Obtaining

• · Minerals meet in nature Braunit, Kurnakit and Buxbiite - manganese oxide with various impurities.
• · Oxidation of manganese oxide (II):
• · Manganese oxide recovery (IV):

Physical properties

Manganese oxide (III) forms brown-black crystals of several modifications:

• · B-MN2O3, Rhombic Singonia, Mineral Kurnakit;
• · B-Mn2O3, cubic single, spatial group I A3, cell parameters a \u003d 0.941 nm, z \u003d 16, mineralbixbite;
• · Mr. MN2O3, Tetragonal Singonia, cell parameters a \u003d 0.57 nm, C \u003d 0.94 nm.

Not dissolved in water.

Paramagnetic.

Chemical properties

Decomposes when heated:

• · Restored by hydrogen:
• · When dissolved in acids - disproportionates:
• · When fusing with metal oxides, monganitis salts are formed:

Manganese oxide (IV)

Table 6. Manganese oxide (IV).

Chemical properties

Under normal conditions, it behaves quite inert. When heated with acids, oxidative properties exhibit, for example, oxidizes concentrated hydrochloric acid to chlorine:

With sulfur and nitric acids MnO2 decomposes with oxygen release:

When interacting with strong oxidizers, manganese dioxide is oxidized to Mn7 + and Mn6 + compounds:

Manganese dioxide manifests amphoteric properties. Thus, during the oxidation of the sulfate solution of salt MNSO4 permanganate potassium in the presence of sulfuric acid, a black sediment of Mn (SO4) 2 salts is formed.

When fusing with alkalis and the main oxides, MnO2 acts as acid oxide, forming a carcanita salt:

It is a catalyst for decomposition of hydrogen peroxide:

Obtaining

In the laboratory conditions are obtained by thermal decomposition Permanganate Potassia:

Also possible to obtain potassium permanganate reaction with hydrogen peroxide. In practice, the formed mno2catalogically decomposes hydrogen peroxide, as a result of which the reaction does not pass to the end.

At temperatures above 100 ° C restoration of potassium permanganate hydrogen:

Manganese oxide (VII)

• · Manganese oxide (VII) Mn2O7 - greenish-brown oil liquid (TPL \u003d 5.9 ° C), unstable at room temperature; Strong oxidizing agent, when contacting with combustible substances ignites them, possibly with an explosion. Explodes from shock, from a bright flash of light, when interacting with organic substances. To obtain manganese oxide (VII) Mn2O7 can be actions of concentrated sulfuric acid per potassium permanganate:
• · The resulting manganese oxide (VII) is unstable and decomposed on manganese oxide (IV) and oxygen:
• · At the same time ozone stands out:
• · Manganese oxide (VII) interacts with water, forming manganese acid:

Manganese oxide (VI)

Table 7. Manganese oxide (VI).

Manganese oxide (VI) - inorganic connection, manganese metal oxide with MnO3 formula, dark red amorphous substance reacts with water.

dioxide Manganese Obtaining chemical

Obtaining

· It is formed during the condensation of purple vapors allocated when the solution is heated Permanganate potassium in foreign acid:

Physical properties

Manganese oxide (VI) forms a dark-red amorphous substance.

Chemical properties

• · Decomposes when heated:
• · Reacts with water:
• · With alkalis forms salts - manganats:

Patterns change in the properties of manganese oxides

MnO2, Mn2O3 and Mn3O4 are most stable (mixed oxide - trimmarganic tetraoxide).

The properties of manganese oxides depend on the degree of metal oxidation: with an increase in the degree of oxidation, acidic properties are enhanced:

MNO\u003e Mn2O3\u003e MnO2\u003e Mn2O7

Manganese oxides exhibit oxidative or reducing properties depending on the degree of metal oxidation: higher oxides - oxidizers and restored to MnO2, lower oxides - reducing agents, oxidizing, form MNO2. Thus, the MNO2 is the most steady oxide.

methods for obtaining manganese dioxide

The invention relates to the field of metallurgy, more specifically, to obtain high-quality manganese oxides, which can be widespread in the chemical and metallurgical industries. The method of obtaining manganese dioxide includes the dissolution of manganese-containing raw materials in nitric acid to obtain a solution of manganese nitrates and nitrates present in the ore of calcium, potassium, magnesium, sodium. Then the thermal decomposition of nitrates in the autoclave is carried out. The thermal decomposition is carried out with a constant reduction in the pressure in the autoclave, ranging from the pressure of 0.6 MPa and reducing it to the end of the process to 0.15 MPa. In this case, the thermal decomposition with a thermal decomposition is continuously stirred by a stirrer rotating at a speed of 1-15 rpm and with the imposition of vibration with a frequency of 20-50 hertz. The method can be implemented at the enterprises of the chemical profile, which have in its composition autoclaves operating under pressure. The technical result of the invention is to obtain high-quality manganese dioxide. 2 Tab., 2 pr.

The invention relates to the field of ferrous metallurgy, more specifically, to obtain high-quality manganese dioxide, which can be widespread in the chemical and metallurgical industry, in particular in the production of electrolytic and electrothermal manganese, medium carbonaceous ferromarganese, low-sophisticated ligatures based on it.

Of the technical literature, several ways to obtain pure manganese dioxide are known: chemical, hydrometallurgical, pyrohydrometallurgical and pyrograhic.

The main requirements that are presented to chemical methods obtaining manganese dioxide are:

• - efficiency of phosphorus removal and empty breed;
• - simplicity of hardware design;
• - high performance;
• - Accessibility and low cost of reagents.

There is a method of obtaining pure manganese dioxide with a sulfuric acid method. The essence of the method is as follows: a suspension (T: g \u003d 1: 4) is passed through cooked from ore and solution of ore (T: 4), sulfur (SO2) and sulfuric (SO3) anhydrides is passed. The dissolution of these gases in water leads to the formation of sulfur and sulfuric acids. In the sulfuric acid, manganese oxides intensively dissolved to form a manganese salt of dithionic acid and manganese sulfate by reactions: MnO2 + 2SO2 \u003d MNS2O6; MnO2 + SO2 \u003d MNSO4.

