Basic ferric acetate preparation method

FIELD: industrial inorganic synthesis.

SUBSTANCE: implementation of the method comprises contacting iron in the form of iron powder or iron sidewall adjacent to a body with glacial acetic acid and air oxygen at 17-25°C and vigorous stirring effected by high-speed blade-type mechanical stirrer. Initial acetic acid-to-iron molar ratio is (224÷274):100. Acetic anhydride additive is preferably introduced in amount of 2% based on the initial concentration of acetic acid. When concentration of ferric salt in the mixture reaches 2.70-3.51 mole/kg, stirring is stopped and heavy unreacted iron particles are allowed to settle/ Major mass of product suspension is filtered off and thus obtained basic ferric acetate precipitate is dried. Filtrate, which is saturated acetic acid solution of basic ferric acetate, is returned into reactor to be reprocessed. Yield of desired product achieves 99.2-99.3%.

EFFECT: simplified process and improved economical efficiency due to utilization of inexpensive raw material and accessible oxidant.

2 ex

The invention relates to a technology for obtaining a basic salt of trivalent iron and acetic acid and can be used in various fields of industrial and laboratory chemicals and analytical methods of control.

It is known that the interaction of iron in acetic acid with molecular iodine without limitation of the access of air to the reaction mixture leads to the formation as one of the main components of acetate of iron (III) (Amiano, Sportwhat, Sviridonova. Some ways of spending of iron in solutions of iodine in low molecular weight fatty acids and evaluation of their competitive ability // proceedings of the Kursk state technical. Univ. Kursk, 2003, №1 (10). P.59-63).

The disadvantage of this option is that the basic acetate of iron (III) is the product of the oxidation of iodide iron (II), accompanied by replacement of the anion J^-on acetate in the course of such interaction. The final basic acetate of iron (III) will be contaminated by products containing J^-anions in poorly controlled quantity.

Closest to the claimed method is to obtain the formate or acetate India (A.S. USSR №454198), according to which the original acid is subjected to interaction with the metal indium in the presence of hydrogen peroxide, followed by extraction of the target product are known for the mi techniques.

The disadvantages of this method are:

1. It does not cover the use as a reductant instead of India iron, although the admixture of compounds of the latter in the final product is marked in the amount of 10^-3%.

2. The possibility of using iron in this process difficult as salts of iron (III) is known as highly efficient catalysts for the decomposition of hydrogen peroxide with the formation of molecular oxygen. Accumulate as the main product, a salt of iron (III) can determine whether the specified decomposition of hydrogen peroxide as the dominant, and the oxidation of the metal will become uncompetitive option.

3. Hydrogen peroxide is not a natural connection requires a special receipt and in this respect inferior to natural oxidants.

4. In the cited process uses temperature 80-100°C. Such temperatures, though small, but determine significant consumption of the process.

The objective of the proposed solutions is to use leading to the formation of basic acetate of iron (III) redox process iron as a reductant and oxygen as the oxidant, and the process is carried out with positive ambient temperatures.

This object is achieved in that the reaction take poroshkoobraznoe iron individually or together with adjacent to the reactor vessel metal shell, and as oxidant use the oxygen of the atmospheric air supplied to the mode effective bubbling, and the process is carried out at a temperature of 17-25°in the environment of glacial acetic acid, taken in a molar ratio with powdered iron (224÷274):100, with high-speed stirring with a mechanical stirrer vane type in the absence or in the presence of additive acetic anhydride in the amount of 2.0 wt.% downloaded from acetic acid to accumulate in the system of suspension of the product with the content of the basic acetate of iron (III) 2,70-3,51 mol/kg, followed by the termination of stirring, separating the slurry from settling on the bottom of the heavy particles of unreacted iron, filtering basic acetate of iron (III) and returning the filtrate to the reactor to boot to re-process.

Characteristics of the raw materials used

Iron recovered in THE 6-09-2227-81

Iron Steel 3 on CMTU 1-84-67

Acetic acid according to GOST 61-75

Acetic anhydride according to GOST 5815-77

The process of the inventive method the following. In made of iron, stainless steel or glass reactor vessel with a mechanical stirrer with blades of stainless steel or inert plastic (Teflon) is inserted adjacent to the minimum clearance to the body shell of iron (but you can do without it). To the STS combined with the cover and through the loading hatch enter the estimated amount of iron powder, glacial acetic acid and, if applicable, acetic anhydride. Include mechanical mixing and serves duct air with controlled flow sparging. The process begins when 17-25°and lead naturally when the current temperature is mainly due to heat when mixing heavy particles of iron powder. Typically, the temperature rise does not exceed 10-15°C. during the process, select the first sample solution, and then the suspension of iron salts, which determine the content of iron (III). As soon as the latter reaches the set value, the stirring stopped, give time to settle the heavy particles of iron, but much worse than settling suspension of iron salts are selected for filtering. Solid salt is dried, and the filtrate is returned to the reactor for re-download process.

