RU2292331C1 - Method of production of the ferric formiate (ii) - Google Patents

Abstract

FIELD: chemical industry; methods of production of the salts of iron and the organic acids.

SUBSTANCE: the invention is pertaining to the field of chemical industry, in particular, to the method of production of the salts of iron and the organic acids, in particular, to production of the salt of the ferrous iron and the formic acid. The method is realized by the direct interaction of the acid with the iron, its alloys and the ferric oxides. The crumber with the beads and the backflow condenser is loaded with the organic solvent, the formic acid and the water in the mass ratio of 100:(85÷100): (15÷0). As the organic solvent they use ethylcellosolve, butyl acetate, butyl and amyl alcohols, ethylene glycol. The mass ratio of the beads and the liquid phase is 1:1. Ferric oxide Fe₂O₃ or Fe₃O₄ and the iodine are loaded in the amount of 0.40-0.56 or 0/21-0.42 and 0.03-0.1 mole/kg of the liquid phase accordingly. The iron is introduced in the form of the steel shell along the whole height of the reactor and additionally in form of the reduced iron, the fractions of the broken cast iron with dimensions of up to 5 mm and the steel chips in any ratio among themselves at total amount of 20 % from the mass of the liquid phase. The process is conducted at the temperature of 35-55°C practically till the complete consumption of the ferric oxide. The gained suspension is separated from the beads and the metal particles of the greater dimensions and subjected to centrifuging or sedimentation. The clarified liquid phase is returned to the repeated process, and the solid phase is dissolved at stirring action and warming up to 85-95°C in the water solution of the formic acid saturated by the ferric formiate (II) up to 1-2 mole/kg. The present solid impurities are removed at the hot filtration process and the filtrate is cooled and the salt crystals are separated. The technical result of the invention is simplification of the technology of the production process with utilization of the accessible raw.

EFFECT: the invention ensures simplification of the technology of the production process with utilization of the accessible raw.

3 cl, 17 ex

Description

The invention relates to a technology for the production of ferrous salt and formic acid and can be used in various fields of industrial and laboratory chemistry, in the preparation of composite materials and in analytical control.

It is known that the interaction of iron with formic acid in the presence of molecular iodine without limiting the contact of the reaction mixture with air leads to the accumulation of iron (II) formate in amounts significantly exceeding the stoichiometric values for charged iodine (A.M. Ivanov, S.P. Altukhov, SV Filimonova, Some Ways of Consuming Iron in Iodine Solutions in Low Molecular Fatty Acids and Assessing Their Competitiveness // Bulletin of the Kursk State Technical University, Kursk 2003, No. 1 (10), pp. 59-63).

The disadvantages of this option are;

1. The use of a liquid medium is only formic acid, which is quite volatile, which significantly limits the upper limit of the temperature regime of the process and requires highly efficient operation of the condenser and the acid recovery system as a whole.

2. The main raw material for product cations is iron, which, unlike iron oxides, Fe ₂ O ₃ or Fe ₃ O ₄ is not a natural compound.

3. From too concentrated solutions of formic acid, the allocation of salt is very difficult.

Closest to the claimed is a method for producing iron (II) acetate according to the patent of the Russian Federation 2259994, publ. September 10, 2005, according to which iron and iron oxide Fe ₂ O ₃ or Fe ₃ O ₄ are introduced into interaction with acetic acid in the presence of iodine as an oxidizing agent of iron and acetic anhydride as a water-taking agent and a stimulating additive at 80 ° C in nitrogen with periodic selection of the solid phase of iron (II) acetate in order to avoid excessive thickening of the suspension and turning the reaction mixture into a paste.

The disadvantages of this method are:

1. A rather high temperature of the process (80 ° C). Compared with acetic acid, formic acid boils at a lower temperature, and therefore more volatile. Therefore, with a gas flow, its entrainment is much larger, which requires an increase in the efficiency of the used reverse condenser refrigerator and additional technological solutions. Therefore, the use of formic acid as the basic component of the liquid phase of the reaction mixture under such temperature and other conditions is hardly possible.

2. Carrying out the process in a nitrogen medium (duct) leads to increased ablation of acid and creates significant difficulties not only in the process itself, but also in the isolation of the product, i.e. in the processing of the reaction mixture.

3. The model of this process can hardly be fully implemented for formic acid, since formic acid anhydride simply does not exist, and therefore, there is no fundamental possibility to reproduce the formulation used in the prototype.

The objective of the proposed solution is to obtain iron (II) formate from iron and iron oxides Fe ₂ O ₃ or Fe ₃ O ₄ in their interaction with formic acid dissolved in organic media in the absence of dewatering agents, an inert gas medium and special heat supply to provide the necessary temperature mode.

