How is iron made, and how is iron made into steel?

The process of refining metallic iron from iron-bearing minerals (mainly iron oxides) is called ironmaking, and there are mainly blast furnace method, direct reduction method, melt reduction method, and plasma method. Blast furnace ironmaking is commonly used in factories!

Blast furnace ironmaking refers to the smelting of iron ore, coke, carbon monoxide, hydrogen and other fuels and fluxes (theoretically speaking, iron can be smelted at high temperature by mixing metals and ores with activity more than iron) into blast furnaces to remove impurities and obtain metallic iron (pig iron).

Its reaction formula is:

Fe2O3+3Co==2Fe+3CO2 (high temperature), Fe3O4+2Co==3Fe+2CO2 (high temperature), C+O2==CO2 (high temperature).

c+CO2==2CO (high temperature).

How steel is made.

Put the pig iron used for steelmaking into the steelmaking furnace for smelting, and then cast the molten steel into shape, and after cooling, it will obtain steel ingots or continuous casting or direct casting into various steel castings.

Pig iron with 2% carbon content is extracted from iron ore (that is, hematite, siderite, magnetite, etc.), and then the excess carbon and other impurities are oxidized into gas or slag at high temperatures with oxidant, and the oxygen top blowing converter is generally used to make steel (oxygen blowing method) to transform it into carbon-containing steel.

In the steelmaking process, silicon, manganese, aluminum and other alloys are added as deoxidizers to adjust the composition of the molten steel to make steel that meets the specifications. At the same time, some necessary elements can be added to make it an alloy with various excellent properties.

Steel is a general term for iron-carbon alloys with a carbon content and mass percentage between to. The chemical composition of steel can vary greatly, and steel that contains only carbon elements is called carbon steel (carbon steel) or ordinary steel; In actual production, steel often contains different alloying elements according to different uses, such as: manganese, nickel, vanadium and so on.

Steelmaking process composition control:

Ensure that all the components of the finished steel meet the requirements of the standard. Composition control is present throughout the process, from batching to tapping, but the focus is on the control of the alloying element composition during alloying. For high-quality steel, it is often required to precisely control the composition within a narrow range; Generally, under the premise of not affecting the properties of steel, it is controlled by the middle and lower limits.

At the end of the blowing process, the silicon content in the molten steel is extremely low. In order to meet the requirements of each steel grade for silicon content, a certain amount of silicon must be added in the form of alloy materials. In addition to being used as a deoxidizer to consume part, it also increases the silicon in the molten steel.

The amount of silicon added should be calculated accurately and should not exceed the allowable range of blown steel grades.

There are many kinds of smelting methods, to choose according to the different ores, but basically can be classified as reduction method, if it is hematite, its main component is Fe2O3, after the ore is sorted, it enters the smelting furnace, and is reduced to crude iron through coke, and then refined, if it is pyrite, it must be calcined first, so that it is converted into Fe2O3, and then smelted by reduction method. In short, there are various smelting methods depending on the ore, but the basic principle is to reduce Fe2O3 with carbon.

Because Fe in the ore is +2 or +3 valence, ironmaking is actually a process of reducing iron to 0 valence Fe element with coke (C) at high temperatures, of course, in order to remove impurities such as silicon and aluminum in iron ore, it is also necessary to add some limestone (CaCO3) and other slags with a specific gravity less than iron (floating on liquid iron), and the molten iron can be made into iron plates, wire rods and other commodities after steelmaking refining, casting or calendering.

Iron ore is an important raw material for iron and steel production enterprises, and natural ore (iron ore) is gradually selected through crushing, grinding, magnetic separation, flotation, gravity separation and other procedures. Iron ore is an aggregate of minerals containing iron elements or iron compounds that can be economically utilized.

Iron is extracted from iron ore and decomposed by melting ore at high temperatures.

Iron is a common metal element and an indispensable raw material for the industrial sector.

How iron is made How iron is refined.

