RU2376278C1 - Manganese (ii) fumarate synthesis method - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method of synthesis of manganese (II) fumarate through direct reaction of metal with acid is presented. The process is carried out in a vertical type bead mill with mass ratio of beads to the reaction mixture equal to 1:1, and the liquid phase is a solution of fumaric acid in an organic solvent with content of acid of 0.70-1.80 mol/kg. Manganese is taken in stoichiometric amount with acid or in deficiency of up to 5%. The process is started by loading the liquid phase solvent and acid and preparation of the acid solution in a bead mill, after which metal is loaded and the process is carried out at temperature ranging from 25 to 35°C while preventing spontaneous increase of temperature through forced cooling and controlling through sample taking and determination of manganese salt in the samples and residual amount of acid until attaining values close to calculated values during quantitative conversion of the reagent in deficiency. After that stirring and cooling are stopped. The suspension of the reaction mixture is separated from the glass beads, cooled to temperature between 5.2 and 6.2°C and filtered. The filtering residue is washed with the liquid phase solvent, cooled to approximately the same temperature, and taken for purification by recrystallisation. The filtrate and the washing solvent are returned to the repeated process.

EFFECT: method is easy to implement, the end product can be easily separated and there are no auxiliary materials which contaminate the obtained product.

2 cl, 11 ex

Description

The invention relates to a technology for producing salts of manganese (II) and organic acids and can be used in various fields of chemical and other types of practice, in analytical control and during research.

The literature describes the possibility of direct interaction of carboxylic acids, including fumaric, with manganese in the presence of most often the organic liquid phase and certain stimulating additives (S.D. Pozhidaeva, A. Ivanov, T. A. Mayakova, I. V. Pakhomova, I.A. Tychinskaya, Some Macrokinetic Characteristics of the Direct Interaction of Carboxylic Acids with Manganese in Organic Media in a Bead Mill, Bulletin of the Kursk State Technical University, 2008. No. 2 (23), pp. 45-51). The process is carried out in a vertical type bead mill with glass beads as a grinding agent in a mass ratio with a loading of the initial reaction mixture of at least 1: 1. However, even in such cases, the quantitative conversion of the reagent in a deficiency to a salt product is most often not achieved.

Another disadvantage of this option is that in the absence of additional, and significant and diverse information, it cannot be formed into a method for producing a specific salt of manganese and carboxylic acid, including manganese fumarate.

Closest to the claimed is a method for producing iron (II) fumarate (Patent BE 658067. Procédé de préparation du sel anhydre de fer bivalent l'acide fumarique. Pub. 04/30/1965), in accordance with which anhydrous iron (II) fumarate is obtained by the interaction metallic iron with an excess of fumaric acid at elevated temperatures in the aquatic environment in the absence of air access.

The disadvantages of this method are:

1. In a series of stresses, manganese is located noticeably to the left of iron, which determines the possibility of its easier interaction with carboxylic acid in comparison with iron. Therefore, the conditions of the process associated with this factor in the case of manganese should be noticeably different with respect to those described in the known method for iron.

2. In salts, the bivalent state is the dominant valence state of manganese. For iron, on the contrary, trivalent. Most likely, the condition indicated in the well-known solution to carry out the process without air access when implementing a similar process variant with manganese is not necessary.

3. There is no reason to believe that the aqueous medium used in the well-known solution will be acceptable, not to mention the best, when producing manganese salt.

4. There is no reason to consider the acceptability in obtaining the manganese salt of the temperature regime for the production of iron (II) fumarate.

5. Manganese fumarate and iron (II) fumarate are significantly different in their physical characteristics, including solubility in different environments. This determines significant differences in strength, brittleness, adhesion characteristics, ability to soften and liquefy, etc. blocking the surface of the metal deposits of these salts, as well as differences in the phase states of the reaction mixtures and the dominant accumulation phase of the target salt product. Hence the significant differences in the methods and operations of product isolation and processing of reaction mixtures in general.

The objective of the proposed solution is to select such conditions for the direct interaction of manganese with fumaric acid, which would ensure practically quantitative conversion of the metal into salt with a stoichiometric ratio of reagents or with a small excess of carboxylic acid, as well as product accumulation mainly in the form of a solid phase of suspended particles separated from the rest of the reaction mixture by filtration or sedimentation.

