RU2476380C1 - Method of obtaining basic chloride or copper (ii) nitrate - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to technology of obtaining copper (II) salts. Method includes direct interaction of metal oxide with water solutions of hydrochloric or nitric acid with intensive mixing, including in presence of glass beads as grinding agent. Process is carried out with range of initial concentrations of acids from 0.4 to 2.7 mol/kg and mole ratio with copper (II) oxide in the range from (0.8:1) and to (1.8:1), with weight ratio of initial charge and glass beads (1:0.2)÷(1:1), at temperatures 15-50°C to the moment of process self-termination under current control over amount of accumulated copper (II) salts and acid spent on said purposes. After that, reaction mixture is separated from glass beads and filtered. Separated hard phase of reaction mixture is washed with 0.2-0.5 mol/kg solution of acid-reagent, after which it is returned for charge of repeated process. Washing solution is combined with reaction mixture filtrate. Obtained mixture is neutralised with 1.2-3.3 mol/kg water ammonia, dosed in small portions in such a way that pH does not exceed value 6.5-7.1. Product hard phase, precipitated during neutralisation, is left in contact with liquid phase for 12-24 hours, after which it is filtered, washed with distilled water and dried. Water solution of ammonium nitrate or chloride is used for other purpose.

EFFECT: method ensures high rate of obtaining and high output of main salts at room or close to them temperatures.

5 tbl, 26 ex

Description

The invention relates to a technology for the production of copper (II) salts and can be used in various fields of chemical, metallurgical, agricultural and other types of practices, in analytical control and in scientific research.

It is known that the precipitation of Cu (OH) ₂ from aqueous solutions of copper chloride, nitrate and sulfate proceeds through an intermediate stage of formation of basic salts of constant composition (V.P. Chaly. Metal hydroxides (Formation laws, composition, structure and properties). Kiev: Naukova Dumka, 1972. 159 p .; p. 53). This position is illustrated by two patented methods for producing bivalent copper chloroxide (US Pat. RF. 2121974 publ. 1998-11-20 and US Pat. RF 2161128, publ. 2000-12-27). In accordance with the first, the interaction of an acidic solution of divalent copper chloride with an aqueous suspension of calcium carbonate is carried out with constant stirring and bubbling with compressed air at 25-30 ° C. In this case, copper chloride solutions with a copper concentration of 120 g / l and pH = 0.9 are used as the initial solution, and chlorine ions that contain a peptizing agent, calcium chloride, are used as stabilizer.

In accordance with the second, copper (II) chloride is treated with a solution of aqueous ammonia in the presence of catalytic amounts of alkali metal chromates or ammonium chromate with stirring with air in the presence of nitric oxide (IV) in a ratio of 8: 1 at 20-35 ° C.

The disadvantages of these methods are:

1. As a feedstock, a copper (II) salt is used, which is a product of a deeper chemical processing than, for example, copper (II) oxide.

2. For the process, you need a catalyst, which in each case will be different, as well as a process stabilizer.

3 The process is carried out in the presence of a gaseous phase (air or a mixture of air with nitric oxide (IV) for bubbling).

4. The presence of gas bubbling requires appropriate design of the reactor, which greatly complicates the reaction apparatus.

Closest to the claimed is a method for producing basic copper (II) acetate (S. D. Pozhidaeva, T. Mayakova, A. Ivanov, D. A. Sotnikova. Intermediate stages in the corrosion damage of copper in an aqueous solution of acetic acid in the presence of copper oxide (II) in a bead mill. Practice of corrosion protection. 2010. - No. 2 (56). - S.56-59). In accordance with it, copper (II) oxide reacts with acid to form an intermediate product of basic copper (II) acetate, which mainly accumulates in the solid phase of the reaction mixture and can be separated by filtration, after which it is washed from the captured components of the liquid phase of the reaction mixture. It is noted that the separation of solid and liquid phases of the reaction mixture must be done immediately upon completion of the process. Otherwise, the basic salt continues to react with acetic acid to form a medium salt, the content of which in the product being separated increases with increasing time between the moment of termination of the process and the separation of solid and liquid phases obtained in the reaction mixture.

