Why Dolomite is used in blast furnace?

Why Dolomite is used in blast furnace?

High silica (SiO2) content in the dolomite used for sintering purpose is preferred since SiO2 counter the effect of alumina (Al2O3) in the blast furnace. The second major use of dolomite is in steelmaking. In steelmaking dolomite is used both as a fluxing material and also as a refractory material.

Why is limestone added to the blast furnace along with coke and haematite?

The coke is a source of carbon monoxide which will reduce the iron oxide in the ore to iron and the carbon monoxide oxidizes to carbon dioxide. The limestone acts as a flux to remove other impurities and help the iron physically separate from the rest of the burden.

Why is limestone good for use?

Limestone has numerous uses: as a building material, an essential component of concrete (Portland cement), as aggregate for the base of roads, as white pigment or filler in products such as toothpaste or paints, as a chemical feedstock for the production of lime, as a soil conditioner, and as a popular decorative …

What is the role of lime limestone in steel making?

The largest use of lime is in steel manufacturing, where it serves as a flux to remove impurities (silica, phosphorus, and sulfur). Lime is used in basic oxygen furnaces and electric arc furnaces as well as in secondary refining. Lime is also essential to the production of non-ferrous metals.

What is difference between limestone and dolomite?

What is the difference between Limestone and Dolomite? Limestone is a calcium carbonate mineral whereas dolomite is made of calcium magnesium carbonate. Sand, clay and silt are commonly found in limestone as impurities but not quite common in dolomite.

What fuel is used in blast furnace?

In a blast furnace, fuel (coke), ores, and flux (limestone) are continuously supplied through the top of the furnace, while a hot blast of air (sometimes with oxygen enrichment) is blown into the lower section of the furnace through a series of pipes called tuyeres, so that the chemical reactions take place throughout …

Why is iron converted into 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. Flux (limestone) acts as the chemical cleaning agent, absorbing the iron impurities and leaving behind molten steel.

How is limestone used in extraction?

Limestone is extracted from the rock either by blasting or mechanical excavation depending on the hardness of the rock. rough crushing. After crushing the stone is sorted into different fractions by screening, after which it goes to be processed further. In the grinding process the limestone is ground to a fine powder.

Is limestone harmful to humans?

In its natural bulk state, limestone is not a known health hazard. Limestone may be subjected to various natural or mechanical forces that produce small particles (dust) which may contain respirable crystalline silica (particles less than 10 micrometers in aerodynamic diameter).

Is it safe to eat limestone?

“Slaked lime is also known as calcium hydroxide and limestone is known as calcium carbonate; and calcium is very important for the body. But that doesn’t mean you just directly eat calcium carbonate or lime. This could be harmful for health, and could even cause fatal diseases in some cases.”

Can steel be made without limestone?

The steel industry cannot be conceived without the use of lime, ever-present during the whole steel-making process. And all with a specific goal, that of transforming iron ore into steel and other ferrous products.

Why is lime added to steel?

Steel Products Lime is used to neutralize the acid-based waste pickle liquor in which iron salts are also precipitated. After pickling, steel products are often given a lime bath to neutralize the last traces of the pickling acid adhering to the metal.

What is the chemistry of the blast furnace?

Chemistry of the blast furnace ( continued ). Limestone is calcium carbonate ( Ca CO 3) and it is added. to the blast furnace to remove the impurities in the iron ore. Calcium carbonate is decomposed by heat in the furnace.

What are some of the uses of limestone?

This is mainly used for large-scale agriculture. Quicklime and slaked lime can also be used for this purpose, as well as neutralising acidity in water sources such as lakes. Limestone is also used to remove impurities from the blast furnace when making iron. The impurities are mostly silicon dioxide (also known as sand).

Why is Coke added in the blast furnace during the?

Coke is dumped into a blast furnace, together with iron ore Fe2O3 and ~120kg/t of limestone and dolomite as flux (flux to form slag, containing the impurities, SiO2, CaO, MgO, Al2O3, S), and hot air is blown in to burn the coke to produce heat and to produce CO and CO2.

Why does iron have to be extracted from the blast furnace?

The blast furnace is a huge, Why does Iron have to be ext Iron can be extracted byThe limestone from 2, reacts with the sand to form slag (calcium silicate): CaO(s) + SiO(s) à CaSiO3(l). Both the slag and iron are drained from the bottom of the furnace. The slag is mainly used to build roads.