Publisher Summary. Metallurgical coke, along with iron ore and limestone, is layered into a blast furnace to convert the iron ore to metallic iron. Coke, which is mostly carbon, reacts with the blast air to produce carbon monoxide, which, in turn, reacts with the iron oxide to produce carbon dioxide and metallic iron.
Why is limestone added to the blast furnace along with coke and haematite?
Iron is extracted from its ore, haematite, in a blast furnace. The ore is fed into the top of the furnace along with coke and limestone. … The limestone decomposes in the hot furnace, forming calcium oxide. This reacts with the sandy impurities (silicon dioxide) to form a slag…..
Why is limestone added to the blast furnace during iron extraction?
Limestone is also used to remove impurities from the blast furnace when making iron. The impurities are mostly silicon dioxide (also known as sand). The calcium carbonate in the limestone reacts with the silicon dioxide to form calcium silicate (also known as slag).
What are the 4 raw materials needed in the extraction of iron?
The raw materials used to produce pig iron in a blast furnace are iron ore, coke, sinter, and limestone. Iron ores are mainly iron oxides and include magnetite, hematite, limonite, and many other rocks.
What raw materials are added to the blast furnace?
The three main raw materials used to make pig iron (which is the raw material needed to make steel) for primary steel production in a blast furnace are the processed iron ore, coke (residue left after heating coal in the absence of air, generally containing up to 90% carbon) and limestone (CaCO3) or burnt lime (CaO), …
Which reaction is used to keep the furnace hot?
The hot air blast to the furnace burns the coke and maintains the very high temperatures that are needed to reduce the ore to iron. The reaction between air and the fuel generates carbon monoxide.
Why is iron converted into steel?
The combustion of iron ore with other materials in the blast furnace produces molten pig iron, which is then converted to steel. … Blowing oxygen forces impurities (oxides, silicates, phosphates, etc.) to react with flux to form slag or escape through the top of the furnace as fumes.
Why Dolomite is used in blast furnace?
The use of dolomite in blast furnaces
Dolomite is used in the production of iron because the amount of MgO as a slag can be prefixed by using a different amount of dolomite. During the filtration of iron by blast furnace method dolomite is either used in sintering method or directly inserted into the furnace.
Which oxide is reduced in blast furnace?
The blast furnace
Reactions in which oxygen is removed are called reduction reactions. In this reaction, the iron(III) oxide is reduced to iron, and the carbon is oxidised to carbon dioxide.
What is the purpose of limestone in a blast furnace?
Limestone is also used to remove impurities from the blast furnace when making iron. The impurities are mostly silicon dioxide (also known as sand). The calcium carbonate in the limestone reacts with the silicon dioxide to form calcium silicate (also known as slag).
How does the blast furnace work?
The blast furnace is a huge, steel stack lined with refractory brick, where iron ore, coke and limestone are dumped into the top, and preheated air is blown into the bottom. … The hot air that was blown into the bottom of the furnace ascends to the top in 6 to 8 seconds after going through numerous chemical reactions.
Which reaction increases the temperature in the blast furnace to over 1500?
The reaction between oxygen and carbon is exothermic and is responsible for increasing the temperature of the blast furnace.
Which is the better fuel coal and coke?
Coke is a better fuel than coal because; -Coke produces more heat on burning than coal. -Coke has a higher calorific value than coal. When equal masses of coke and coal are burnt, coke produces more heat.
What is M40 in coke?
The resistance, in Micum drum, is an international standardized method, being the most used one, indices obtained in the test are: M40= mechanical resistance M10 = abrasion For a high quality coke these indices must have values between M40= 80 ÷ 85% and M10 = 5 ÷ 7%.
How steel is made in blast furnace?
To make steel, iron ore is first mined from the ground. It is then smelted in blast furnaces where the impurities are removed and carbon is added. … About halfway down, limestone begins to react with impurities in the ore and the coke to form a slag. Ash from the coke is absorbed by the slag.
What fuel is used in blast furnace?
The iron blast furnace uses carbon as a fuel to meet the energy requirements of the process as well as a reducing agent for smelting the iron ore to pig iron. The most widespread form of carbon used for this purpose is metallurgical coke.
What are the uses of dolomite?
Uses. Dolomite is used as an ornamental stone, a concrete aggregate, and a source of magnesium oxide, as well as in the Pidgeon process for the production of magnesium.
What is difference between limestone and dolomite?
Limestone is made of calcium carbonate. Dolomite is made of calcium magnesium carbonate.
What are uses of steel?
Steel is one of the most widely used materials, with applications in construction, engineering, agriculture and the manufacture of cars. With more than 50% of all products in the world coming from steel and steel fabrication processes, it is estimated that there are over 20 billion tonnes of steel currently in use!
How are impurities removed from steel?
Through the use of an air and chlorine mixture (10:1), zinc is selectively removed from steel at 800°C in the laboratory. The reaction products characterized by various analytical techniques confirm the thermodynamic analysis. This process offers an attractive solution to obtain clean steel scrap and useful chemicals.
How much iron ore is used in steel?
It takes around 1.6 tons of iron ore to produce one ton of steel.
What is the easiest metal to extract?
Many metals can be reduced and extracted in a school laboratory. The easiest are iron, copper and lead.
What heats a blast furnace?
At the bottom of the blast furnace, the hot air of 1200℃ heats the materials and fuels. The hot air with a force of 4.0bar triggers such a force that the materials fly up in the air. Because of the heat, coke chemically dissolves the raw materials.
Who Discovered blast furnace?
Hot blast was patented by James Beaumont Neilson at Wilsontown Ironworks in Scotland in 1828. Within a few years of the introduction, hot blast was developed to the point where fuel consumption was cut by one-third using coke or two-thirds using coal, while furnace capacity was also significantly increased.