The disadvantages of this method are:

1. It uses acetic acid, that is, a rather weak organic acid that reacts with copper (II) oxide in a bead mill is much more easily and quickly than with the basic salt Cu (OH) OC (O) CH ₃ . It is not at all obvious that such a ratio of the rate constants of the first and second stages of the total gross process will be when replacing acetic acid with hydrochloric or nitric.

2. Under the conditions considered as a prototype of the method, the basic copper acetate Cu (OH) OS (O) CH ₃ is a poorly soluble compound and accumulates mainly in the solid phase of the reaction mixture. It is not at all obvious that basic copper (II) chloride or nitrate will have the same abnormally poor solubility in the reaction mixture. From this follows the method of isolating the product from the reaction mixture. It is clear that phase separation by simple filtration as a method of isolating the target product in the case of basic chloride or nitrate of copper (II) may not be.

3. The same can be said about the nature and amounts of stimulants used. What is clear is that they require individual selection in each case.

4. The transition from weak water-soluble acetic acid to strong water-soluble mineral acids can significantly affect the appropriate molar ratio of the reagents and the absolute values of their quantities in the initial load, the requirements for the hardware design of the process and the operational characteristics of its implementation.

The objective of the proposed solution is to select such conditions for the process of the interaction of copper (II) oxide with hydrochloric and nitric acids, which would ensure high yields and selectivities for basic salts at room and close to temperatures, as well as rates of production of basic chloride that are acceptable for practical purposes and copper nitrate (II).

This object is achieved in that the process is carried out in the presence of a liquid phase, which is an aqueous solution of hydrochloric or nitric acid in the range of initial concentrations from 0.4 to 2.7 mol / kg and a molar ratio with copper oxide (II) in the range from (0 , 8: 1) to (1.8: 1) with a mass ratio of the initial load and glass beads (1: 0.2) ÷ (1: 1) at temperatures of 15-50 ° C until the process stops during the current quantity control the accumulated salts of copper (II) and the acid spent for these purposes, after which the reaction mixture is separated from glass beads and filtered, the separated solid phase is washed with 0.2-0.5 mol / kg of a reagent acid solution and returned to the batch process, and the washing solution is combined with the filtrate of the reaction mixture, the resulting mixture is neutralized 1.2-3.3 mol / kg aqueous ammonia, dosed in small portions so that the pH does not exceed 6.5-7.1, the solid phase of the product precipitated upon neutralization is left in contact with the liquid phase for 12-24 hours, after which it is filtered, washed with distilled water and dried.

Characteristics of the raw materials used:

Copper oxide (II) according to GOST 16539-79,

Hydrochloric acid GOST 857-95,

Nitric acid GOST 701-89,

Distilled water according to GOST 6709-72,

Ammonia water GOST 3760-79.

The process of the claimed method is as follows. In a vertical type bead mill with a high-speed paddle mixer, the calculated amounts of glass beads, distilled water, concentrated mineral acid and copper (II) oxide are introduced. They include mechanical stirring and conduct the process at 15-50 ° C and control the progress by sampling and determining the contents of the accumulated product and the consumed acid in them. As soon as the contents of the accumulated product and the consumed acid reach their maximum, equal to each other and subsequently practically unchanged values, the process is stopped. The reaction mixture is separated from the glass beads by filtration through a mesh and then filtered. The separated solid phase is washed with 0.2-0.5 mol / L mineral acid solution, and then returned to the loading of the second process. And the liquid phase (filtrate + wash solution) is subjected to neutralization with a concentrated solution of ammonium hydroxide under pH-metric control so that throughout the course of neutralization the pH does not exceed 7, and in the end it is in the range of 6.5-7.1. The precipitated solid phase is left for structuring for 12-24 hours, and then filtered. The precipitate is washed with distilled water, filtered again, and then dried, and the mass and quality characteristics are determined. The filtrate is subjected to analysis for the content of dissolved copper (II) compounds and is used for its intended purpose.

Example No. 1.