In the presence of an excess of calcium dythionate, calcium sulfate is precipitated and manganese dithionate formation: MNSO4 + CAS2O6 \u003d MNS 2O6 + Caso4

The leached pulp is neutralized with lime milk to pH 4-5, then it is aimed for oxidation of iron oxide and sulfur dioxide removal. The sediment falls out: trivalent iron, phosphorus, aluminum, silica. The precipitate is filtered, washed hot water And send to the dump. A manganese is precipitated from the purified solution to the addition of nigged lime, while the calcium dithionate is obtained again, which is returned to the process:

MNS2O6 + SA (OH) 2 \u003d Mn (OH) 2 + CAS2O6.

The precipitate of manganese hydroxide is filtered, washed, dried and calcined. The calcined concentrate contains,%: 92 - MnO2, 1.5 - SiO2, 4.0 - Cao, 0.02 - P2O5 and 0.5-3 - SO 2 (M.I. Gasik. Metallurgy manganese. Kiev: Technique, 1979, p.55-56).

The disadvantages of the known method of obtaining manganese dioxide are:

• - complexity of hardware design;
• - the product is contaminated with a blank breed (SiO2, CaO, etc.);
• - High sulfur concentration in the final product (from 0.5 to 3%).

The closest to the proposed technical essence and the achieved effect is the method of obtaining manganese dioxide by thermal decomposition of manganese nitrate in the presence of calcium, magnesium, potassium and sodium nitrates, according to which the decomposition is carried out at a pressure of 0.15-1.0 MPa (author's certificate No. 1102819, CL. C22B 47/00; C01G 45/02, priority from 20.05.83, publ. 15.07.84, Bul. No. 26).

According to the prototype method, the preparation of manganese dioxide in the presence of calcium, magnesium, potassium and sodium nitrates, decomposition is carried out at a pressure of 0.15-1.0 MPa.

Technological parameters and properties of the prototype method:

• - decomposition temperature, ° C - 170-190;
• - the rate of formation of manganese dioxide, kg / m3h - 500-700;
• - degree of decomposition Mn (NO3) 2,% of the initial number - 78-87;
• - conditions for unloading pulp from the reactor - gravity;
• - moisture content in nitrogen oxides,% - 19-25;
• - energy consumption, MJ / kg - 1.7-2.2;
• - MNO2 content in manganese dioxide,% - 99.5.

The disadvantages of the known method are the low rate of expansion of manganese nitrate, large energy consumption, a high amount of water in the resulting nitrogen oxides.

The objective of the present invention is to simplify the technology of obtaining manganese dioxide, increasing the rate of decomposition and product output.

The task is achieved by the fact that the thermal decomposition process is carried out with a gradual decrease in the pressure in the autoclave, ranging from the pressure of 0.6 MPa and reducing it to the end of the process to 0.15 MPa, while the pulp is continuously treated with a stirrer rotating at a speed of 1-15 about / min; In this case, in the process of thermal decomposition, a vibration with a frequency of 20-50 hertz is imposed on the rotating stirrer.

The upper value of the pressure for the thermal decomposition of nitrates is determined by the conditions for the processing of nitrogen oxides into the acid (it is carried out at a pressure not exceeding 0.6 MPa), and the lower limit is practical expedient. A gradual pressure decrease to 0.15 MPa provides a more complete thermal decomposition of manganese nitrates.

Reducing the rotational speed of the mixer below 1 rpm does not provide a homogeneous pulp solution. An increase in the rotational speed above 15 rpm leads to the bundle of the pulp and the appearance of areas with a higher concentration of water (due to the difference in densities).

Lower vibration frequencies are below 20 hertz, imposed on the mixer, practically do not affect the indicators of the thermal decomposition of manganese nitrate. Increasing the vibration frequency above 50 Hertz is not economically justified.

In compliance with these conditions, not only the rate of decomposition of manganese nitrate is increasing, but the process itself is generally becoming more technologically. It has been established that in the proposed process, the pulp output does not strongly depend on its physical properties, which greatly simplifies the process of its unloading from the reactor, while nitrogen oxides contain lower concentrations of water and can be easily recycled back to acid. Table 1 presents comparative data of technological parameters of obtaining manganese dioxide for the known and proposed methods. Indicators (averaged) according to the proposed method for producing manganese dioxide, presented in Table 8, are taken on the basis of the results of the experiments carried out (Example 1).

Table 8.

Technological parameters and properties
Known	Offered
Decomposition temperature, ° C
Pressure, MPa		Gradual pressure decrease from 0.6 to 0.15
The rate of formation of manganese dioxide, kg / m3h
The time required for the formation of 200 kg of manganese dioxide, h
The degree of decomposition of Mn (NO3) 2, in% of the initial number
Conditions for unloading pulp from the reactor	Self	Self
Energy Costs, MJ / kg MNO2
The speed of rotation of the agitator, r / min.

In terms of thermal decomposition, vibration with a frequency of 30 hertz was imposed on the rotating stirrer - the degree of decomposition Mn (NO3) 2 increases by 2-3.5%.

Physico-chemical properties of powder:

• - density - 5.10 g / cm3;
• - MNO2 content - 99.6 wt.%;
• - the content of Fe is less than 3h10-4 wt.%,
• - content P - no more than 5h10-3 wt.%;
• - N 2O - no more than 3h10-2 wt.%.

Below are examples that do not exclude others in the scope of claims.

In the autoclave, 1.5 kg of a solution of nitrates of the following, wt.%: 40.15 Mn (NO3) 2; 25.7 CA (NO3) 2; 7.3 Mg (NO3) 2; 9.2 KNO3; 5.7 nano3; 15.0 H2O.

The weight of the water removed during thermal decomposition was determined by the difference of its weight in the initial solution and in the liquid phase of the pulp. The number of nitrogen oxides isolated was determined by the stoichiometry of the thermal decomposition of manganese nitrate in accordance with the resulting MNO2. The main results of the experiments are presented in Table 9.

