Steel ‘waste’ sent to BRO to build border road in Arunachal

Subject : Science

Context-

Science and Technology Minister Dr Jitendra Singh flagged off the dispatch of a 1,600-metric tonne processed steel slag railway rack from Tata Steel’s Jamshedpur plant to the Border Road Organisation’s (BRO) ‘Project Arunank’ in Itanagar, Arunachal Pradesh.

About Project Arunank-

Project Arunank is responsible for the construction and maintenance of approximately 1113 Kms of roads in Arunachal Pradesh and Assam.
The project was carved out from one of the oldest projects of BRO Project Vartak.
Project Arunank is named after the state of Arunachal Pradesh.
The project is being carried out by CSIR-CRRI along with Tata Steel and BRO.
In this project the processed steel slag aggregate — a by-product of steel manufacturing — will be used in the construction of steel slag road stretches in strategic areas.
This project is a perfect example of ‘waste to wealth’.

Steel production in India-

India is currently the world’s second-largest producer of crude steel, producing over 118 million tonnes of crude steel.
Of this, around 20% of steel slag is generated as solid waste and its disposal is a big challenge to steel industries.
India is the 2nd largest consumer of finished steel in 2021 (106.23 MT), preceded by China.
The National Steel Policy, 2017 envisage 300 million tonnes of production capacity by 2030-31.
The per capita consumption of steel has increased from 57.6 kgs to 74.1 kgs during the last five years.
Major steel-producing states in India- Odisha, Chhattishgarh, Jharkhand and Karnataka.

Steel slag-

It is a by-product of steelmaking and is produced during the separation of the molten steel from impurities in steel-making furnaces.
It comes out during the manufacturing of steel through three processes, namely basic oxygen furnace (BOF) route, electric arc furnace (EAF) and induction furnace (IF).
The slag occurs as a molten liquid melt and is a complex solution of silicates and oxides that solidifies upon cooling.
There are several different types of steel slag produced during the steel-making process namely- furnace or tap slag, raker slag, synthetic or ladle slags, and pit or cleanout slag.

Uses of steel slag-

It can be used as a granular base or as an aggregate material in construction applications
Slag is used in asphalt paving on Highways and road construction
Carbon dioxide sequestration using steel slag
Recently a six-lane highway in Surat made of steel slag — a first in India is being inaugurated.

Benefits of using steel slag in road construction-

The use of such material in road construction increases its durability.
It helps in reducing the cost of construction as slag-based materials have better properties than natural aggregates.
The use of steel slag in road construction will also address the shortage of natural aggregates in the country.