Example 1.

In a reactor made of stainless steel (inner diameter of 80 mm and a height of 200 mm with a spherical bottom and a drain pipe located at a height of 10 mm from the bottom point), equipped with a paddle agitator with bottom profile of the blade, repeating spherical bottom and separated from it by 0.3-0.6 mm, and cover with stuffing box for stirrer, reflux-condenser and pipes for the bubbler and sampling during the process, introduced 200 g of the powder recovered iron with a maximum linear R is Merom particles of 0.6 mm, 480 g of acetic acid and 9.6 g of acetic anhydride. Include mechanical stirring (1440 rpm) and served in the air with a flow rate of 0.97 l/min Initial temperature of 17°C. during the process without stopping stirring take samples of the reaction mixture, which determine the total amount of salts of iron (II) and (III) separately and salts of iron (III), which generally coincide well with each other. After 3 hours, 14 minutes the temperature in the reactor reached 28°and the amount of salt of iron (III) suspension 3,51 mol/kg

Stop mechanical stirring, allow 3 minutes for the deposition of particles of unreacted iron on the bottom of the reactor, and then through the side drain pipe suspension of the salt of the basic acetate of iron (III) on the filter where they spend the separation of the solid salt from its saturated solution. Solid salt is dried in air and then in a drying Cabinet. The output amounted to 436 g of dry product, 3.5 g of the product was in the reactor (not merged suspension and return with filtrate), which is determined by the salt concentration in the reaction mixture after re-loading of acetic acid with the addition of acetic anhydride to repeat the process. With this in mind, the output amounted to 99.2%. The rest is lost when the reaction mixture from the reactor site filtration and the filtrate back.

Example 2.

In the reactor with a glass case inside nim diameter of 63.7 mm and a height of 109 mm and inserted metal shell height 74,8 mm and weight 97,17 g enter 55,0 g of iron and 161.6 g of glacial acetic acid. The body is placed in the slot of the frame, combined with a lid, in which there is an inlet for reverse refrigerator-condenser, stuffing box for mechanical agitator shaft and blades of Teflon, flexible bubbler and the sampler. Include mechanical stirring (720 rpm), serves air sparging with a flow rate of 0.27 l/min and the time taken for the beginning of the process. The temperature at this time was 25°C. during the process, take samples of the reaction mixture, which analyze the content of salts of iron (III). Through 204 min it was equal 2,70 mol/kg, and the temperature rose to 31°C. Stop mechanical stirring for 4.5 min enable the heavy particles of unreacted iron to settle to the bottom, then gently poured a suspension of the product on the filter and carry out the separation of the solid phase from the liquid. The filtrate is returned to the reactor to repeat the process. And the residue dried on the filter, and then in a drying Cabinet. Received and 99.8 g of dry salt. Taking into account the returned product in the reactor to repeat the process output amounted to 99.3 percent.

The positive effect of the proposed solutions is the following:

1. The proposed method is simple in execution and hardware design, as well as from the point of view of selection of the target product. Taking into account the temperature holding it is quite possible from what the input to low.

2. In the absence of the stringent requirements for purity of the product as the source of iron may be used sawdust and soft shavings, i.e. waste Metalworking industries.

3. When disposing of accumulated after the separation of the target product of the liquid phase, representing a saturated solution of basic acetate of iron (III) in acetic acid or in a mixture of acetic acid and acetic anhydride, there is no need in her separation, the separation and purification of individual components. There are many options for the use of such liquid phase as an independent raw material.

4. The product can be easily recrystallized and in this way increase the purity of the obtained basic acetate of iron (III).

The method of obtaining basic acetate of iron (III) interaction of metal with acetic acid in the presence of an oxidizing agent, characterized in that the reaction take powdered reduced iron individually or together with adjacent to the reactor vessel metal shell, and as the oxidant used the oxygen of the atmospheric air supplied to the mode effective bubbling, and the process is carried out at a temperature of 17-25°in the environment of glacial acetic acid, taken in a molar ratio with powdered iron (224÷274):100, with high-speed stirring with a mechanical stirrer is dangerous types in the absence of or in the presence of additive acetic anhydride in the amount of 2 wt.% downloaded from acetic acid to accumulate in the system of suspension of the product with the content of the basic acetate of iron (III) in an amount 2,70-3,51 mol/kg, followed by the termination of stirring, separating the slurry from settling on the bottom of the heavy particles of unreacted iron, filtering basic acetate of iron (III) and returning the filtrate to the reactor to boot to re-process.