Table 9.

Parameters	Examples of specific execution
Famous way	The proposed method
Defayment temperature, C °
Pressure, MPa *
Rotation speed stirrers, rpm
Vibration frequency, Hz
Decomposition time, min
MnO2 formation rate, kg / m3h
Volume of excreted gases, m3 per 1 kg MnO2
Output of dry dioxide manganese,%
The upper pressure limit for thermal decomposition of nitrates is determined by the conditions for the processing of nitrogen oxides in acid

A manganese dioxide of the following composition was obtained, wt.%: MnO2 - 99.6; R<0,005; S<0,05; SiO2<0,1; (К, Mg, Na, Ca)<0,1.

Thus, the proposed method provides not only a faster decomposition of manganese nitrate, but also greatly simplifies the production technology of MNO2, both at the stage of unloading and at the regeneration stage of nitrogen oxides; At the same time, the costs of redistribution are significantly reduced. The yield of obtained dry dioxide of manganese is 84-92% against 78% (according to the known method) from theoretically possible.

The resulting manganese dioxide is used to smear the metal manganese with an extra-refined process.

The mixture had a composition, kg:

• - MnO2 - 10;
• - Al - 4.9;
• - Sao - 0.6.

Just 15.5 kg.

The mixture was mixed, loaded into a mold mine and set fire to the smelter. The duration of the smelting was 2.4 minutes. Received 5.25 kg of metallic manganese composition. % Mn 98.9; Oll 0,96; P - traces (less than 0.005%) and 9.3 kg of slag composition, weight%: MNO 14.6; Al2O3 68.3; Sao 18.0.

Extraction of manganese into the alloy amounted to 85.0%.

The slag from the smelting of metal manganese can be used as the initial raw material (instead of boxites) upon receipt of aluminum.

The use of the present invention will solve the problem of using significant reserves of poor manganese ores, in particular the carbonate ores of the Usinsky field or iron orders, the enrichment of which by any other ways are currently unprofitable.

The resulting manganese alloys are distinguished by the high concentration of the drive element (manganese) and the low content of harmful impurities (phosphorus and carbon).

The use of manganese ferroalloys during the smelting of high-quality steel grades leads to a decrease in the metal-capacity structures, simplifies the doping process and provides a significant economic effect.

The production of manganese concentrates by chemical methods will significantly reduce the deficit in the country in manganese ferroalloys, and its production can be organized at the chemical plants.

The proposed method for producing manganese dioxide can be organized at enterprises with the ability to dispose of nitrogen oxides.

CLAIM

The method of obtaining manganese dioxide by thermal decomposition, comprising the dissolution of manganese-containing raw materials in nitric acid to obtain a solution of manganese nitrates and nitrates present in the ore of calcium, potassium, magnesium impurities, and the subsequent thermal decomposition of nitrates in the autoclave, characterized in that the thermal decomposition is leading A constant decrease in the pressure in the autoclave, ranging from the pressure of 0.6 MPa and reducing it to the end of the process to 0.15 MPa, while the pulp is continuously treated with a stirrer rotating at a speed of 1-15 rpm and with an imposition of vibration with a frequency of 20 -50 Hz.

experimental part

The above experiments are applied at large enterprises.

I want to consider a laboratory method for producing manganese dioxide in tin dioxide.

Accessories:

• 1. Porcelain Tigel:
• 2. Glass filter.

The essence of the method: obtaining solid oxides by thermal decomposition of the mixture of SNC2O4 * H2O and MNSO4 * 5H2O, calcining in air.

Pre-synthesis SNC2O4 * H2O.

To obtain tin oxalate, 10 g of tin sulphate, 4.975 g of ammonium oxalance were taken. Prepared solutions of both substances, for this tin sulfate was dissolved in 100 ml of water, and ammonium oxalate in 50 ml of water. Then, a solution of ammonium oxalate solution was adhered to the tin sulfate solution. An active precipitation of white fine precipitate was observed (SNC2O4 * H2O). The resulting suspension was filtered on a dense glass filter.

Reaction equation:

SNSO4 * H2O + (NH4) 2C2O4 * H2O\u003e SNC2O4 * H2OV + (NH4) 2SO4 + H2O

As a result, 7.934 g of tin oxalate was obtained, with the estimated mass of 9.675. The reaction yield was 82.0%.

According to the reaction equations

MNSO4 * 5H2O\u003e MNO + SO3 (g) + 5 H2O (g)\u003e MnO2.

SNC2O4 * H2O\u003e SNO + CO2 + H2O\u003e SNO2

A) 7.5% MNO2 / 92.5% SNO2.

To receive it, they took: 0.75 g. SNC2O4 * H2O, 0.07 MNSO4 * 5H2O. (Since the number of manganese sulphate was significantly less than the amount of ammonium oxalate, to achieve a greater homogeneity of the mixture after placing it in the porcelain crucible, several drops of water were added. Then the mixture was hampered on the burner.). The calcination mode of 900 ° C 2 hours did not give results (a grayish-cream color of the mixture is preserved). As a result of calcination at 1200 ° C 2 hours, the sample has purchased a bright red color. Sample weight 0.5 g

• B) 15% MnO2 / 85% SNO2. (0.761 SNC2O4 * H2O, 0.088 MNSO4 * 5H2O) Mass sample 0.53
• C) 22% MnO2 / 78% SNO2. (0.67 SNC2O4 * H2O, 0.204 MNSO4 * 5H2O). Mass sample 0.52
• D) 28% MnO2 / 72% SnO2 (0.67 SNC2O4 * H2O, 0.2911 MNSO4 * 5H2O). Mass sample 0.56

Manganese Oxide (II) - MNO - lower manganese oxide, monoxide.

Basic oxide. Not soluble in water. It is easily oxidized to form a fragile shell MNO 2. It is restored to manganese when heated with hydrogen or active metals.

Oxide of manganese (II) can be obtained by calcining at a temperature of 300 ° C oxygen-containing salts of manganese (II) in an atmosphere of inert gas. It is obtained from a common MNO 2 through a partial reduction at temperatures of 700-900 ° C with hydrogen or carbon monoxide.

