulfate in a solution of magnesium chloride at low temperatures was negligible. To successfully precipitate magnesium-ammonium double sulfate, ammonium chloride could also be added, which would determine the salting-out effect of the ammonium ion with respect to the double ammonium-magnesium sulfate. But from the point of view of using the obtained solution of hydrogen chloride to leach magnesium-containing raw materials, this would be worse. Magnesium ion still gets into the solution when leaching magnesium containing raw materials and its presence in the original leach solution does not pollute the final product, and the ammonium ion would introduce pollution.

It should be noted that when carrying out the reaction of the formation of double sulfate having high solubility, it is necessary to add an excess of reagents to obtain a salting out effect only in the form of chloride. In the case of introducing a salting out reagent in the form of sulfate in the solution, the amount of hydrogen chloride will decrease due to the interaction of hydrogen chloride and sulfate ion to produce hydrosulfate.

To carry out leaching of magnesium-containing raw materials, we select 100 ml of a solution of hydrogen chloride in a heat-resistant glass from the resulting solution of hydrogen chloride at a concentration of 6.52%. Add fine sand 0.063-0.16 to the glass from the crushing screenings of the Bazhenovskoye deposit at the Uralasbest OJSC plant with the composition: MgO-36.40%, Al ₂ O ₃ - 1.76%, Fe ₂ O ₃ - 10.30%, SiO ₂ - 44.70%, NiO - 0.50%, Cr ₂ O ₃ - 1.90%, MnO - 0.27%, H ₂ O-3.00%, CaO - 0.52%, Na ₂ O - 0.67% in the amount of 8.9 grams, this corresponds to the stoichiometric ratio for leaching in the taken solution of hydrogen chloride. We place the glass on a heated magnetic stirrer, cover it with glass and start leaching at a temperature of 100 ° C and stirring. We measure after 10 minutes the pH of the solution is 0.06, this corresponds to leaching by 51.4%, after 20 minutes the pH of the solution is 0.18, this corresponds to leaching by 63.0%, after 60 minutes the pH of the solution is 0.57 , this corresponds to 84.7% leaching, after 150 minutes the pH of the solution is 1.52, this corresponds to 98.3% leaching. Therefore, given the high percentage of leaching with the resulting hydrogen chloride solution, the possibility of using the resulting solution as a solution for ore leaching is proved.

According to the results of example 4, it can be stated that during the precipitation of double sulfate having a high solubility, one cooling may not be enough to obtain a result in the form of a high percentage yield of a solution of hydrogen chloride. But the combined use of cooling and salting out of one of the cations that make up the double sulfate gives an excellent result even for double sulfates having high solubility.

Example 5:

Double sulfate, which has a very high solubility, is tested - sodium ammonium sulfate. The efficiency of the pair is checked: a monovalent cation with a monovalent cation. Monovalent Sodium Cation Tested

Sodium chloride NaCl was used as the chloride containing the first of the double sulfate cations, ammonium hydrosulfate NH ₄ HSO _{4 was} used as the hydrosulfate containing the second of double sulfate cations

$$2*NaCl+2*N{H}_{\mathrm{four}}HS{O}_{\mathrm{four}}={\left(N{H}_{\mathrm{four}}\right)}_{2}N{A}_2{\left(S{O}_{\mathrm{four}}\right)}_2\downarrow +2*HCl$$

20 grams of hot water were poured into a heat-resistant glass and dissolved in it 23.00 grams of ChDA grade ammonium hydrosulfate, this is 0.200 moles of reagent, the pH of the solution is 0.50, this corresponds to an acid salt solution. 30 grams of hot water were poured into a heat-resistant glass and 11.60 grams of sodium chloride of the brand dissolved in it were boiled edible salt, which is 0.200 moles of the reagent. The resulting solutions were mixed in a heat-resistant glass. The glass was placed in a cuvette filled with an alcoholic solution and pieces of ice, and they began to cool by stirring the solution and measuring the temperature and pH of the solution. After cooling the solution to 0 ° C, we see that there is no precipitate. We put the glass in the freezer with a temperature of -18 ° C, for 1 day. We get a transparent solution in a glass on top, and at the bottom a salt precipitate with insignificant inclusions of ice crystals.

