RU2314285C2 - Basic iron (iii) acetate producing method - Google Patents

Abstract

FIELD: salts of iron and organic acid producing processes, namely production of salt of iron (III) and acetic acid.

SUBSTANCE: method is realized by relation of metallic iron with acetic acid at presence of oxidizing agent; using molecular iodine, iron oxides such as Fe₂O_3, Fe₃O₄ and oxygen of air as oxidizing agent for converting impurity of iron (II) acetate to basic iron (III) acetate. Process is performed in beads mill at temperature 80°C and at mass relation of liquid charge and glass beads 1 : 1. Iron is used in the form of shell abutted to lateral surface of reactor housing. Initial molar relation of iron oxide and iodine is 10 : 1. Molar relation of acetic acid, its anhydride and iron oxide is in range 100 : (2 - 5.99) : (2 - 2.5). In time moment of practically complete consumption of iron oxide, solid phase of reaction mixture is taken off by filtering. Simultaneously consumed reagents are replenished and filtrate is returned to reactor for repeating process. Number of processes to be repeated is no more than 5. At second stage residues of iron (II) salt are after-oxidized to basic iron (III) acetate due to drying up taken off solid phase of product in filter by means of blowing air at environmental temperature. Preferably, hematite, γ-oxide or minimum is used as Fe₂ O ₃ and magnetite and Fe₃O₄ x 4H₂O is used as Fe₃ O_4.

EFFECT: simplified process, usage of available reagents.

3 cl, 9 notes, 2 tbl

Description

The invention relates to a technology for the production of salts of acetic acid, in particular basic iron (III) acetate, and can be used in various industries, as well as in laboratories in analytical and applied chemistry.

It is known that in the environment of acetic acid, molecular iodine oxidizes iron with the formation of iron (II) and iron (III) salts (Ivanov AM, Altukhov S.P., Filimonova S.V. Some ways of consuming iron in solutions of iodine in low molecular weight fatty acids and assessment of their competitive ability // Bulletin of the Kursk State Technical University. Kursk, 2003, No. 1 (10). S.59-63). On the other hand, iron (III) oxides oxidize iron (II) iodide with the release of molecular iodine capable of reacting with iron (Ivanov AM, Altukhov S.P., Filimonova S.V. Some patterns of iron oxidation by molecular iodine, as well as iron iodides ( II, III) and potassium by iron (III) oxides in organic media under vigorous stirring // Collection of materials of the V international scientific and technical conference "Medical and Environmental Information Technologies - 2002". Kursk: Publishing House of the Kursk State Technical University -ta, 2002. P.173).

These two processes proceed at noticeably different temperatures and therefore are not mechanically combined locally or in time.

Closest to the claimed is a method of producing basic indium formate or acetate (as USSR AS No. 454198), in accordance with which acetic acid is reacted with a metal in the presence of hydrogen peroxide with periodic heating to 80-100 ° C and subsequent product isolation by evaporation of a solution containing rather large amounts of water and acetic acid.

The disadvantages of this method are:

1. The use of an aqueous solution of hydrogen peroxide as an oxidizing agent, which determines the release of the target product by evaporation, which is a rather energy-intensive and lengthy independent process (stage).

2. The model of this process cannot be extended to iron, since iron (III) salts are very effective catalysts for the homolytic decomposition of hydrogen peroxide, which determines the large unproductive losses of this oxidizing agent.

3. Iron easily corrodes to form oxides on its surface. Water and oxygen contribute to this process. Therefore, the target product will be contaminated with oxides, which will require additional purification.

4. The main source of the cation of the target salt is a metal that has to be preliminarily obtained and properly purified from impurities. It would be highly desirable for the production of an acetic acid salt to use at least partially the more accessible metal compounds, and even better the natural origin, for example oxides.

The objective of the proposed solution is to obtain basic iron (III) acetate with the simultaneous use of not only iron but also its oxides Fe ₂ O ₃ and Fe ₂ O ₄ as a source of cation, as well as to eliminate the energy-intensive and lengthy stage of evaporation during the isolation of the target product.