Manganese hydroxide (II) - inorganic compound, manganese metal hydroxide with Mn (OH) 2 formula, light-pink crystals that are not soluble in water. Exhibits poorly basic properties. Oxidized in air.

Manganese hydroxide (II) is formed when the interaction of it with alkalis salts is interacted:

Chemical properties.

· Manganese hydroxide (II) is easily oxidized in air to the brown oxohydroxide manganese, which is further decomposed on manganese oxide (IV):

· Manganese hydroxide (II) has basic properties. It reacts with acids and acidic oxides:

· Manganese hydroxide (II) has restorative properties. In the presence of strong oxidants, it can oxidized to permanganate:

Manganese oxide (III) - Inorganic compound, manganese metal oxide with Mn 2 O 3 formula, brown-black crystals, not soluble in water.

Getting.

· In nature, Minerals Braunit, Kurnakit and Buxbiite - manganese oxide with various impurities.

· Oxidation of manganese oxide (II):

· Manganese oxide recovery (IV):

Chemical properties.

· Decomposes when heated:

· When dissolved in acids - disproportionates:

· When fusing with metal oxides, monganitis salts are formed:

Not dissolved in water.

Manganese hydroxide (III) –Mn 2 O 3ּ H 2 O.or MNO (OH)meets in nature in the form of a mineral manganita(drowning manganese ore). Artificially obtained manganese hydroxide (III) is used as black and brown paint.

When interacting with acid oxidizers is formed salt manganese.

Marganese (II) salts are usually soluble in water, except Mn 3 (PO 4) 2, MNS, MNCO 3.

Manganese sulfate(Ii) MNSO 4 - Salt white colorOne of the most stable manganese compounds (II). The MNSO 4 7N 2 O crystal hydrate is found in nature. It is used with the dye of tissues, as well as along with manganese chloride (II) MNSL 2 - to obtain other manganese compounds.

Carbonate manganese(Ii) MNSO 3 is found in nature in the form of manganese pshat and is used in metallurgy.

Nitrate manganese(Ii) Mn (NO 3) 2 is obtained only by artificially and is used to separate rare-earth metals.

Marganese salts are the catalysts of oxidative processes occurring with the participation of oxygen. They are used in sequivat. Linseed oil with the addition of such a sequeant is called Olifa.

Manganese oxide (IV) (manganese dioxide) MNO 2 - Dark brown powder, insoluble in water. The most sustainable manganese compound, widespread in earth Kore (Mineral pyrolusitis).

Chemical properties.

Under normal conditions, it behaves quite inert. When heated with acids, oxidative properties exhibit, for example, oxidizes concentrated hydrochloric acid to chlorine:

With sulfur and nitric acids MnO 2 decomposes with oxygen release:

When interacting with strong oxidizers, manganese dioxide is oxidized to Mn 7+ and Mn 6+ compounds:

Manganese dioxide manifests amphoteric properties. Thus, when oxidizing the sulfate solution of salt MNSO 4 permanganate potassium in the presence of sulfuric acid is formed a black precipitate of Mn salt (SO 4) 2.

And when fusing with alkali and the main oxides, MNO 2 acts as acid oxide, forming a salt - manganites:

It is a catalyst for decomposition of hydrogen peroxide:

Getting.

In the laboratory conditions are obtained by thermal decomposition of potassium permanganate:

Also possible to obtain potassium permanganate reaction with hydrogen peroxide. In practice, the formed MNO 2 catalytically decomposes hydrogen peroxide, as a result of which the reaction does not pass to the end.

At temperatures above 100 ° C restoration of potassium permanganate hydrogen:

64. MARGANT (VI) compounds, methods for obtaining and properties. Manganese oxide (VII), manganese acid and permanganate - receipt, properties, application.

Manganese oxide (VI) - Inorganic compound, oxidized manganese metal with MNO 3 formula, dark-red amorphous substance, reacts with water.

It is formed during the condensation of purple vapors, highlighted when the solution of potassium permanganate in sulfuric acid is heated:

Chemical properties.

· Decomposes when heated:

· Reacts with water:

· With alkalis forms salts - manganats:

Manganese hydroxide (VI) Shows acidic character. Free manganese (VI) Acid is unstable and disproportionates in an aqueous solution according to the scheme:

3H 2 MNO 4 (B) → 2HMNO 4 (B) + MNO 2 (T) + 2H 2 O (g).

Manganats (VI) They are formed when weaving manganese dioxide with a pitch in the presence of oxidants and have emerald-green color. In a strongly alkaline medium, manganate (VI) is quite stable. When diluting alkaline solutions, hydrolysis occurs, accompanied by disproportionation:

3K 2 MNO 4 (B) + 2H 2 O (g) → 2kmno 4 (c) + MnO 2 (T) + 4Koh (B).

Manganats (VI) - strong oxidizing agents that are restored in an acidic medium to Mn (II),and in neutral and alkaline media - to MNO 2.Under the action of severe manganate oxidants (VI) can be oxidized to Mn (VII):

2K 2 MNO 4 (B) + Cl 2 (g) → 2kmno 4 (B) + 2KCl (B).

When heated above 500 ° C Manganat (VI) disintegrates:

manganat (IV) and oxygen:

2K 2 MNO 4 (T) → K 2 MNO 3 (T) + O 2 (g).

Manganese oxide (VII) Mn 2 O 7 - greenish-brown oil liquid (T pl \u003d 5.9 ° C), unstable at room temperature; Strong oxidizing agent, when contacting with combustible substances ignites them, possibly with an explosion. Explodes from shock, from a bright flash of light, when interacting with organic substances. To obtain manganese oxide (VII) Mn 2 O 7 can be an action of concentrated sulfuric acid to potassium permanganate:

The resulting manganese oxide (VII) is unstable and decomposed on manganese oxide (IV) and oxygen:

At the same time, ozone stands out:

Manganese oxide (VII) interacts with water, forming manganese acid, which has a purple-red color:

Anhydrous manganese acid could not be obtained, in solution it is resistant to a concentration of 20%. it highly silty acid , The seeming degree of dissociation in a concentration solution of 0.1 mol / dm 3 is 93%.