In a thick-walled glass beaker, like the case of a vertical type bead mill with an internal diameter of 52.3 mm and a height of 153 mm, with a flat bottom and a high-speed (1560 rpm) paddle mixer with a 51 × 49 × 3.1 mm pad of a PCB, 120 g are loaded glass beads, 9.6 g of copper (II) oxide, 98.4 g of distilled water and 12 g of concentrated (10 mol / kg) hydrochloric acid. The case of the bead mill is placed in a socket for it in the frame frame, connected to a cover made of textolite, in which there is an stuffing box and pockets for a sampler and temperature measurement. After that, the mill is properly fixed in the designated socket, the operation of the mechanical stirrer is checked manually, and a temperature-stabilizing water bath is brought in from below. Turn on mechanical mixing and this moment is taken as the beginning of the process. The temperature in the reaction zone is 21 ° C. The process is conducted in such a way that it does not change by more than 2 ° C in one direction or another. During the process, samples of the reaction mixture are taken, in which the content of the Cu ²⁺ product is determined, as well as the amount of acid remaining and consumed at the time of sampling. For this process received:

The time from the start of the process, min The content of Cu ²⁺ product in the reaction mixture (PC), mol / kg The content of HCl in PC, mol / kg The amount of spent HCl on the formation of the product, mol / kg 5 0.39 0.61 0.39 10 0.47 0.53 0.47 fifteen 0.49 0.51 0.49 twenty 0.51 0.49 0.51 thirty 0.51 0.49 0.51 40 0.51 0.49 0.51

Since, starting from 20 min, the composition of the reaction mixture remains unchanged, the process is stopped. To do this, turn off the mechanical stirring, set aside the temperature-maintaining bath, remove the bead mill in the socket of the frame frame, disconnect the lid from the housing, remove the housing and transfer it to the filtering unit. First, glass beads are separated on a mesh with mesh sizes of 0.3 × 0.3 mm as a filter membrane. It is carefully removed from the net and returned to the mill body. The apparatus is reassembled, 30 g of 0.5 mol / kg of hydrochloric acid are introduced, mechanical stirring is switched on, and beads are washed for 3 minutes, as well as the surfaces of the casing, the blades of the mechanical stirrer and its shaft from the remnants of the reaction mixture. The washed beads are repeatedly separated from the wash liquid, which is collected in a separate container and used in the further processing of the reaction mixture.

The PC suspension is filtered using vacuum, the remaining solid phase is transferred to the filter using the filtrate, the precipitate is thoroughly washed with the previously obtained washing liquid, filtered again, carefully squeezed, removed from the filter and dried, and then sent to the loading process again. And the filtrate combined with the washing liquid is sent to neutralize the hydrochloric acid contained in it with 2.5 mol / kg aqueous ammonia. Neutralization is carried out fractionally with vigorous stirring and constant pH control. The latter along the way should not exceed 7. The neutralization is stopped at pH 6.85. The resulting suspension of the product is left for 20 hours in order to facilitate subsequent filtration of the solid phase of the product. The filtration itself is carried out under vacuum, followed by washing the filter cake with distilled water, removing from the filter and drying in air to constant weight.

In this example, a dry product of 10.69 g was obtained. The atomic adsorption determination of copper in it is 54.7 ± 0.1%, which corresponds to the gross formula of Cu (OH) Cl. The degree of conversion of the reactants to the product is ~ 76%. Product selectivity ~ 99%.

Examples No. 2-10.

Reactor, loading mass, initial reagents, solvent of the liquid phase, loading sequence, operational scheme of the process and monitoring it, separating glass beads from the resulting reaction mixture, separating the phases of the latter and isolating the target product from them, as well as working with it are similar to those described in example 1. It differs in initial dosages of copper (II) oxide and hydrochloric acid, the molar ratio of oxide: acid in the initial reaction mixture, the mass ratio of the reaction mixture and glass bead RA, the temperature of the process, the concentration of hydrochloric acid to wash the solid phase of the reaction mixture and ammonia used to neutralize unreacted acid, as well as the duration of storage of the suspension of the product before filtering and subsequent processing. These differences and other characteristics are summarized in the table. (PC is a reaction mixture).

