What is Sponge Iron?

22

Sponge iron is a raw material that is used to make steel and other metals. It can be produced by direct reduction of iron ore or through an electric arc furnace. The process produces less carbon dioxide than blast furnaces.

Iron sponge can also be used to remove the corrosive, bad-smelling hydrogen sulfide found in gas streams. This happens by down-flowing gas through a bed of hydrated iron oxide.

It is a form of iron.

Sponge iron is a metallic product made through the direct reduction of iron ore in the solid state. It is also known as naturally reduced iron (DRI). The process of making sponge iron aims to expel oxygen from the iron ore and increase its quality. Compared to conventional blast furnaces, this method reduces steel production costs and energy usage. It is also environmentally friendly since it does not produce any greenhouse gases.

It is produced by heating the ore to a temperature high enough to burn off carbon but not high enough to melt it. It is then filtered into two size fractions: +3 mm and -3 mm. The latter is used directly, while the former can be rolled into briquettes using molasses and hydrated lime as binders. Mini-steel plants then utilize the briquettes to create steel products.

Sponge iron is a critical raw material for the manufacturing of TMT bars, rebars, and other steel/iron-based items. It is a significant substitute for scrap, which is necessary for the melting of steel in electric arc furnaces and integrated steel plants. It is also a cheaper alternative to traditional iron ore and provides better product quality. Sponge iron has lower impurities, including sulfur and phosphorus, than traditional ore, which helps in achieving higher strength and durability of the final product. It is also a safer and less polluting alternative to conventional iron ore. In 2009, the Delhi non-profit Centre for Science and Environment studied compliance with pollution norms in 204 sponge iron factories. This was the most extensive sample study of its kind in India, covering factories in Jharkhand, Chhattisgarh, Odisha, and West Bengal.

It is a metal.

The iron sponge is an essential raw material for steel manufacturing. It is a product of the direct reduction of iron ore using reducing gas. It contains high levels of iron and low impurities. It can be used as a substitute for scrap in steel-melting furnaces. It is also used in foundries for a variety of cast iron products. It is a good source of iron for use in the chemical industry and can be remelted and used as a coolant in electric arc furnaces.

Sponge iron is produced from natural gas or coal-gasified hematite ore in the form of lumps or pellets by direct reduction with reducing gases. This process removes oxygen from the iron ore, leaving a metal with high iron content and low impurities. It is a more efficient process than blast furnace pig iron but still requires substantial processing to make steel.

Sponge iron factories have mushroomed in iron ore and coal-rich states like Jharkhand, Odisha, Chhattisgarh, and West Bengal. The pollution emitted by these factories has been a significant cause of concern for the local communities. Every morning, people living near sponge iron plants are not able to see the sunrise due to a smoggy blanket of pollutants. The state pollution control boards have issued notices to many of these factories, but they are defying norms with impunity.

It is a fuel.

Sponge iron is a fuel that can produce energy on a large scale. Its use as a substitute for coal has been shown to reduce carbon emissions. It also helps in reducing harmful pollutants, including NOx and SO2. A recent pilot project conducted in Lulea, Sweden, produced the first-ever hydrogen-reduced sponge iron without using fossil fuels. This is the result of a collaboration between steelmaker SSAB, utility company Vattenfall, and iron ore pellet producer LKAB.

The new technology uses fossil-free electricity to generate hydrogen from water by electrolysis, which is then used in place of coal to heat the sponge iron kilns. The pilot plant is a part of the Swedish startup HYBRIT, which has already completed its first production run of fossil-free steel on a small scale. It is hoped that the technology will be able to be replicated in other countries.

Iron Sponge has a low sulfur content and is free from other impurities like copper, zinc, tin, chromium, and molybdenum. It can be directly fed into electric arc furnaces and has the potential to improve power levels. It can also be used as a coolant in the L.D. converter, which can reduce the likelihood of equipment breakdowns. It should be stored in a dry place and must not come into contact with moisture prior to usage. If it does, it can become oxidized and corroded.

It is a raw material.

Sponge iron is a raw material used to produce steel. It is also known as direct reduced iron (DRI). It is produced by directly reducing an iron ore pellet or lump in a solid state using a reducing gas. The reducing gas can be made from natural gas, coal, or hydrogen. The DRI is cheaper than pig iron, and it is less polluting.

The primary raw materials for sponge iron are iron ore and non-coking coal. These are charged into a rotary kiln in the required ratio, along with dolomite, which acts as a desulphurizer. The kiln is heated to 850-1100 deg C for the reduction process to take place. The resulting product is a sponge-like micropic view of Fe2O3. It is then blown off to separate the slag and carbon. Sponge iron is energy-efficient and a good substitute for scrap metal in the EAF and BOF routes of steelmaking.

The Central Pollution Control Board classifies sponge iron as a “red category” industry, which means it requires stricter pollution norms and frequent inspections. However, the country’s sponge iron sector is far from meeting these requirements. A recent study by the Delhi-based Centre for Science and Environment found that 204 sponge iron factories in Jharkhand, Chhattisgarh, Odisha, and West Bengal were flouting pollution standards. The study was based on inspection and night inspection reports from the state pollution control boards. It also included stack monitoring data from these plants.