Permanganic acid – strong oxidizer . I interact even more energetically Mn 2 O 7, flammable substances in contact with it are flammable.

Marganese acid salts are called permanganats . The most important of them is permanganate potassium, it is a very strong oxidant. With its oxidative properties in relation to organic and inorganic substances, it is often necessary to meet in chemical practice.

The degree of recovery permanganate-ion independent of the nature of the environment:

1) Sour Wednesday Mn (II) (salts of Mn 2+)

MNO 4 - + 8H + + 5ē \u003d Mn 2+ + 4H 2 O, E 0 \u003d +1.51 B

2) Neutral Wednesday Mn (IV) (manganese oxide (IV))

MNO 4 - + 2H 2 O + 3C \u003d MNO 2 + 4OH -, E 0 \u003d +1.23 B

3) Alkaline Environment Mn (VI) (manganats M 2 MNO 4)

MnO 4 - + ē \u003d MnO 4 2-, e 0 \u003d + 0.56b

As can be seen, the strongest oxidative properties of permanganages show in an acidic environment.

The formation of manganats occurs in a strongly alcoholic solution, which ensures hydrolysis suppression K 2 MNO 4. Since the reaction usually passes into sufficiently diluted solutions, the end product of the recovery of permanganate in an alkaline medium, as in neutral, is MNO 2 (see Disproportionation).

At a temperature of about 250 o, potassium permanganate decomposes according to the scheme:

2kmno 4 (T) K 2 MNO 4 (T) + MNO 2 (T) + O 2 (g)

Potassium permanganate is used as an antiseptic agent. The aqueous solutions of its different concentrations from 0.01 to 0.5% are used for wound disinfection, throat rinsing and other anti-inflammatory procedures. Successful 2 - 5% Potassium permanganate solutions are used when skin burns (the skin is dry, and the bubble is not formed). For living organisms, permanganages are poisons (cause coagulation of proteins). Their neutralization is produced by 3% solution. H 2 O 2acidified acetic acid:

2kmno 4 + 5n 2 O 2 + 6CN 3 Soam → 2mn (CH 3 SOO) 2 + 2 SO 3 COI + 8H 2 O + 5O 2

65. Compounds of Rhenium (II), (III), (VI). Compounds of rhenium (VII): oxide, rhenium acid, perrynates.

Oxide Rhenium (II) - an inorganic compound, oxidized metal from the REO formula, black crystals that are not soluble in water forms hydrates.

The hydrody hydrate Reo H 2 O is formed when the rhenium acid cadmium is restored in an acidic environment:

Oxide Rhenium (III) - an inorganic compound, oxide of metal with a formula Re 2 O 3, black powder, not soluble in water, forms hydrates.

Obtain hydrolysis of chloride (III) in an alkaline environment:

Easily oxidized in water:

Oxide Rhenium (VI) - inorganic compound, metal oxide with REO 3 formula, dark-red crystals that are not soluble in water.

Getting.

· Condrectional of oxide (VII):

· Restoration of oxide (VII) carbon monoxide:

Chemical properties.

· Decomposes when heated:

· Oxisses concentrated nitric acid:

· With hydroxides alkali metals Forms reniths and perrynates:

· Oxidizes air oxygen:

· Restored by hydrogen:

Oxide Rhenium (VII) - inorganic compound, metal oxide with formula Re 2 O 7, light yellow hygroscopic crystals dissolve in cold water, reacts with hot.

Getting.

· Metal oxidation:

· Decomposition when heating oxide (IV):

· Oxidation of oxide (IV):

· Decomposition when heated with rhenium acid:

Chemical properties.

· Decomposes when heated:

· Reacts with hot water:

· Reacts with alkalis to form perrrenates:

· Is the oxidant:

· Restored by hydrogen:

· Corporates with rhenium:

· Reacts with carbon monoxide:

Rhenium acid - an inorganic compound, oxygen-containing acid with the formula HREO 4, exists only in aqueous solutions, forms salts perenaty.

Translation from low-soluble compounds, such as REO and RES2, is carried out into the solution with acid decomposition or alkaline fusion to form soluble perrynates or rhenium acid. Conversely, the extraction of solutions from solutions is precipitated in the form of potassium, cesium, thallium, thalnia, and others. A large industrial importance is an ammonium perrrenate, from which metallic rhenium is obtained by hydrogen.

Rhenium acid is obtained by dissolving RE2O7 in water:

RE2O7 + H2O \u003d 2HREO4.

Renielic acid solutions were also obtained by dissolving metallic rhenium in hydrogen peroxide, bromo water and nitric acid. Excess peroxide is removed with boiling. Rhenium acid is obtained by oxidizing lower oxides and sulphides, from perrynotes using ion exchange and electrodialysis. For convenience in Table 2 shows the values \u200b\u200bof density solutions of rhenium acid.

Rhenium acid is stable. In contrast to chlorine and manganese acids, it has very weak oxidative properties. Her restoration is usually slow. Metal amalgams are used as reducing agents, chemical agents.

Perrynaments are less soluble and thermally more stable than the corresponding perchlorates and permanganages.

Perenats and potassium, cesium, rubidium and potassium have the smallest solubility.

Perenats TL, RB, CS, K, AG - low-soluble substances, perrynaments, Ba, Pb (ii) have an average solubility, perrynaires Mg, Ca, Cu, Zn, CD, and the like. Very well dissolve in water. In the composition of potassium per raintes and ammonium rhenium is distinguished from industrial solutions.

Potassium perrrenate Kreo4 is small colorless hexagonal crystals. It melts without decomposition at 555 °, at a higher temperature disappears, partially dissociating. Solubility of salt in an aqueous solution of rhenium acid is higher than in water, whereas in the presence of H2SO4 it practically does not change.