The problem is solved in that the process is carried out in a vertical type bead mill with a ratio of the mass of glass beads and the reaction mixture loading 1: 1, taking a solution of fumaric acid in an organic solvent with an acid content of 0.70-1.80 mol / as the liquid phase of the loading kg, manganese is dosed in a quantity stoichiometric with acid or in a deficiency up to 5%, the process begins with loading the solvent of the liquid phase and acid, as well as partial preparation of the acid solution in a working bead mill, after which they load the metal and conduct the process in the temperature range of 25-35 ° С while restraining the spontaneous temperature increase using forced cooling and controlling by sampling and determining the contents of manganese salt and residual acid in them until they reach values close to the calculated ones when the reagent is quantitatively converted to a lack of values, after which stirring and cooling are stopped, the suspension of the reaction mixture is separated from glass beads, cooled to a temperature of 5.2-6.2 ° C and filtered, the filter cake is washed cooled to approximately the same temperature, the solvent and the liquid phase is sent to purification by recrystallization, and the filtrate and the washing solvent is recycled to the second process. In this case, n-butyl, iso-butyl, iso-amyl alcohols and ethyl cellosolve are used as a solvent of the liquid phase.

Characteristics of the raw materials used

Reactive manganese according to GOST 6008-90.

Fumaric acid according to TU 6-09-4008-75.

n-Butyl alcohol according to GOST 6006-78.

iso-butyl alcohol according to GOST 9536-79.

iso-amyl alcohol according to GOST 5830-70.

Ethyl cellosolve according to GOST 8313-88.

The process of the claimed method is as follows. In a bead mill of the vertical type with a high-speed paddle mixer and glass beads as a grinding agent in a mass ratio with the loading of the reaction mixture 1: 1, the calculated amounts of the solvent of the liquid phase and fumaric acid are loaded. Mechanical stirring is switched on and fumaric acid solution is prepared for some time. 100% dissolution of the acid during this period is not required. Therefore, this operation is completed after a certain experimentally selected time. At this point, the calculated amount of manganese metal is charged, and the reactor vessel is placed in a cooling bath. All this is done without stopping the stirring of the reaction mixture. By adjusting the intensity of the reaction heat removal, the temperature is set and stabilized at a predetermined level. During the process, samples of the reaction mixture are taken, in which the amount of accumulated manganese (II) salt and the content of unreacted acid are determined. Upon reaching the expected values of these characteristics, the process is stopped, the cooling bath is removed, the reaction mixture is separated from glass beads, which are returned to the reactor, where it, the stirrer, and the walls of the reactor vessel are washed with a liquid phase solvent cooled to a temperature of ~ 6 ° C and lower from the residues of the reaction mixture .

After cooling to 5.2-6.2 ° C and below, the reaction mixture is filtered, the filter cake washed with solvent from the reactor, then removed from the filter and sent for purification by recrystallization. And the filtrate and wash solvent are returned to the loading of the repeated process.

Example No. 1

In a vertical type bead mill with a glass case in the form of a glass with an inner diameter of 53.7 mm and a height of 127 mm and a high-speed (2500 rpm) vane-type mechanical stirrer with a blade size of 51 × 56 mm from Plexiglas 4.5 mm thick, with 100 g of glass beads, 81.2 g of n-butyl alcohol and 12.76 g of fumaric acid are successively charged with a reflux condenser at the outlet of the gas space and a liquid cooling bath. Mechanical stirring is turned on and an acid solution is prepared for 10 minutes. Next, a liquid cooling bath is brought in such a way that at least 80% of the height of the reactor vessel is immersed in the bath, a flow of cooling water is supplied and, without stopping mixing, 6.04 g of manganese metal are introduced. This moment is taken as the beginning of the process, which during this period develops at maximum speed. The process is exothermic, which determines the temperature increase of the reaction mixture. By regulating the intensity of the forced heat sink, the temperature is stabilized at 32 ± 1 ° C, which is maintained during the redox process.

During the process, using a special sampler inserted into the corresponding socket in the reactor lid, samples of the reaction mixture are taken, in which the content of manganese fumarate and the remaining acid are determined. It turned out that 25, 50, 75 and more than 98% degrees of conversion of manganese and acid (loaded in a stoichiometric ratio) were achieved in 5, 14, 21 and 53 minutes. Upon receipt of the last time characteristic, the process is stopped, for which mechanical stirring is stopped and the cooling bath is removed.

The reactor is disconnected from the lid, removed from the frame frame, where it is always in the same position, and the contents are transferred to a funnel with a grid with dimensions of 0.3 × 0.3 mm. Glass beads are separated on a grid and returned to the reactor, which is again connected to the lid and placed in its place in the frame frame. Then 45 g of n-butyl alcohol cooled to 6.5 ° C are introduced, mechanical stirring is switched on, and the stirrer blades, reactor vessel and beads are washed from the reaction mixture for 5 minutes. The beads washed in this way are separated from the washing solvent and the reaction mixture washed with them is again and further sent to download a second experiment.