The problem is achieved in that the process of obtaining the product by the interaction of iron with acetic acid is carried out in two stages, differing in the nature of the oxidizing agent used. At the first stage, iron oxide Fe ₂ O ₃ or Fe ₂ O ₄ and molecular iodine in a molar ratio of 10: 1 are taken as the oxidizing agent, and the process is carried out at 80 ° C in a vertical type bead mill with glass beads as an oxide grinding agent in the mass ratio with the liquid phase of the load 1: 1, with a high-speed mechanical stirrer and with a reflux condenser in the absence of air flow through the gas space of the reactor, but without special restrictions regarding isolation of this space from the atmosphere, using iron in the form of a shell adjacent to the side surface of the reactor vessel and with the initial loading of acetic acid, acetic anhydride and iron oxide in a mass ratio of 100: (2 ÷ 5.99) :( 2 ÷ 2.5), with the selection of the solid phase of the reaction mixture by filtering, carried out at the time of almost complete consumption of iron oxide, with the return of the filtrate at the same time as feeding spent on the formation of the product of acetic acid and iron oxide and compensating for the loss of components of the liquid phase when filtering into the reactor for the second process. The second stage consists in the oxidation of the iron (II) salts separated in the precipitate during filtration into basic iron (III) acetate with oxygen during drying of the selected solid phase on the filter due to air flow at ambient temperature. Thus as the oxide Fe ₂ O ₃ is used, hematite, γ-oxide or red iron oxide, as Fe ₂ O ₄ - magnetite and Fe ₃ O ₄ · 4H ₂ O, and the second process is carried out at least 5 times in a row either with some interruptions .

Characteristics of the raw materials used

reactive iron according to TU 6-09-2227-81

iron carbonyl radio engineering grade R-20 according to GOST 13610-79

Iron oxides:

hematite according to GOST 4173-77

red lead according to TU 113-00-38-160-96

γ-oxide according to GOST 3540-82

magnetite in accordance with GOST 26475-85

crystalline iodine according to GOST 4159-79

acetic acid according to GOST 61-75

acetic anhydride according to GOST 5815-77

The process of the claimed method is as follows. The bead mill is equipped with an iron shell, glass beads, a loading of the liquid phase (a mixture of glacial acetic acid and acetic anhydride), as well as iodine, in a bead mill equipped with a reflux condenser and heating using a liquid bath moving along the longitudinal axis and iron oxide Fe ₂ O ₃ or Fe ₂ O ₄ . Mechanical stirring and heating are turned on using a preheated liquid bath and the temperature is brought to the set mode. Stirring is continued at a stabilized operating temperature, controlling the accumulation of iron salts in the reaction mixture by sampling. Upon reaching the almost complete consumption of the total loaded iron oxide, the resulting reaction mixture is sent to the filtering mode for cooling, having previously separated it from the beads, passing through a filter with a mesh of appropriate sizes. The filtrate obtained in this case is immediately returned to the repeated process, supplementing it with additional loading of acetic acid and iron oxide spent on the formation of the product, as well as compensation for the loss of components of the liquid phase during filtration (statistical variant on the principle of mass return to the value of the initial load). Next, a second process is carried out in accordance with the above sequence of operations.

The solid phase separated on the filter, which is a mixture of iron (III) and iron (II) salts, is dried in an air stream. During this operation, the iron (II) salt is oxidized to the main iron (III) acetate, which is the target product of this process.

The repeated process according to the described scheme is carried out several times (at least not less than 5), either directly one after another, or with some interruptions. During the latter, the bead mill should be filled with the charge and its free exit to the atmosphere through the reflux condenser should be interrupted.

Example No. 1.

In a vertical type bead mill with a glass casing with an inner diameter of 63.7 mm and a height of 109 mm and an iron shell inserted into it with a height of 70 mm and a weight of 84.13 g, which is sealed to a lid mounted on an iron frame with a stuffing box and seals for a mechanical mixer paddle type with a shaft and blades of textolite, as well as with a reflux condenser with free access to the atmosphere and a loading door, 115.4 g of glass beads and a loading of the reaction mixture, consisting of 110.44 g of l, are introduced edible acetic acid, 3.76 g of acetic anhydride, 1.17 g of molecular iodine and 7.35 g of reactive-purity γ-oxide Fe ₂ O ₃ . Mechanical stirring is turned on, a liquid bath preheated to 85 ° C is brought in from below so that the entire height of the reactor working zone is immersed in a heating liquid, cooling water is supplied to the reflux condenser, and the temperature is removed at 80 ° C for 15 minutes. They stabilize the temperature and in this mode carry out the process. In its course, without stopping mixing, samples of the reaction mixture are taken in which the content of iron (II) and iron (III) salts is determined, as well as the residual amount of iron oxide. As soon as the latter reaches a zero value (in this case, after 108 minutes), the stirring is stopped and the reaction mixture is sent to a filter through a connected bead screen. The separated filtrate in an amount of 94.71 g is returned to the bead mill for a second process. 19.31 g of acetic acid, 1.25 g of acetic anhydride, 0.23 g of iodine and 7.47 g of γ-Fe ₂ O ₃ are added to it, they include mechanical stirring, heating is supplied, the temperature is set for 80 minutes for 11 minutes ° C and carry out a repeated process as described above for 106 minutes

In parallel with the repeated process, the iron (II) salts are oxidized to the main iron (III) acetate on the filter, providing air flow through the layer of filtered precipitate at room temperature. It took 60 minutes. Simultaneously with the reoxidation of the iron (II) salt during this operation, the precipitate is dried from the components of the liquid reaction mixture (mainly acetic acid and to a lesser extent acetic anhydride) captured during filtration.