Ammonium perrrenate NH4REO4 is obtained by neutralizing with an angular acid ammonia. Compared well soluble in water. When crystallization of solutions, continuous solid solutions forms with KREO4. When heating in air is decomposed, starting from 200 °, giving the abbreviation containing RE2O7 and black residue REO2. In the expansion in the inert atmosphere, only oxide (IV) for the reaction is formed:

2NH4REO4 \u003d 2REO2 + N2 + 4H2O.

When the salt is restored with hydrogen, metal is obtained.

From the salts of rhenium acid with organic bases, we note the Nitron Prenate C20H17N4REO4, which has a very small solubility in acetate solutions, especially in the presence of an excess of nitron acetate. The formation of this salt is used to quantify rhenium.

The author of the Chemical Encyclopedia G.R. I.L. Knununz

Manganese oxide: MNO, MN 2 O 3, MNO 2, MN 3 O 4, MN 2 O 7, MN 5 O 8. In addition to Mn 2 o 7, all oxides are crystals, not soluble in water. When heating the highest oxides, it is cleaved about 2 and lower oxides are formed:

When withstanding in air or in the atmosphere of 2 above 300 ° C, MNO and MN 2 O 3 are oxidized to MNO 2.

Anhydrous and hydraigh. MN oxides are part of manganese and iron-manganese ores in the form of pyrolusion minerals B -mno 2, ppi-mamm * nmNo 2 * XN 2 O [MN \u003d BA, CA, K, MN (H)], manganita B -mnooh (Mn 2 O 3 * H 2 O), G -MNOOH grott, 3mn 2 O 3 * MNSIO 3 and others. With MNO content 2 60-70%. Processing of manganese ores includes wet enrichment and subsequent chemical release of MNO 2 or Mn 2 oxides, 3 methods of sulfitization and sulfatization, carbonization, will restore. firing and others.

MNO monoxide (MANGANOZIT mineral). Up to - 155.3 ° С Resistant hexagon. Modification, above - cubic (see Table). Semiconductor. Antiferromagnet with a point of Neale 122 K; Magn. susceptibility + 4.85 * 10 - 3 (293 K). Has poorly-home properties; Restores to Mn hydrogen and active metals when heated. With the interaction of MNO with acids, Mn (II) salts are formed, with a NaOH melt at 700-800 ° C and an excess O 2 - Na 3 MNO 4, under action (NH 4) 2 S - MNS sulfide. Receive the decomposition of Mn (OH) 2, Mn (C 2 O 4), Mn (NO 3) 2 or MNCO 3 in an inert atmosphere at 300 ° C, controlled by the reduction of MNO 2 or Mn 2 O 3 hydrogen or Co at 700-900 ° FROM. Component of ferrite and other ceramic. Materials, slag for desulfurization of metals, microfertilizers, catalyst for dehydrogenation of piperidine, antiferromagna. material.

SSVSVIXID MN 2 O 3 exists in two modifications - rhombic. a (Mineral Kurnakit) and Cube. b (bixbite mineral), transition temperature a : B 670 ° C; Paramagnetic, Magn. susceptibility +1.41 10 - 5 (293 K); It is restored by H 2 at 300 ° C to MNO, aluminum when heated - to Mn.

Under the action diluted H 2 SO 4 and HNO 3 passes into MNO 2 and salt Mn (II). Get Mn 2 about 3 thermodynamically decomposition MNO.

Manganese Oxide (II, III) Mn 3 O 4 (Gausmanit Mineral); A -MN 3 O 4 at 1160 ° C passes to B -mn 3 O 4 with cubic crystal. grille; D H 0 Transition A : B 20.9 kJ / mol; Paramagnetic, Magn. susceptibility + 1.24 * 10 - 5 (298 K). Exhibits chemical properties inherent in MNO and MN 2 O 3.

MNO 2 dioxide is the most common MN connection in nature; The most resistant b -modification (mineral pyrolusitis). Knobich are known. G -mno 2 (Mineral Ramsident, or Polyanitis), as well as a, d and e, considered as solid solutions various shapes MNO 2. Paramagnetic, Magn. susceptibility + 2.28 * 10 - 3 (293 K). Mn - nontechiometric dioxide. Connection, in its lattice there is always a lack of oxygen. Amphoterren. H 2 to MNO is restored at 170 ° C. When interacting with NH 3, H 2 O, N 2 and MN 2 O 3 are formed. Under the action of 2 in the NaOH melt gives Na 2 MNO 4, in the environment. Acids are the corresponding salts of Mn (IV), H 2 O and 2 (or CL 2 in the case of hydrochloric acid). Receive MNO 2 decomposition of Mn (NO 3) 2 or Mn (O) 2 at 200 ° C in air, the reduction of KMNO 4 in the neutral medium, the electrolysis of Mn (II) salts. Apply to obtain Mn and its connection, sequivans, as a depolarizer in dry elements, a brown pigment component (UMBR) for paints, for clarifying glass, as a reagent for detecting CL -, oxidizer in Zn, Cu, U hydrometallurgia, catalyst component in gopcalite cartridges et al. Active MNO 2, Received aqueous solutions MNSO 4 and KMNO 4, -Oxider in organic chemistry.

Manganese oxide (VII) Mn 2 O 7 (Dimarganic heptaoxide, manganese anhydride) - Oil green liquid; Melting point is 5.9 ° C; 2.40 g / cm density 3; D H 0 OBR -726.3 kJ / mol. Above 50 ° C with slow heating begins to decompose with the release of 2 and the formation of lower oxides, and with more high temperatures or high heating rates explodes; It is extremely sensitive to mechanical and thermal influences. Strong oxidizer; When contacting Mn 2 O 7, combustible substances are ignited. Manganese Oksidib. Received when interacting KMNO 4 with H z SO 4 on cold.

Mn 5 O 8, or Mn 2 II (Mn IV O 4) 3 (MN IV O 4) 3, is a solid; not soluble in water; can be obtained by oxidation of MNO or Mn 3 O 4; Easy decomposes on MNO 2 and 2.