Thus, a precipitate formed in the glass as a result of the reaction of ammonium hydrogen sulfate with sodium chloride to form double ammonium sodium sulfate $$2*NaCl+2*N{H}_{\mathrm{four}}HS{O}_{\mathrm{four}}={\left(N{H}_{\mathrm{four}}\right)}_{2}N{A}_2{\left(S{O}_{\mathrm{four}}\right)}_2\downarrow +2*HCl$$

The solution was drained from the precipitate, the pH of the decantate was measured equal to -0.68, which corresponds to the pH of the solution is no longer an acid salt, but a solution of hydrogen chloride. The volume of decantate was 41 ml, and the weight was 50.5 grams. The weight of the wet cake was 30.9 grams.

Based on the results we make calculations for the resulting solution of hydrogen chloride: pH = -0.68 gives the concentration of H ⁺ ions, and therefore hydrochloric acid 10 ^{- (- 0.68)} = 4.786 mol / l, which means 41 ml * 4.786 in our decantate mol / L = 0.196 mol of hydrochloric acid from 0.200 moles, which could be obtained theoretically, which means a successful reaction with significant (almost 98%) for industry percent yield of a solution of hydrogen chloride. Therefore, we obtained a large percentage of the yield of a solution of hydrogen chloride, that is, the operation was successful.

Table cation NH ₄ K Na Cs Rb Ni 0.99 3.26 Cr 3.8 18.3 Co 5.7 7.8 Al 2.05 2.91 27.24 0.21 0.72 Mg 10.58 12.35 Mn 38.7 Cu 10.27 4.84 Fe ²⁺ 11.1 16,4 Ce 1.17 Cd thirty 37 Zn 6.54 11.5

Claims (8)

1. A method of producing a double sulfate and a solution of hydrogen chloride, including the manufacture of a solution from a chloride containing one of the cations of the double sulfate and a hydrosulfate containing the second of the cations of the double sulfate, precipitation from the solution of the double sulfate, characterized in that the deposition is carried out before removal from the solution sulfate ion while obtaining a solution of hydrogen chloride. 2. The method according to claim 1, characterized in that as a hydrosulfate containing the first of the double sulfate cations, a monovalent cation hydrosulfate is preferably used, which is sodium hydrosulfate, or potassium hydrosulfate, or ammonium hydrosulfate, or rubidium hydrosulfate, or hydrosulfate cesium, and as the chloride containing the second of the double sulfate cations, magnesium chloride or aluminum chloride or heavy metal chloride, preferably nickel chloride or chromium chloride, is preferably used Or cobalt chloride or manganese chloride or copper chloride, or ferric chloride, or cadmium chloride or zinc chloride. 3. The method according to claim 1, characterized in that the precipitation from a solution of double sulfate having a low solubility is preferably carried out by cooling to a minimum solubility of the double sulfate. 4. The method according to claim 1, characterized in that the precipitation from a solution of double sulfate having low solubility is preferably carried out to obtain a solution of hydrogen chloride, which in terms of the amount of impurities corresponds to diluted technical hydrochloric acid. 5. The method according to claim 1, characterized in that the precipitation from a solution of double sulfate having an average solubility is preferably carried out to obtain a solution of hydrogen chloride, suitable for leaching ore concentrates and to obtain gaseous hydrogen chloride. 6. The method according to claim 1, characterized in that the precipitation from a solution of double sulfate having medium or high solubility is preferably carried out by cooling while salting out with an excess of chloride containing one of the cations that make up the double sulfate. 7. The method according to claim 1, characterized in that the precipitation from a solution of double sulfate having medium or high solubility is preferably carried out by cooling while salting out with an excess of chloride containing one of the cations of double sulfate, which is also in the ore, for the leaching of which the solution is produced hydrogen chloride. 8. The method according to claim 1, characterized in that the precipitation from a solution of double sulfate having high solubility is preferably carried out to obtain a solution of hydrogen chloride, suitable for the production of gaseous hydrogen chloride.