Green Steel | SMaRT@UNSW

Background

Professor Veena's breakthrough Polymer Injection Technology, or ‘Green Steel’, is a process that leverages high temperature reactions in electric arc furnace (EAF) steelmaking to transform waste tyres and plastics in the production of high‐quality steel. By focussing on the evolution of carbon properties at high‐temperature conditions, Veena completely overturned how the properties of carbon‐bearing materials are understood, bridging the gap between both pure and applied research, as well as between research and application.

The operating efficiency of EAF‐steelmaking (responsible for 40% of global production) is largely dictated by carbon/slag reactions, associated gas evolution and slag forming. In Veena’s world‐first patented Polymer Injection Technology process, a mixture of coke and recycled polymers have been shown to produce a more stable foamy slag compared to coke only – greatly improving furnace energy efficiency, and yield while reducing raw material cost (without detriment to furnace functioning or the finished product).

Polymer Injection Technology’s ‘green steel’ is in commercial production around the world – having been installed and commercially operated in EAF‐steelmaking processes in two domestic and five international sites (in five different countries), resulting in overall cheaper production costs. Furthermore, Polymer Injection Technology’s green steel has been named as an ‘Innovation that could change the way we manufacture’ by the US Society for Manufacturing Engineers.

The commercialisation and ongoing sub‐licensing of ‘green steel’, in Australia and overseas, has demonstrated the many benefits of considering the composition and behaviour of waste streams at their molecular level. Veena has subsequently opened up numerous new pathways for the transformation of complex waste streams into practical, commercially viable ‘green materials’ for production.

Videos

Research Papers

Select journal articles – Green Steel

Sahajwalla VH; Zaharia M; Kongkarat S; Khanna R; Rahman MM; Saha-Chaudhury NM; O Kane P; Dicker J; Skidmore C; Knights D, 2012, 'Recycling end-of-life polymers in an electric arc furnace steelmaking process: Fundamentals of polymer reactions with slag and metal', Energy and Fuels, vol. 26, pp. 58 - 66, http://dx.doi.org/10.1021/ef201175t

Sahajwalla VH; Zaharia M; Kongkarat S; Khanna R; Saha-Chaudhury NM; O Kane P, 2010, 'Recycling Plastics as a Resource for Electric Arc Furnace (EAF) Steelmaking: Combustion and Structural Transformations of Metallurgical Coke and Plastic Blends', Energy and Fuels, vol. 24, pp. 379 - 391, http://dx.doi.org/10.1021/ef900875r

Zaharia M; Sahajwalla VH; Saha-Chaudhury NM; O Kane P; Fontana A; Skidmore C; Knights D, 2013, 'Recycling of rubber tyres in electric arc furnace steelmaking: Carbon/slag reactions of coke/rubber blends', High Temperature Materials and Processes, vol. 31, pp. 593 - 602, http://dx.doi.org/10.1515/htmp-2012-0096

Dankwah JR; Koshy P; Sahajwalla V, 2014, 'Reduction of FeO in EAF steelmaking slag by blends of metallurgical coke and end-of-life polyethylene terephthalate', Ironmaking & Steelmaking, vol. 41, pp. 401 - 409, http://dx.doi.org/10.1179/1743281213Y.0000000125

Dankwah J; Koshy P; O''kane P; Sahajwalla VH, 2012, 'Reduction of FeO in EAF Steelmaking Slag by Blends of Metallurgical Coke and End-of-Life Tyre', Steel Research International, vol. 83, pp. 766 - 774, http://dx.doi.org/10.1002/srin.201200019

Dankwah JR; Koshy P; Saha-Chaudhury NM; O Kane P; Skidmore C; Knights D; Sahajwalla VH, 2011, 'Reduction of FeO in EAF steelmaking slag by metallurgical coke and waste plastics blends', ISIJ International, vol. 51, pp. 498 - 507, http://dx.doi.org/10.2355/isijinternational.51.498

Kongkarat S; Khanna R; Koshy P; O Kane P; Sahajwalla VH, 2011, 'Use of waste bakelite as a raw material resource for recarburization in steelmaking processes', Steel Research International, vol. 82, pp. 1228 - 1239, http://dx.doi.org/10.1002/srin.201100104

Khanna R; Sahajwalla VH; Simento N; Seetharaman S, 2010, 'Atomistic Monte Carlo simulations on the influence of sulphur during high-temperature decarburization of molten iron–carbon alloys', ACTA Materialia, vol. 58, pp. 2235 - 2236, http://dx.doi.org/10.1016/j.actamat.2009.12.010

Zaharia M; Sahajwalla VH; Khanna R; Koshy P; O Kane P, 2009, 'Carbon/Slag Interactions between Coke/Rubber Blends and EAF Slag at 1 550 degrees C', ISIJ International, vol. 49, pp. 1513 - 1521, http://dx.doi.org/10.2355/isijinternational.49.1513

Latest news

Read the latest news from the Centre for Sustainable Materials Research and Technology

Read nowchevron_right

How and why 'Green Steel' became one of Professor Veena Sahajwalla and the SMaRT Centre's best known science and technology innovations.

