In the DRI plant, production of sponge iron using a solid reductant involves reducing iron ore (lumps/pellets) with carbonaceous materials like coal or lignite. The reduction is carried out in a rotary kiln (which is inclined and rotates at a predetermined range of speeds) at a stipulated temperature (850°C -1050°C). The inclination and the rotary motion of the kiln ensure that the raw materials move from the feed end to the discharge end of the kiln and during this movement the actual reduction of iron ore to iron takes place. The material discharged from the kiln is taken to a rotary cooler for cooling and the cooled product is separated from the coal char.

In the Electric Arc Furnace operation(SMS plant): Steps involved in arc furnace can be summarized as follow:

1. Charging

2. Melting

3. Refining

4. De-slagging

5. Tapping

1. Charging: The Charge is prepared according to the grades proposed to be made for target chemistry, Sponge iron and other ingredients along with lime in a close requisite ratio is charged in the arc furnace.

2. Melting: Melting is accomplished by injecting energy to the charge materials in the form of electrical energy through three numbers graphite electrodes. Carbon injected inside the furnace reacts with oxygen producing CO, which bubbles through the bath creating foamy slag. the excess CO reacts with oxygen converting to CO2 again generating heat. Oxygen will react with several components present in the bath including silicon; Phosphorus and sulphur. The oxides thus formed will end up in the slag. In arc furnace charged materials get melted at about 1800°C. Once sufficient charge has been melted and enough space has been created, second charge can be taken and the process is repeated. Once the final charge has been melted and is reached at melt stage, Temperature measurement is taken and sample is drawn for determining the amount of oxygen to be blown during refining.

3. Refining: Refining means reduction of undesirable elements in steel like sulphur, Phosphorus etc and also bringing down the carbon to required levels. The Phosphorus and sulphur which cannot be removed from induction furnace's melting, can be easily removed in EAF. Phosphorous is removed in the early stage of refining. Sulphur is removed as sulphides in slag and is better achieved during reducing stage. Aluminium, silicon and manganese reacts with oxygen earlier than carbon to form oxides which goes into the slag. CO, which is produced due to the reaction of carbon with oxygen bubbles through the bath causing the slag to foam and has many beneficial effects. The foaming also helps in bringing down nitrogen and hydrogen levels in steel. At the end of refining stage temperature measurement is done and sample is drawn for analysis.

4.De-Slagging: De-slagging is the process by which the slag layer above the steel is removed from the furnace. This process is important for removing impurities from the melt. The furnace is titled towards the slag door for slag removal. Phosphorus is transferred to the slag, during the early stage of the heating while the temperature is relatively low. The first de-slagging (at the start of refining) removes the substantial portion of the phosphorous (as P2O5), Thus preventing phosphorous reversal to the metal. In a typical refining stage, the furnace may be de-slagged several times.

5.Tapping: After reaching the temperature and composition aimed for, the tap hole is opened and metal is tapped into ladle and sent to continuous casting unit for casting of billets. During the tapping process bulk alloy additions are made based on the bath analysis for the desired steel grade. De-oxidizer may be added to the steel to control the oxygen content prior to the further processing. This is commonly referred to the killing of steel. This is done by aluminum or silicon in the form of ferrosilicon or silicon manganese.

Molted steel from EAF is tapped into a ladle and taken to the continuous casting machine. Liquid steel flow out of the ladleinto the tundish and then into a water-cooled mold. Solidification begins in the mold. The continous Billets coming from the CCM is cut - out according to the length required. The billets thus manufactured are re-heated at a temperature of 1200°C in the re-heating furnace and are rolled into specific sections of finished material in the Rolling Mill Unit.

In case of manufacturing TMT bars, the "Thermex Process" is followed as explained below:

From the finishing stand of the rolling Mill, the Re-Bars are guided through a specially designed proprietary Thermex pipes in which water quenching is done under controlled conditions. The surface temperature of the hot Re-Bars falls drastically from 900°C to around 400°C on account of the intense and uniform cooling, whereas the core temperature remains the same.

At the Cooling Bed, temperature equalising takes place at round 600°C. This makes the surface of the Re-Bar a hardened structure called tempered martensite. The core remains soft and is known as ferite-perlite. This process increases the tensile strength of the material while keeping high ductility and weldability. This whole process is a patented technology from HSE, Germany under the brand name of "Thermex".

The Rolling Mill is one of the most advanced units in India equipped with latest machineries for quality manufacturing. The Quality Control Lab is also equipped with all the necessary equipments for high grade Quality Control.

In the Howrah plant of the company, the Billets produced in its Durgapur unit are rolled into a variety of structural steel products like M.S. Round bars, M.S. Angles, M.S. Joists, M.S. Channels, M.S. Flats Bars and Window Sections.

Being ISO: 18001 certified, the company considers safety and environment prevention an integral part of its responsibilities. Hence, proper care is taken of the Health and Safety of its workers in the plant as mentioned in the company's health and safety policy.

To abide by its Environment Prevention Plan, the company has an ESP setup by Elex AG Switzerland, in its DRI unit. This serves a dual purpose of filtering particles like coal ash and also reducing the amount of suspended particles in the gases emitted out by the plant. The company also maintains lush gardens and landscapes around the plant contributing to the Green Belt Revolution. The company is ISO: 14001 certified and follows the principles of its Environment Management policy in full spirit.

The quality products manufactured in its plant ensure to provide its customers with the 'Best Value for Money', and therefore to loyally abide by its promise to provide them with 'Complete Customer Satisfaction'.

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