Mn stoichiometric hydroxides. The connection is only Mn (OH) 2, MNO (OH) and HMNO 4, others are a hydracy. variable composition oxides close chemical properties relevant oxides. Acidic properties of hydroxides increase with an increase in the degree of oxidation Mn: Mn (OH) 2< MnО(ОН) (или Mn 2 O 3 * xH 2 O) < MnO 2 * xН 2 О < Mn 3 О 4 * xН 2 О < Н 2 MnО 4 < НMnО 4 . Гидроксид Мn(II) практически не растворим в воде (0,0002 г в 100 г при 18 °С); основание средней силы; растворим в растворах солей NH 4 ; на воздухе постепенно буреет в результате окисления до MnО 2 * xН 2 О.

Mn (III) hydroxyoxide MnO (OH) is known in two modifications; At 250 ° C in vacuo, it is dehydrated to G -mn 2 O 3; In water is not suited. Pri Manganit does not decompose HNO 3 and diluted H 2 SO 4, but slowly reacts with H 2 SO 3, artificially obtained is easily decomposed with mineral acids; Oxides 2 to b -mno 2. See also Manganats.

Manganese Oksidio. toxic; MPC see in Art. Manganese.

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Belongs to the VII group. Located in the fourth period between chromium and iron. It has the 25th atomic number. Formula manganese 3D 5 4s 2.

It was opened in 1774. Atom manganese Weighs 54,938045. Contains isotope 55mn, and natural manganese It consists entirely of it. The degree of metal oxidation varies from 2 to 7. Electricity Mn - 1.55. Transition material.

Connections manganese 2.form oxide and dioxide. Show the basic properties of the element. Education manganese 3 and manganese 4.different amphoteric properties. In the combinations of metal 6 and 7, the properties lead acid manganese. Element number 25 forms numerous types of salts and various binary compounds.

The mining mining is carried out everywhere in Russia and in the near abroad. Ukraine has a special Manganese - cityLocated on numerous formations of manganese ore.

Manganese description and properties

Silver-white color with a slight gray raid highlights manganese. Structure The element has an admixture of carbon, which gives it silver-white color. It exceeds iron by hardness and fragility. In the form of small abrasives Pyroforen.

When interacting with the air environment occurs oxidation of manganese. Is covered by an oxide film that protects it from the subsequent oxidative reaction.

It dissolves in water, completely absorbs hydrogen, without joining the reaction with it. In the process of heating combines oxygen. Actively reacts with chlorine and gray. When interacting with acid oxidizers forms salt manganese.

Density - 7200 kg / m3, t melting - 1247 ° C, T boiling - 2150 ° C. Specific heat capacity - 0.478 kJ. Has electrical conductivity. Contacting chlorine, bromine and iodine forms digaloids.

At high temperatures, interact with nitrogen, phosphorus, silicon and boron. S. slowly interacts cold water. In the process of heating, the reactivity of the element increases. Mn (OH) 2 and hydrogen is formed at the output. When a manganese compounds with oxygen formed oxide manganese. Seven of its groups are distinguished:

Manganese oxide (II). Monoxide. Does not interact with water. It is easily oxidized, forming a fragile crust. When heated with hydrogen and metals of the active group is restored to manganese. It has green and gray-green crystals. Semiconductor.

Manganese oxide (II, III). Brown crystals - black MN3O4. Paramagnetic. In the natural environment, it is found as Mineral Gausmanit.

Manganese oxide (II, IV). Compound inorganic MN5O8 character. May be considered as ortomanganit Manganese. Not dissolved in H 2 O.

MARGANT (III) oxide. Brown-black-black Mn2O3 blackstalls. Do not react with water. It is found in the natural environment in Minerals Braunit, Kurnakit and Bixbit.

Manganese oxide (IV) or manganese dioxide MNO2. Insoluble in the water of a dark brown tint powder. Sustainable manganese education. Contained in the mineral pyro-monuite. Absorbs chlorine and salts of heavy metals.

Manganese oxide (VI). Dark red amorphous element. Reaches water. Fully decomposes when heated. Alkaline reactions form salt sediments.

Manganese oxide (VII). Oil greenish-brown liquid Mn2O7. Strong oxidizer. When contacting flammable mixtures, instantly ignites them. It can explode from the push, sharp and bright flash of light, interacting with organic components. When interacting with H 2 O forms manganese acid.

Marganese salts are the catalysts of oxidative processes occurring with the participation of oxygen. They are used in sequivat. Linseed oil with the addition of such a sequeant is called Olifa.

Application manganese

Mn is widely used in ferrous metallurgy. Add alloy iron Marganese (Ferromargana). The share of manganese in it is 70-80%, carbon 0.5-7%, the rest falls on iron and extraneous impurities. The element number 25 in stalk connects oxygen and sulfur.

Mixes are used chrome - Marganese, Martan, Silicon-Marganese. In the production, there were no manganese alternative replacement.

Chemical element Performs many functions, including refining and deoxides steel. Technology is widely used zinc Marganese. The solubility of Zn in magnesium is 2%, and the strength of steel, in this case, increases to 40%.

In the domain mine, Manganese removes a sulfur raid from cast iron. The technique uses the triple alloys of manganins, where it comes manganese copper and nickel. The material is characterized by a large electron resistance on which there is no temperature affects, but the power of pressure.

Used to make pressure gauges. Present value for industry is copper alloy - manganese. Content Manganese here 70%, copper 30%. It is used to reduce harmful production noise. In the manufacture of explosion-packages for festive activities, a mixture is used, which includes such elements as magnesium Marganese. Magnesium is widely used in aircraft industry.

Some types of manganese salts, such as KMNO4 have found their use in the medical industry. Potassium permanganate refers to manganese salts. It has the form of dark purple. Dissolves in aquatic environment, painting it in purple color.

It is a strong oxidizing agent. Antiseptic, has antimicrobial properties. Manganese in waterit is easily oxidized, forming a poorly soluble manganese oxide brown.

In contact with the tissue protein, compounds with pronounced knitting qualities. In high concentrations mANGAND SOLUTIONit has an annoying and migratory action.