After the initial separation of the beads, the reaction mixture was cooled to 6 ° C and filtered. The filter cake is washed with a cooled solvent after removing the residual reaction mixture on the surfaces of the mixer, its shaft, reactor walls and glass beads, after which it is somewhat dried in the air flow, removed from the filter and sent for purification by recrystallization. And the filtrate is combined with a washing solvent and sent to download a second process.

The yield of the product without taking into account losses with the return of the salt product with the filtrate and washing solvent to the repeated process and during purification was 0.108 mol. The degree of conversion of the reactants to the separated solid product is 94%.

Examples No. 2-11

The reactor, reagents, loading mass, the procedure for loading, carrying out the process and separating the reaction mixture, the duration of preparation of the acid solution, monitoring during the process and determining the moment of its termination are similar to those described in example 1. They differ in the initial acid content, the stoichiometric metal deficiency, the nature of the used solvent, the temperature of the process, the temperature of the reaction mixture during filtration and the temperature of the washing solvent. These differences and the results are summarized in table. (PC - reaction mixture, n-BS, i-BS, i-AS and EC - n-butyl, iso-butyl, iso-amyl alcohols and ethyl cellosolve.)

Characteristics of loading, process and product release Example No. 2 3 four 5 6 7 8 9 10 eleven the content in the initial PC, mol / kg - fumaric acid 0.70 0.95 1.25 1,50 1.80 1.80 1.05 1.05 1.40 1.05 - manganese 0.70 0.95 1.25 1,50 1.76 1.71 1.05 1.05 1.33 1.05 liquid solvent n-bs n-bs n-bs n-bs n-bs n-bs i-bs i-speaker i-speaker EC stabilized temperature of the process (± 1 ° C) 25 27 29th 33 35 35 32 thirty 34 28 time (min) to achieve the degree of conversion of manganese into a salt product 0.25 fourteen 5 5 5 6 6 8 fourteen 12 fifteen 0.50 thirty eighteen 13 10 12 12 29th 45 39 thirty 0.75 48 thirty 24 21 thirty 29th 76 71 62 70 0.98 84 66 79 88 105 102 118 111 115 121 washing solvent,% by weight of PC 40 42 43 45 fifty fifty 43 41 45 42 the temperature of the reaction mixture at the time of filtration, ° C 5,4 5.7 5.5 5.2 6.0 6.1 5,4 6.2 6.1 5.5 temperature of the cooled washing solvent, ° C 6.3 6.4 5.9 6.0 6.2 6.3 5.8 5,6 6.3 5.8 the product yield without taking into account losses with the return of the filtrate and the washing solvent and during purification,% of theory. 0.69 0.93 1.23 1.48 1.73 1.68 1,03 1,03 1.31 1,03 the degree of conversion of the reagent in the lack of separated solid product,% of theory. 89 92 95 95 96 96 95 96 97 95

The positive effect of the proposed solution is:

1. In the proposed solution, the highest of all possible options, the transfer of the mass of the starting reagents in the mass of the target product. A related product is hydrogen, the molecular weight of which is small, which does not require its disposal, is not a pollutant of the environment, nor the target product.

2. Used solvents for the liquid phase are available and repeatedly returned to the repeated process.

3. The product accumulates mainly in the solid phase and is easily separated by simple filtration.

4. In this decision, there are no auxiliary substances that would not contribute their mass to the mass of the target product and at the same time to some extent pollute the target product.

5. The hardware design of the process is simple and is not boiler inspection.

Claims (2)

1. The method of producing manganese (II) fumarate by direct interaction of the metal with acid, characterized in that the process is carried out in a vertical type bead mill with a mass ratio of beads and the reaction mixture loading of 1: 1, a solution of fumaric acid in organic is taken as the liquid phase of the loading a solvent with an acid content of 0.70-1.80 mol / kg, manganese is dosed in a quantity stoichiometric with acid or in a deficiency of up to 5%, the process begins with loading the solvent of the liquid phase and acid and preparing the solution acid in a working bead mill, after which the metal is loaded and the process is carried out in the temperature range of 25-35 ° С while the temperature is spontaneously controlled by forced cooling and controlled by sampling and determining the contents of manganese salt and residual acid in them until they are close to the calculated when the reagent is quantitatively converted to a lack of values, after which stirring and cooling are stopped, the suspension of the reaction mixture is separated from glass beads, cooled to a temperature perature 5,2-6,2 ° C and filtered, the filter cake was washed with chilled to approximately the same temperature, the solvent and the liquid phase is sent to purification by recrystallization, and the filtrate and the washing solvent is recycled to the second process. 2. The method according to claim 1, characterized in that as the solvent of the liquid phase take n-butyl, iso-butyl, iso-amyl alcohols and ethyl cellosolve.