Download and process specifications Example No. 2 3 four 5 6 7 8 9 10 Dosage of copper oxide (II), mol / kg 0.5 0.5 0.8 1,0 1,0 1,0 1,2 1,5 1,5 The content of hydrochloric acid in the initial load, mol / kg 0.4 0.9 0.8 0.8 1.3 1,6 1,2 1,2 2.7 The molar ratio of CuO to HCl in the initial load 1: 0.8 1: 1.8 1: 1 1: 0.8 1: 1.3 1: 1.6 1: 1 1: 0.8 1: 1.8 The mass ratio of glass beads and the rest of the load 1: 1 1: 1 0.9: 1 0.4: 1 0.6: 1 0.2: 1 1: 1 1: 1 1: 1 PC temperature, ° C: initial at the end of the process fifty 45 37 28 25 23 21 19 fifteen 48 47 37 26 26 23 twenty 21 fifteen The duration of the process until self-termination, min 25 fourteen eleven 23 16 13 23 31 37 The degree of conversion of CuO at the time of self-termination of the process,% 54 59 58 68 85 97 63 56 71

Table continuation Download and process specifications Example No. 2 3 four 5 6 7 8 9 10 The amount of product separated in the form of a filtrate, mol / kg 0.25 0.28 0.41 0.51 0.79 0.94 0.66 0.73 0.97 The concentration of hydrochloric acid in the solution for washing the solid phase PC, mol / kg 0.2 0.3 0.4 0.5 0.3 0.5 0.4 0.3 0.5 Amount of solution
hydrochloric acid for washing the solid phase of the PC,% by weight of the initial load 45 25 thirty 40 40 25 thirty 40 25 The amount of product received from the solid phase PC, mol / kg 0,020 0.015 0,054 0.170 0,060 0,030 0,096 0,110 0,095 The concentration of the solution of NH ₄ OH used to neutralize the acid in the filtrate and the wash solution, mol / kg 1,2 2,5 2.0 2.1 2,5 3.0 3,1 3.3 3.3 Final pH during neutralization of the filtrate and wash solution 6.5 6.8 6.9 6.5 7.1 6.9 7.0 6.9 7.1 Duration of structuring of the solid phase of the product precipitated during neutralization of acid before filtration 12 16 13 19 23 fifteen fourteen twenty 24

Table continuation Download and process specifications Example No. 2 3 four 5 6 7 8 9 10 The mass of the product after separation of the solid phase, washing with distilled water and drying in air, g 3.47 3.91 6.19 9.21 11.39 13.06 10.17 11.34 14.29 The yield of solid product,% of theoretical 92.0 94.9 95.4 96.8 96.0 96.3 96.5 96.6 96.0 The copper content in the product according to the results of atomic adsorption determination,% 52.8 53.6 54.5 54,4 55.1 55.1 54.8 54.7 58.2

Examples No. 11-17.

The mass of the load, the starting reagents, the solvent of the liquid phase, the sequence of loading of the components, the operational scheme of the process and monitoring it, separation of glass beads from the resulting reaction mixture, separation of the phases of the reaction mixture and the product isolates from them are similar to those described in example 1. They differ in dosage reagents, the molar ratio of CuO: HCl, the type of reactor used, the intensity of mechanical stirring in it, the concentrations and quantities used for washing phase PC and neutralizing unreacted acid solutions of HCl and aqueous ammonia. These differences and other characteristics are summarized in the table.

Download and process specifications Example No. eleven 12 13 fourteen fifteen 16 17 Dosage of copper oxide (II), mol / kg 0.92 0.92 0.92 0.92 0.4 2.0 3.3 The content of hydrochloric acid in the initial load, mol / kg 0.92 0.92 0.92 0.92 0.50 7.00 5.94

Table continuation Download and process specifications Example No. eleven 12 13 fourteen fifteen 16 17 The molar ratio of CuO to HCl in the initial load 1: 1 1: 1 1: 1 1: 1 1: 1.25 1: 3,5 1: 1.8 Reactor conical flask on MB Bead Mill Body Bead mill Characterization of the intensity of mixing PC in the reactor agitator rotation speed 2960 rpm shaking frequency ~ 2Hz The number of revolutions of the paddle mixer in min 1560 PC temperature, ° C: initial at the end of the process 21 21 21 21 16 25 23 21 22 21 23 17 thirty 28 The duration of the process until self-termination, min 65 43 41 10 twenty eighteen eighteen The degree of conversion of CuO at the time of self-termination of the process,% 53.0 61.0 64.0 81.0 39.5 98.5 72.0 The amount of product separated in the form of a filtrate, mol / kg 0.46 0.50 0.51 0.61 0.13 0.27 0.34 The concentration of hydrochloric acid in the solution for washing the solid phase PC, mol / kg 0.3 0.3 0.3 0.3 0.2 0,0 0,0 The amount of hydrochloric acid solution for washing the solid phase of the PC,% by weight of the initial load 35 35 35 35 25 twenty twenty The amount of product received from the solid phase PC, mol / kg 0,03 0.06 0.08 0.14 0.02 0.42 0.51