Overview

The concept of green manufacturing is something that we’ve developed at the SMaRT Centre at UNSW Australia. The whole idea is to think about materials being produced by using waste and end‐of‐life products as raw materials and the concept of green manufacturing as value-adding.

Originally in partnership with OneSteel, the SMaRT Centre developed a process to make green alloys, using end‐of‐life rubber tyres and waste plastic as an alternative to coking coal. Now working with industry partner Molycop, many millions of passenger vehicle tyres have been diverted from landfill in Australia, and the technology has now been commercialised here and overseas in countries including South Korea, Thailand, the UK and Norway. We have shown that the technology of polymer injection into steel making is successful on a commercial scale and that has huge beneficial outcomes for the manufacturing industry as a whole, while at the same time demonstrating the successful translation of research into industry.

At the SMaRT Centre, we take a holistic approach to manufacturing. Our aim is to take our research which is making real-world impact and to disseminate those ‘green social technologies’ to enhance sustainable economic growth – particularly in regional areas of Australia and developing nations internationally. When we define social or green products it’s coming out of the engineering and scientific principles.

Green Steel 2.0+ - next generation technology

We want to make products using waste that add value to the world and at the same time are safe and sustainable.

The SMaRT Centre is now carrying out new, next generation research into the technology by using waste bio-resources like coffee grounds, plastics and rubbers and their application in steel making.

This includes not just using more wastes with the aim of one day replacing the need for coke and coal in electric arc furnace (EAF) steel making, but using waste resources as a source of the vital steel making ingredient of hydrogen for an overall more efficient process requiring less energy.

Here is a March 2022 announcement in relation to three scientific papers revealing new Green Steel next gen breakthroughs.

Here is an October 2021 announcement in relation to new Green Steel next gen research and development work.

Here is 'Story 1' from February 2022 on new Green Steel next gen research and development work by Create Magazine.

Here is 'Story 2' from February 2022 on new Green Steel next gen research and development work by Create Magazine.

Latest Green Steel posts on this website

The below content tiles reference key highlights along the Green Steel journey.

Highlights

Media stories on the Green Steel

DEVEX story 2017

The Australian Magazine story 2019

The Australian Magazine story 2020

Green steel technology wins prestigious award

UNSW Sydney’s Sustainable Materials Research and Technology (SMaRT) Centre has won a prestigious award for its ground-breaking recycling research in collaboration with industry partners. The SMaRT Centre, led by founder Professor Veena Sahajwalla, was recognised for the invention of its ‘Green Steel’ technology in collaboration originally with One Steel and then with long-standing Newcastle-based steel maker MolyCop which is taking the technology across its global operations. More information

In steel, the innovation economy is already here

In this article, Professor Veena Sahajwalla explains the road to achieving the green steel breakthrough, other steel related research and how high-temperature reactions can be leveraged to revolutionise recycling science to reduce costs for today’s businesses and to create entirely new businesses and jobs while delivering environmental benefits. More information

‘Green steel’ technology saves two million tyres from landfill

‘Green steel’ technology invented at UNSW has achieved a major milestone, with its use in Australia preventing more than two million waste rubber tyres from ending up in landfill. The discarded tyres – which would reach as high as the International Space Station if stacked one on top of each other – were used by OneSteel, an Arrium company, to manufacture steel in its Sydney and Melbourne facilities. More information

First Lady of Green Steel Manufacturing

In this feature story by Waste Management Review, Professor Veena talks about how she was able to commercialise her Green Steel technology and gives an overview of her impressive academic career. More information

Recycling science and Green Steel

CPA's In the Black publication documents the achievements of Professor Veena, from Green Steel to her latest developments in microrecylcing science. In 2003, Sahajwalla invented polymer injection technology (PIT), known as green steel. An environmentally friendly and cost-effective process for using recycled rubber tyres, the technology has been licensed to steel makers globally, and Sahajwalla and her team are working with Newcastle-based steelmaker MolyCop, which plans to implement the technology across its global operations. More information