The process of refining iron is called ironmaking, which is the process of refining metallic iron from iron-bearing minerals, and generally uses the blast furnace method to make iron. The main raw materials for ironmaking are iron ore, coke, limestone, and air. The iron content of iron ore is called grade, which must be beneficiated before smelting, removing other impurities, improving the grade of iron ore, and then crushing, grinding and sintering before it can be sent to the blast furnace for smelting.

During smelting, iron ore, coke, and limestone are added from the top of the furnace inlet, and hot air is blown into the furnace from the bottom to the top of the air inlet, and at high temperatures, the reactants are fully in contact with the reaction to obtain iron.

How iron is made How iron is refined.

In actual production, pure iron does not exist, and what is obtained is an iron-carbon alloy.

The method of refining iron is as follows:

The process of refining metallic iron from iron-containing minerals (mainly iron oxides) mainly includes blast furnace method, direct reduction method, melt reduction method, and plasma method.

1.Load the high-purity micronized -Fe2O3 into a dish, and the powder layer should not be too thick. After the disc is placed into the reaction tube, high-purity nitrogen is introduced to completely displace the air. Hydrogen saturated with water is then slowly fed through a gas washing cylinder.

The heating temperature is 300 400 . After the confirmation reaction was completed for 1 3 h, the hydrogen gas was stopped, and the sample was taken out after replacing it with nitrogen.

If the amount of water vapor is insufficient, the heating temperature is too high or the reduction is excessive, FEO will be generated, and the amount of water vapor can be increased by increasing the temperature of the gas washing cylinder (40 60 is more appropriate).

With needle-FeO(OH) as the starting material, -Fe2O3 was obtained by heating and dehydration. With this -Fe2O3, needle-like ferric oxide ions can be prepared. Black tapes use this ferric tetroxide as the tape recording medium.

2.Iron filings are reacted with sulfuric acid to obtain ferrous sulfate, and then caustic soda and iron oxide are added to 95 105 for addition reaction to generate ferric tetroxide, which is filtered, dried and crushed to obtain iron oxide black.

3.By heating an aqueous solution containing ferrous hydroxide precipitate to more than 70 and carrying out slow oxidation, an iron oxide powder composed of a fairly uniform octahedron or cubic single crystal particle with an edge length can be obtained. It is also possible to use the conveying air bubbles as a means of oxidation.

It is also possible to use an oxidizing agent like KNO3.

4.220g of 20% ammonia was added to FeSO4·7H2O aqueous solution, boiled under the condition of air cut off (a round-bottomed flask with a capillary tube can be used), and a concentrated aqueous solution containing KNO3 was added to the boil.

5.Ferrous sulfate solution is oxidized with alkali or the solution of iron salt and ferrous salt is mixed in a certain proportion and then precipitated by alkali.

The method by which iron is made is as follows:

The main raw materials for ironmaking are iron ore, coke, limestone, air, and iron ore includes hematite and magnetite. The iron content of iron ore is called grade, and it must be beneficiated before smelting to remove other impurities and improve the grade of iron ore. It is then crushed, ground and sintered before it can be sent to the blast furnace for smelting, and the role of coke is to provide heat and produce carbon monoxide, the reducing agent.

Limestone is used to remove gangue from slag and smelt to separate the iron produced by smelting from impurities. The main equipment for ironmaking is the blast furnace, in which iron ore, coke, and limestone are fed from the top of the furnace inlet. At the same time, hot air is blown into the furnace from the bottom to the top from the air inlet, and at high temperature, the reactants are fully contacted to react to obtain iron.

Blast furnace ironmaking refers to the iron ore and coke, oxygen travel digested carbon and hydrogen and other fuels and fluxes (theoretically speaking, iron can also be smelted by mixing metals and ores with stronger metal activity than iron at high temperatures) into the blast furnace for smelting, removing impurities to obtain metallic iron (pig iron).