The problem is achieved in that the loading on the process consists of a liquid phase, iron oxide Fe ₂ O ₃ or Fe ₃ O ₄ , iodine, metallic iron and (or) its alloys, while the liquid phase of the load, including an organic solvent, formic acid and water in a mass ratio of 100: (85 ÷ 100) :( 15 ÷ 0), taken in relation to the mass of beads 1: 1, iron oxide Fe ₂ O ₃ or Fe ₃ O _{4 is} dosed in an amount of 0.40-0.56 or 0.21-0.42 mol / kg of the liquid phase, iodine is loaded in an amount of 0.03-0.10 mol / kg of the liquid phase, iron is introduced in the form of a steel shell along the entire height of the side surface ctor and additionally in the form of a powder of reduced metal, pieces of broken cast iron and (or) steel chips with a maximum linear size of 5 mm in any ratio to each other in a total amount of 20% of the mass of the liquid phase of the system, and the process starts at ambient temperature and is carried out without any obstacles to contact with air, while limiting the temperature spontaneously rising due to exothermic stages in the range of 35-55 ° C until almost all of the loaded iron oxide is consumed, then mix The reactor is stopped and cooled, the suspension of the reaction mixture is separated from the beads and large metal particles when draining through a metal mesh in the drain pipe of a bead mill and centrifuged or sedimented, after which the clarified liquid phase is returned to the repeated process, and the precipitate is dissolved in saturated iron formate 1 -2 mol / kg of an aqueous solution of formic acid when heated to 85-95 ° C, solid impurities of finely divided iron, residues of unreacted iron oxide, carbon from cast iron and steel removed by hot filtration, the filtrate was left for natural cooling and crystallization of iron formate (II). In this case, ethyl cellosolve, butyl acetate, butyl alcohol, amyl alcohol, ethylene glycol are used as an organic solvent. Especially, no water is introduced into the initial loading, but only with dosed formic acid.

Characteristics of the raw materials used.

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

Steel 3 according to ChMTU 1-84-67

Steel 45 according to GOST 1050-74

Gray cast iron SCH 15-32 according to GOST 1412-70

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

Formic acid according to GOST 5848-73

Crystalline iodine according to GOST 4159-79

Ethyl cellosolve according to GOST 8313-88

Butyl acetate according to TU 22P-12-68

Butyl alcohol according to GOST 6006-78

Amyl alcohol according to GOST 5830-77

Ethylene glycol according to GOST 10164-75

The process of the claimed method is as follows. Glass beads and a liquid loading phase are introduced into a vertical type bead mill equipped with a high-speed paddle mixer, a reflux condenser, a drain pipe with a mesh with mesh sizes of 0.5 × 0.5 mm, a steel shell over the entire height of the casing and a forced cooling system as well as additionally iron oxide, crystalline iodine, reduced iron powder, and / or beaten cast iron, and / or broken steel chips in pieces in appropriate quantities. The bead mill is placed at the workplace, the necessary communications and the forced cooling system are connected, mechanical stirring is turned on, and this moment is taken as the beginning of the process. Observe the temperature change of the reaction mixture. At first, it does not change much, then it begins to accelerate automatically. Forced cooling is turned on and the temperature is stabilized in the range of 35-55 ° C.

Upon reaching almost complete consumption of iron oxide, the stirring is stopped, the reaction mixture is separated from the beads and large pieces of unreacted cast iron and shavings when draining through the lower pipe with a mesh and sent for centrifugation or settling. The clarified liquid phase is returned to the repeated process, and the precipitate is dissolved by heating in saturated with formate of iron (II) 1-2 mol / kg aqueous solution of formic acid with stirring. Upon completion of the dissolution process, the resulting mass is filtered, solid impurities are removed, and the filtrate is left to slowly cool and crystallize iron (II) formate. Upon completion of crystallization, the solid product is separated and dried, and the filtrate is sent to prepare a 1-2 mol / kg formic acid solution saturated with iron (II) formate.

Example 1

In a vertical type bead mill with a stainless steel casing (internal diameter 80 mm and height 200 mm with a spherical bottom and a drain pipe located at a height of 10 mm from the lower point), equipped with a paddle mixer with a lower profile of the blade, repeating the spherical bottom and separated from 0.3-0.6 mm, and a lid with a stuffing box for the mixer, a condenser reflux condenser, a loading door, a thermocouple pocket and a sampling pipe during the process, as well as filled dead zones of the apparatus ktsionnoy mixture previous process is introduced 450 g beads and 450 g of liquid phase, which is a formic acid solution of iodine in ethyl cellosolve and with concentrations of 9.24 mol / Kg and 0.1 mol / kg, respectively. To prepare such a solution, 85% formic acid was used, taken in a ratio by weight with a solvent of 1: 1. Thus, the initial mass ratio of solvent: acid: water is 100: 85: 15. After that, 90 g of reduced iron and 43.8 g of iron oxide Fe ₃ O ₄ are charged. include mechanical stirring (1440 rpm, power 0.5 kW). The initial temperature is 20 ° C. Observe the temperature change along the way. After 15 minutes, it became 30 ° C. Cool with a liquid bath and keep the temperature at 36 ± 1 ° C. At the same time, without stopping mixing, samples of the reaction mixture are taken, in which the total content of iron (II) salts is determined, as well as the residual amount of iron oxide at the moment. As soon as the latter becomes close to zero, and this happened 80 minutes after the start, the mechanical stirring is stopped, several minutes are allowed to precipitate heavy iron particles, and the reaction mixture is separated from the beads through a drain pipe mesh with a mesh size of 0.5 × 0.5 mm . Thus, 505 g of the reaction mixture, which is a rather viscous, but still mobile suspension, is slightly pink in color. The content of iron salts in it according to the analysis of 1.5 mol / kg

