Method of producing magnetite with developed surface

FIELD: chemistry.

SUBSTANCE: invention can be used in chemical industry. The method of producing magnetite with a developed surface involves preparation of iron (II) chloride and iron (III) nitrate solutions and draining the solutions of the obtained salts. Carbonyl iron is used to obtain the iron salts. Iron (III) nitrate is obtained by adding 50-60 ml of 3% hydrogen peroxide solution. A protective toluene film forms over the iron (II) chloride solution. The mixture of iron (II) chloride and iron (III) nitrate solutions is then precipitated with a solution which is prepared by pouring 1 litre of 25% ammonia solution to 8 litres of distilled water while stirring intensely.

EFFECT: invention increases specific surface area of magnetite to 130 m2/g.

1 ex

 

The invention relates to the field of chemical industry, and in particular to methods for producing metal oxides.

A known method of producing magnetite "inorganic synthesis Manual" (edited by Gbauer, M., 1985, volume 5, s), including:

the heating of fine powder of Fe2O3in a boat in a stream of nitrogen at 400°C;

- replacement of nitrogen to hydrogen, saturated at 50°With water vapor until remediation is complete when no visible traces of red Fe2O3, (about 5 hours) at the same temperature (400°C), - cooling in a stream of nitrogen.

The disadvantage of this method is the low specific surface area of the obtained magnetite (45 m2/g), which was determined by volumetric method at constant pressure [1, 2].

Closest to the proposed are methods of obtaining magnetite Fe3O4merge solutions of salts of Fe2+and Fe3+:

a) known from the application CN 101382689 (.C01G 49/02, 11.03.2009)

b) (Uphyrkina, Geo. Pure chemical substance, 1974, p.100), including:

the dissolution rates of crystalline iron sulfate (II) (FeSO4·7H2O) -, and (III) - Fe(SO4)3·9H2O - 0,044 mol in 500 ml of water;

the injection of this solution into 1 l of boiling 5% solution of KOH;

- quick washing the precipitate with hot water by decantation;

- suction and extraction of the precipitate with a Buechner funnel;

- su is ka precipitate in an atmosphere of hydrogen over calcined CaCl 2or over conc. H2SO4

The disadvantage of these methods is the low specific surface area of the obtained magnetite.

The purpose of the invention is to increase the specific surface of magnetite.

The method of producing magnetite Fe3O4with a developed surface includes:

- getting solution of salt of Fe2+- dissolution of the sample Cabanillas iron conc. hydrochloric acid;

- creation of the above solution of the protective film from toluene to prevent air oxidation;

- getting solution of salt of Fe3+- dissolution of the sample carbonyl iron 15%HNO3;

- introduction to the obtained solution of salt of Fe3+50-60 ml of 3%solution of H2O2for a complete oxidation;

- heating of the reaction mixture to a negative reaction on Fe2+with [Fe(CN)3]2+;

- evaporation of salt nitrate Fe3+;

- preparation of a mixture precipitator: a 10 litre capacity pour 8 liters of distilled water and pour into it 1 l of a 25%solution of NH4OH;

- merging cooled to room temperature salt solutions of FeCl2and Fe(NO3)3and bring the solution volume to 1 liter;

slow infusion of a mixture of solutions of salts in the precipitant solution under vigorous stirring;

- maintaining the suspension of magnetite in the mother solution until precipitation of magnetite with placed under the container is determined as being a magnet;

- removal of the supernatant liquid and repeated washing of magnetite with distilled water until a negative reaction to the ions Cl-;

- replacement of water in alcohol, filtering the precipitate of magnetite with a Buechner funnel and drying it at room temperature.

A new method of producing magnetite is that:

a) the starting material for obtaining salts FeCl2and Fe(NO3)3is carbonyl iron;

b) iron nitrate Fe(NO3)3obtained by adding a solution of H2O2for a complete oxidation;

C) magnetite obtained by precipitation in aqueous ammonia mixture salt solutions of FeCl2and Fe(NO3)3.

Specific example: the molar ratio of FeCl2to Fe(NO3)3should be 1:2.

Preparation of a solution of iron chloride (II): 12 g carbonyl iron dissolved in conc. HCl (in fume hood), for protection from oxidation above solution to form a protective film of toluene.

Preparation of a solution of iron nitrate (III): 24 g carbonyl iron dissolved in 15%nitric acid (in the hood) with gentle heating. For a complete oxidation of iron to enter in a solution of 50 ml of 3%solution of H2O2with constant stirring. Boil the solution until complete dissolution of iron and to a negative reaction on Fe2+.

P is the production of precipitant solution in a 10 gallon tank pour 8 liters of fresh distilled water, then pour it with 1 l of 25%ammonia solution.

Preparation of magnetite Fe3O4: solutions of salts of iron chloride (II) FeCl2and nitrate iron (III) Fe(NO3)3cooling to room temperature, pour together, the resulting mixture was brought to 1 l with distilled water and slowly pour in the precipitant solution under vigorous stirring. Received a suspension of magnetite to withstand over a powerful magnet, which is placed under the container with a solution. After deposition of magnetite to drain off the supernatant liquid and the method of decantation wash the solids with new portions of water until a negative reaction to chloride ions. Replace the water in the ethanol, filter the precipitate of magnetite with a Buechner funnel and air dried at room temperature. Determination of specific surface area, carried out by volumetric method at constant pressure [1, 2] showed that S.=130 m2/year

Literature

1. Greg S., Singh K. Adsorption, specific surface area and porosity. - M.: Mir, 1984.

2. Meemken. GFH, 29, 9, 1610, 1955.

The method of producing magnetite with a developed surface, including the production of solutions of salts of iron chloride (II) and iron nitrate (III), draining fluids received salts, characterized in that for obtaining iron salts using carbonyl iron, and nitrate iron (III) are produced by adding 50-60 ml of 3%Rast is ora hydrogen peroxide, and over the salt solution of iron chloride (II) create a protective film of toluene, the mixture is then solutions of salts of iron chloride (II) and iron nitrate (III) is precipitated by a solution prepared by infusion of 1 l of 25%ammonia solution in 8 l of distilled water under vigorous stirring.



 

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