At the end of the first repeated process, the reaction mixture is separated from the beads, then filtered, the filtrate is sent to the second repeated process, and the filter cake is treated with an air flow for 55 minutes to further oxidize the iron (II) salt to basic iron (III) acetate.

A total of repeated processes is carried out 5. Raw materials are loaded and their characteristics are given in Table 1.

Table 1

Liquid component reloading
phase and iron oxide; time characteristics Repeat process second third fourth fifth Acetic acid, g 19.05 19.84 20.11 22.13 Acetic anhydride, g 0.87 1.15 1.43 1,53 Iodine, g 0.04 0.11 0.13 0.08 Iron oxide, g 7.42 7.28 7.37 7.34 The duration of reaching a temperature of 80 ° C, min twenty fourteen 17 12 The duration of the process, min 104 114 120 128 Duration of oxidation of iron (II) salt on the filter, min fifty 65 65 70

In the initial and five subsequent repeated processes, 151.2 g of dried basic acetate (III) were obtained. In this case, the filtrate remained in the amount of 89.2 g, which could well be returned to the process after appropriate feeding with acetic acid, acetic anhydride and iodine and the introduction of the next portion of γ-oxide.

Examples 2-9.

The reaction apparatus, the sequence of operations for loading, bringing the temperature to a predetermined mode and stabilizing it, carrying out the process, separating the reaction mixture from the beads and the solid phase from it, oxidizing the iron (II) salts in the separated solid precipitate on the filter, returning the filtrate to a second process, reloading the components of the liquid phase, taking into account compensation for losses during filtration, introducing a new portion of iron oxide and carrying out the first and subsequent repeated processes, the number of repeated processes is similar to those described in example 1. are characterized by the nature of iron oxide, the initial molar ratio of acetic acid, acetic anhydride and iron oxide, the presence of a break in the subsequent re-process and other time characteristics. The results obtained are summarized in table 2.

The positive effect of the proposed solution is as follows:

1. The method is implemented at relatively low temperatures, in the absence of pressure, simple in hardware design, has many simple solutions to maintain a given temperature regime.

2. There are no energy-intensive stages such as evaporation of a solution. The filtrates can be used repeatedly for their intended purpose or to compensate for the loss of the liquid phase during filtration.

3. From 2/3 to 3/4 of the salt formed is obtained from iron oxide, which can be used available natural minerals.

Claims (3)

1. The method of producing basic iron (III) acetate by the interaction of metallic iron with acetic acid in the presence of an oxidizing agent, characterized in that at the first stage, iron oxide Fe ₂ O ₃ or Fe ₃ O ₄ and molecular iodine in an initial molar ratio of 10 are taken : 1, and the process itself is carried out at 80 ° C in a vertical type bead mill with glass beads as an oxide grinding agent in a mass ratio with a 1: 1 liquid loading phase, with a high-speed mechanical stirrer and with a reflux condenser in the absence of air flow through the gas space of the reactor, but without particular restrictions on the isolation of this space of the reactor from the atmosphere, using iron in the form of a shell adjacent to the side surface of the reactor vessel, and with the initial loading of acetic acid, acetic anhydride and iron oxide in a molar ratio 100: (2-5.99) :( 2-2.5), with the selection of the solid phase of the reaction mixture by filtration, carried out at the time of almost complete consumption of iron oxide, with the return of the filtrate simultaneously with the replenishment of the expenditure data on the formation of the product of acetic acid and iron oxide and compensation for the loss of components of the liquid phase when filtering into the reactor for the second process and the oxidation of residues of the iron (II) salt in the second stage into basic iron (III) acetate during drying of the selected solid phase of the product on the filter by air flow at ambient temperature. 2. The method according to claim 1, characterized in that hematite, γ-oxide or minium are taken as iron oxide Fe ₂ O ₃ , and magnetite and Fe ₃ O ₄ · 4H ₂ O are taken as Fe ₃ O ₄ . 3. The method according to claim 1, characterized in that the repeated process is carried out at least 5 times in a row or with some interruptions.