Potassium manganeseused to treat certain diseases and to provide first aid, and a bubble with manganese crystals is in each aid kit.

Manganese is useful for human health. Participates in the formation and development of the cells of the central nervous system. Promotes the absorption of vitamin B1, and iron. Regulates blood sugar content. Provided in the construction of bone tissue.

Participates in the formation of fatty acids. Improves reflex abilities, memory, removes nervous tension, irritability. Absorbing in the intestinal walls manganese, vitamins In, e, phosphorus, calcium strengthen this process, affects the body and metabolic processes in general.

Minerals, indispensable for man, such as calcium, Magnesium, Manganese, Copper, potassium, iron add to vitamin and mineral complexes to eliminate vitamin deficit.

Also microelements zinc, Manganese and iron play a huge role in the life of plants. Parts are included in phosphoric and mineral fertilizers.

Price manganese

Metal manganese contains up to 95% of pure manganese. It is used in the steelmaking metallurgical industry. Removes from steel unnecessary impurities and gives it by alloying qualities.

Ferromargananets is used to deoxine the alloy during the melting process, by removing oxygen from it. Binds sulfur particles with each other, improving high-quality steel characteristics. Manganese strengthens the material, makes it more wear-resistant.

Metal is used when creating ball mills, earthmoving and stonecrew machines, armored elements. Mangadine's alloy make risostats. Element number 25 is added to bronze and.

The large percentage of manganese dioxide is consumed to create galvanic elements. With the addition of MN is activated in a thin organic and industrial synthesis. Compounds MnO2 and KMNO4 are oxidizing.

Manganese - substance Indispensable in ferrous metallurgy. Unique in its physical and chemical characteristics. Manganese to buy You can in specialized outlets. Five kilograms of metal costs about 150 rubles, and ton, depending on the type of connection, costs about 100-200 thousand rubles.

Manganese dioxide (MNO 2) or manganese oxide (IV) is a dark gray substance. When heated in air to 530 degrees. With manganese dioxide decomposes, highlighting oxygen as shown above. In vacuum or in the presence of a reducing agent, this reaction proceeds significantly more intense.

When boiling, manganese dioxide with concentrated nitric acid is formed by a solder of manganese (II) and oxygen is distinguished:

2 mno 2 + 4 NNO 3 \u003d 2 Mn (NO 3) 2 + 2 H 2 O + O 2.

Manganese dioxide in an acidic environment shows oxidative properties:

Mno 2 + 4 nsl \u003d mnsl 2 + Sl 2 + 2 H 2 o;

MNO 2 + 2 FESO 4 + 2 H 2 SO 4 \u003d MNSO 4 + Fe 2 (SO 4) 3 + 3 H 2 O.

When weaving the oxide of manganese (IV) with alkalis without air access, manganite or manganate (IV) is formed:

2 mno 2 + 2 Kon \u003d K 2 mno 3 + H 2 O.

In the presence of oxygen air playing the role of the oxidizing agent, the melting is formed by the MANGANAT salt (VI):

2 mno 2 + 4 Kone + O 2 \u003d 2 K 2 mno 4 + 2 H 2 O.

Potassium manganate (K 2 MNO 4) spontaneously decomposes into potassium permanganate and manganese dioxide:

3 to 2 mno 4 + 2 H 2 O \u003d 2 kmNo 4 + mno 2 + 4 con.

Permanganate potassium (kmno 4) is widely used in laboratory practice, industry, medicine and everyday life. It is a very strong oxidizing agent. Depending on the medium, the manganese in the presence of the reducing agent can be recovered to varying degrees of oxidation. In an acidic environment, it is always restored to Mn (II):

2 kmNo 4 + 10 kVr + 8 H 2 SO 4 \u003d 2 MNSO 4 + 6 K 2 SO 4 + 5 VR 2 + 8N 2 O.

The potassium manganate (K 2 mno 4) and manganese dioxide behave similarly.

In an alkaline medium, potassium permanganate is restored to manganate:

2 kmNo 4 + K 2 SO 3 + 2 Kon \u003d K 2 SO 4 + 2 K 2 MNO 4 + H 2 O.

In a neutral or weakly alkaline medium, potassium permanganate is restored to manganese dioxide:

2 kmNo 4 + C 6 H 5 CH 3 \u003d 2 KON + 2 MNO 2 + C 6 H 5 Soam;

2 kmNo 4 + 3 mnso 4 + 2 H 2 O \u003d 5 mno 2 + K 2 SO 4 + 2 H 2 SO 4.

The last reaction is used in analytical chemistry With a quantitative determination of manganese.

Previously, potassium permanangat was obtained by oxidation or manganese dioxide, or potassium manganate. Manganese dioxide oxidized with alkali fusing:

MNO 2 + KNO 3 + 2 KON \u003d K 2 MNO 4 + KNO 2 + H 2 O.

The resulting potassium manganate in the solution spontaneously decayed to permanganate potassium and manganese dioxide:

3 K 2 MNO 4 + 2 H 2 O \u003d 2 kmNo 4 + MNO 2 + 4 con.

According to the second method, Manganat Potassium oxidated with chlorine:

2 K 2 MNO 4 + SL 2 \u003d 2 kmNo 4 + 2 ksl.

Currently, potassium permanganate is obtained by electrolytic manganate oxidation:

MnO 4 2- - e - \u003d mno 4 -.

Potassium permanganate is widely used both in industry and in laboratory practice. It is used for whitening cotton, wool, spinning fibers, oil lightening and oxidation of various organic substances. In laboratory practice, it is used to obtain chlorine and oxygen:

2 kmno 4 + 16 nsl \u003d 2 ksl + 2 mnsl 2 + 5 Cl 2 + 8 H 2 O;

2 kmNo 4 \u003d K 2 mno 4 + MNO 2 + O 2.

In analytical chemistry, potassium permanganate is used to quantify substances with reducing properties (Fe 2+, Sn 2+, ASO 3 3+, H 2 O 2, etc.). This method of analysis is called permanganateometry.