The resulting suspension is sent for centrifugation, the clarified layer is selected, weighed, the content of the iron (II) salt in it is determined and returned to the repeated process. The remaining compacted precipitate is transferred to a heat-resistant container with a paddle mechanical stirrer, into which 750 g of a solution of formic acid saturated with formate of iron (II) with a concentration of 1.12 mol / kg are introduced. Mechanical stirring and heating are included. Dissolve the deposited precipitate for 83 minutes. Upon reaching almost complete dissolution of the entire precipitate, heating is stopped. The temperature at this moment was 91 ° C. The solution with solid phase impurities is quickly transferred to a filter heated to approximately this temperature and separation of undissolved impurities is carried out. The mass of the latter amounted to 0.38 g. These are mainly fine particles of unreacted oxide.

The filtrate was allowed to cool naturally and crystallize iron (II) formate. After 12 hours, the precipitated iron (II) formate is filtered and dried. Received 116.5 g of dry salt. After determining the content of the salt of iron and formic acid in it, the filtrate is used to prepare a solution for subsequent recrystallization.

Examples 2-10

The bead mill used, the amount of beads in it, the solvent, iron oxide, the loading of the liquid phase, and the process flow and product isolation are similar to those described in Example 1. They differ in the concentrations of formic acid and iodine in the initial liquid phase, using beaten iron, broken steel chips and mixtures thereof with each other and with reduced iron, as well as the amount of Fe ₃ O ₄ in the load. The results obtained are summarized in the table. (Designations: PC - reaction mixture, LF - liquid loading phase; DF - centrifugation, O - sedimentation)

Example 11-17

The bead mill used, the amount of bead and liquid phase loading in it, the sequence of operations of the process for producing and isolating iron (II) formate are similar to those described in Example 1. They differ in the nature and amount of iron oxide, as well as the nature of the solvent. The results obtained are summarized in the table. (Designations: EC - ethyl cellosolve, EG - ethylene glycol, BA - butyl acetate, BS - butyl alcohol, AC - amyl alcohol).

The positive effect of the proposed solution is:

1. This process does not require the supply of external heat, it is simple in hardware design, easy to control and safe to perform when loading, where heating the reaction mixture with the cooling system used does not lead to its boiling and too boiling.

2. In this process, the bulk of the salt is formed from metal oxides, the almost complete consumption of which clearly determines the time the process ends.

3. This process uses available raw materials, optionally of reactive purity, and the resulting product is easily isolated from the reaction mixture and can be sufficiently purified by recrystallization.

Claims (3)

1. A method of producing iron (II) formate by direct interaction of an acid with iron, its alloys and oxides Fe ₂ O ₃ and Fe ₃ O ₄ in the presence of stimulating additives of iodine in a bead mill with a reflux condenser, a high-speed paddle mixer and glass beads in as a grinding agent, characterized in that the loading on the process consists of a liquid phase, iron oxide Fe ₂ O ₃ or Fe ₃ O ₄ , iodine, metallic iron and (or) its alloys, while the liquid phase of the load, including an organic solvent, formic ki lot and water in a weight ratio of 100: (85-100) :( 15-0), taken in relation with the mass of beads 1: 1, the iron oxide Fe ₂ O ₃ or Fe ₃ O ₄ is dosed in an amount of 0,40-0, 56 or 0.21-0.42 mol / kg of the liquid phase, iodine is loaded in an amount of 0.03-0.10 mol / kg of the liquid phase, iron is introduced in the form of a steel shell along the entire height of the side surface of the reactor and additionally in the form of reconstituted powder iron, pieces of broken cast iron and (or) steel chips with a maximum linear size of 5 mm in any ratio to each other in a total amount of 20% of the mass of the liquid phase of the system, and the process itself start at ambient temperature and are carried out without any obstacles to contact with air while restraining the temperature that spontaneously rises due to exothermic stages by forced cooling in the range of 35-55 ° C until almost all of the loaded iron oxide is consumed, after which the stirring and cooling are stopped, the suspension the reaction mixture is separated from the beads and large metal particles by passing through a metal mesh in the discharge nozzle of a bead mill and subjected to centrifugation and sedimentation, after which the clarified liquid phase is returned to the repeated process, and the precipitate is dissolved in a saturated formate of iron (II) 1-2 mol / kg aqueous solution of formic acid when heated to 85-95 ° C, solid impurities of finely divided iron, residues of unreacted oxide iron and carbon from iron and steel are separated by hot filtration, the filtrate is left to naturally cool and crystallize iron (II) formate. 2. The method according to claim 1, characterized in that ethylcellosolve, butyl acetate, butyl alcohol, amyl alcohol, ethylene glycol are used as the organic solvent. 3. The method according to claim 1, characterized in that water is not specifically introduced into the initial charge, but only with dosed formic acid.