Accident prevention

1. Gas poisoning accidents in ironmaking plants are the most serious, mostly occurring in front of furnaces and during maintenance operations. The main measures to prevent gas poisoning are to improve the integrity of the equipment and minimize gas leakage.

2. Install gas alarms in places prone to gas leakage.

3. When carrying out gas operations, gas operators wear portable gas alarms and assign special personnel to supervise them.

4. Scalding accidents are also prone to occur in front of the furnace, and the main preventive measure is to improve the level of equipment. Operators should wear protective clothing, and vehicle injuries and machine injuries are also prone to occur in raw material yards and furnaces.

5. Bituminous coal dust preparation and injection system, when the volatile content of bituminous coal exceeds 10%, dust accidents can occur. In order to prevent dust, the main measures are taken to control the temperature of the coal mill, control the oxygen content of the air in the coal mill and the powder collector, and China mostly uses the method of injection mixed coal to reduce the content of volatile matter.

Most of modern ironmaking uses blast furnace ironmaking, and some adopt direct reduction ironmaking method and electric furnace cavity smelting simple iron method. The details are as follows:

1. Blast furnace ironmaking is to reduce iron ore in the blast furnace, melt and smelt into pig iron, this method is easy to operate, low energy consumption, low cost, and can be produced in large quantities. Pig iron is mostly used as a raw material for steelmaking, except for some of the castings. Due to the increasing shortage of high-quality coke coal suitable for blast furnace smelting, non-blast furnace ironmaking methods that use other energy sources instead of coke have emerged one after another.

2. The direct reduction ironmaking method is to reduce the ore in a solid state with a gas body or a solid reducing agent, and at a lower melting temperature than the ore melting, it is smelted into solid or semi-molten sponge iron, metallized pellets or granular iron containing a small amount of impurity elements, which are used as raw materials for steelmaking;

3. In the electric furnace ironmaking method, the reduction electric furnace without furnace body is mostly used, and the coke with poor strength can be used as the reducing agent. The electric heating of the electric digging and balance furnace ironmaking replaces part of the coke, and low-grade coke can be used, but the power consumption is large, and it can only be used under the conditions of sufficient electricity and low electricity price.

"How Steel Is Made" tells the story of Paul Kochagin's journey from an ignorant teenager to a Bolshevik fighter loyal to the revolution, to a blind but strong and unyielding creator**, and a strong piece of steel (referring to his spirit).

How Steel is Made" is an autobiographical **, which praises the spirit of being strong and unyielding in the face of desperate fate and challenging fate, whipping those capitalists who can only be powerful and the ugliness of capitalist society, and showing the spirit of resistance of the proletariat to the oppressed fate at that time represented by the author. It tells the story of Paul Kochakin's transformation from an ignorant teenager to a Bolshevik fighter loyal to the revolution, to a blind but strong and unyielding creator**, and a strong piece of steel (referring to his spirit).

**All descriptions revolve around the growth of the protagonist, and the structure is compact and natural. When portraying the character of the protagonist, he shows his excellent qualities from different angles. By describing Paul's attitude towards prison, war, work, friendship, love, illness, and frustration, as well as how he treats major issues such as revolution and the individual, public and private, life and death, the image of Paul's iron warrior is portrayed as extraordinarily full and vibrant.

How Steel is Made" is written by the former Soviet writer Nikolai Ostrovsky, ** through the growth path of Paul Kochagin, telling people: Only when a person defeats the enemy and defeats himself in the hardships and hardships of the revolution, and only when he links his pursuit with the growth of the motherland and the interests of the people, can he create miracles, grow into a steel warrior, and become steel. The fact that revolutionaries are tempered into steel in the struggle is an important theme of the revolutionary.

Background Analysis: At the age of 22, Ostrovsky was completely paralyzed, bedridden, and blind. It was at this difficult time in his life that Ostrovsky decided to show the times and personal experiences of the time through literature, and he began to conceive "How Steel is Made".

This book was written by him in three years on the sickbed, and the story of Xiao Qiaochun is based on his personal experience. <