Table continuation Download and process specifications Example No. eleven 12 13 fourteen fifteen 16 17 The concentration of the solution of NH ₄ OH used to neutralize the acid in the filtrate and the wash solution, mol / kg 2,3 2,5 2,5 2,5 1.8 3.0 3.2 Final pH during neutralization of the filtrate and wash solution 6.9 7.0 7.0 6.8 6.7 7.0 6.9 Duration of structuring of the solid phase of the product precipitated during neutralization of acid before filtration 24 24 24 24 12 eighteen twenty The mass of the product after separation of the solid phase, washing with distilled water and drying in air, g 6.31 7.55 7.93 9.98 2.02 3.77 + 17.23 4.35 + 20.14 The yield of solid product in% of theoretical Not determined 93.0 96.2 96.4 95.8 91.4 The copper content in the product according to the results of atomic adsorption determination,% 58.4 52,4 53.6 54,2 63,4 61.3 65,2

(MB - mechanical shaker)

Example No. 18.

Reactor, loading and loading masses of CuO, molar ratio oxide: acid in loading, loading sequence, step-by-step process flow diagram and monitoring, temperature at the beginning and at the end, separation of glass beads from the obtained reaction mixture, phase separation of the reaction mixture and isolation product from them, as well as working with it are similar to those described in example 1. It differs in the use instead of hydrochloric nitric acid. Its loading in the form of 8.9 mol / kg of an aqueous solution of 14.3 g. The loading of distilled water 96.1 g. Kinetic characteristics of the process:

The time from the start of the process, min The content of Cu ²⁺ product in the reaction mixture (PC), mol / kg The content of HNO ₃ in PC, mol / kg The amount of spent HNO ₃ on the formation of the product, mol / kg 5 0.40 0.60 0.40 10 0.46 0.54 0.46 fifteen 0.50 0.50 0.50 twenty 0.56 0.44 0.56 thirty 0.56 0.44 0.56 40 0.56 0.42 0.58

The dry product obtained 10.42 g or 96.4% of the calculated value. The degree of conversion of the reactants to the product is 63%. Product selectivity ~ 99%. The copper content in the solid product according to the results of atomic adsorption determination of 45% by weight, which corresponds to the gross formula Cu (OH) NO ₃ .

Examples No. 19-26.

The reactor, the nature of the reagents, the mass and sequence of loading, the operational scheme of the process and monitoring it, separating glass beads from the resulting reaction mixture, separating the phases of the latter and isolating products from them, as well as working with the product are similar to those described in Example 18. They differ in the initial dosages of copper (II) oxide and nitric acid, molar ratios of oxide: acid in the initial reaction mixture, mass ratios of glass beads and loading, the temperature of the process, concentrations of nitric acid to wash the solid phase of the reaction mixture and ammonia to neutralize unreacted acid, as well as the duration of storage of the suspension of the product before filtering and subsequent processing. These differences and other characteristics are summarized in the table.

Download and process specifications Example No. 19 twenty 21 22 23 24 25 26 Dosage of copper oxide (II), mol / kg 0.50 0.85 0.85 0.85 0.85 0.85 1,5 1,5 The content of nitric acid in the original PC, mol / kg 0.75 0.68 0.85 1.06 1.06 1.28 1.20 2.70 The molar ratio of CuO and HNO ₃ in the initial load, mol / mol 1: 1,50 1: 0.8 1: 1 1: 1.25 1: 1.25 1: 1,50 1: 0.8 1: 1.8

Table continuation Download and process specifications Example No. 19 twenty 21 22 23 24 25 26 The mass ratio of glass beads and the rest of the load 1: 1 0.8: 1 0.7: 1 1: 1 0.7: 1 1: 1 1: 1 1: 1 PC temperature, ° C: initial at the end of the process 33 fifty fifty thirty 28 34 twenty fifteen 35 48 48 29th thirty 34 twenty fifteen The duration of the process until self-termination, min 25 fifteen fifteen fifteen fifteen twenty 35 fifty The degree of conversion of CuO at the time of self-termination of the process,% 54 48 53 60 59 67 71 77 The amount of product separated in the form of a filtrate, mol / kg 0.24 0.36 0.39 0.45 0.44 0.50 0.97 1.00 The concentration of nitric acid in the solution for washing the solid phase PC, mol / kg 0.2 0.3 0.3 0.2 0.2 0.4 0.5 0.5 The amount of HNO ₃ solution for washing the solid phase of the PC,% by weight of the initial load thirty thirty thirty 35 35 40 40 40 The amount of product received from the solid phase PC, mol / kg 0,03 0.05 0.06 0.06 0.06 0,07 0.10 0.16 The concentration of the solution of NH ₄ OH used to neutralize the acid in the filtrate and the wash solution, mol / kg 2,3 2,3 3,1 3,1 3,1 3,1 3,1 3,1 Final pH during neutralization of the filtrate and wash solution 6.5 6.8 6.9 7.1 6.9 6.9 7.0 7.1 Duration of structuring of the solid phase of the product precipitated during neutralization of acid before filtration 24 17 16 12 fourteen eighteen twenty 22

Table continuation Download and process specifications Example No. 19 twenty 21 22 23 24 25 26 The mass of the product after separation of the solid phase, washing with distilled water and drying in air, g 4,56 6.83 7.58 8.55 8.35 9.37 17.5 19.0 The yield of solid product,% of theoretical 98.4 97.5 98.1 97.7 97.0 95.8 95.7 95.9 The copper content in the product according to the results of atomic adsorption determination,% 52.1 45.1 44.6 44.8 44.9 46.7 45,2 53,2

The positive effect of the proposed solution is that:

1. In the proposed solution, there is a 100% conversion of the masses of the starting reagents into the target products Cu (OH) Cl and Cu (OH) NO ₃ , i.e. into the basic salts of the simplest structure, which at the given time are obtained by electrochemical and other, much more complex and multi-stage methods.

2. The proposed solution has fairly wide ranges of variation of the initial contents of copper oxide, working acid and the molar ratio of the amounts of these reagents in the initial load.

3. The hardware design for its implementation is quite simple and is represented by a wide assortment (from a bead mill to an apparatus with intensive mechanical stirring and further to an apparatus based on a mechanical shaker platform).

4. The process proceeds quickly and selectively at room temperatures; it has no strongly exothermic stages, which greatly simplifies the maintenance of a given temperature regime.

5. The process ceases, which excludes the search for reliable criteria for finding the moment of termination of the process.

6. Isolation of the product is simple, and the accompanying products resulting from this have their own areas of rational use.

Claims (1)

A method of obtaining a basic chloride or copper (II) nitrate by direct interaction of a metal oxide with aqueous solutions of hydrochloric or nitric acid with vigorous stirring, including in the presence of glass beads as a grinding agent, characterized in that the process is carried out in the presence of a liquid phase, which is an aqueous solution of hydrochloric or nitric acid in the range of initial concentrations from 0.4 to 2.7 mol / kg and a molar ratio with copper oxide (II) from 0.8: 1 to 1.8: 1 with a mass ratio of the initial loadglass beads 1: 0.2 ÷ 1: 1 at temperatures of 15-50 ° C until the process stops during the current monitoring of the amount of accumulated copper (II) salts and the acid spent for these purposes, after which the reaction mixture is separated from the glass beads and filtered , the separated solid phase is washed with a 0.2-0.5 mol / kg solution of an acid reagent and returned to the batch of the repeated process, and the washing solution is combined with the filtrate of the reaction mixture, the resulting mixture is neutralized with 1.2-3.3 mol / kg with aqueous ammonia dosed in small portions in such a way way that the pH value does not exceed the 6.5-7.1, precipitated during the neutralization a solid phase product is left in contact with the liquid phase for 12-24 hours, then filtered, washed with distilled water and dried.