What is the purpose of the new steelmaking process at Glenbrook Steelworks in New Zealand?

The new Electric Arc Furnace (EAF) will reduce greenhouse gas (GHG) emissions and modernise New Zealand Steel’s operations, replacing part of the existing steelmaking process with a lower-emission, scrap-fed alternative.

How will the new steelmaking process at Glenbrook Steelworks differ from the current steelmaking method?

The Electric Arc Furnace (EAF) will use 50% less iron and increase the use of local scrap steel, removing high-emission units like the oxygen steelmaking furnace (KOBM), and half the kilns and melters. It will also be powered by renewable electricity instead of coal.

How does New Zealand Steel’s Electric Arc Furnace project contribute to BlueScope’s 2030 emissions target?

The EAF will help BlueScope achieve its global target to reduce GHG emissions intensity by 12% by 2030. The Company has already met this target in FY2024.

Why is Glenbrook Steelworks strategically important?

Glenbrook is New Zealand’s only fully integrated steel producer, manufacturing 670,000 tonnes of steel annually, and employing 1,500 people in New Zealand and the Pacific Islands.

How does the Electric Arc Furnace project support a circular economy in New Zealand?

By reducing scrap exports by 50% and processing more scrap domestically, New Zealand Steel moves toward self-sufficiency in steelmaking and lowers GHG emissions from transportation.

15 December 2024

Supporting
New Zealand’s climate transition

In 2023, we announced that New Zealand Steel is to build an electric arc furnace (EAF) to secure the future of lower GHG emission steelmaking at Glenbrook Steelworks. To be co-funded by the New Zealand Government, the new EAF is projected to start commissioning by the end of 2025.

This case study gives a snapshot of the positive effect the EAF will have on New Zealand's carbon footprint, and BlueScope making progress toward its goal to achieve net zero greenhouse gas emissions by 2050, a goal that is highly dependent on several enablers. For more information on our net zero goal and enablers, visit our Steelmaking page.

Our focus on reducing New Zealand’s carbon footprint

New Zealand Steel’s new EAF will replace the existing Glenbrook steelmaking process, whilst retaining approximately 50 per cent of the ironmaking capacity at the plant. The EAF will be fed by a combination of large amounts of scrap and 50 per cent less iron than used today.

The site's Scope 1 and 2 greenhouse gas emissions are expected to reduce by up to 55 per cent, and New Zealand's overall country emissions by one per cent. According to common practice, we characterise steelmaking GHG emissions in accordance with the GHG Protocol: direct emissions from our operations are referred to as Scope 1; and indirect emissions from the energy we buy are referred to as Scope 2.

Our commitment to the EAF project is due to local supply of domestic scrap steel and electricity from a large renewable grid, and co-investment from the New Zealand Government. With these enablers in place, an EAF is the right solution for New Zealand Steel.

BlueScope already operates low emission intensive EAF steelmaking technology at its mini-mill in North America, where scrap - the key raw material - is processed through an EAF (referred to as 'secondary' steelmaking). Our integrated steelworks in New Zealand and Australia use higher emission intensive technologies referred to as 'primary' steelmaking, because they both first produce iron which is then used to produce steel. Go to our Steelmaking page for more on our three steelworks and how each is working to enable lower emission steelmaking.

Learn more about our steelmaking

Glenbrook is vitally important to the region

New Zealand Steel is the only fully integrated steel producer in New Zealand, using locally sourced ironsand to manufacture up to 670,000 tonnes of steel slab and billet a year at the Glenbrook Steelworks, located south of Auckland.
In addition to New Zealand Steel, the combined New Zealand & Pacific Islands (NZPI) business comprises Waikato North Head ironsand mine, Pacific Steel and the Pacific Islands businesses located in Fiji, New Caledonia and Vanuatu.
NZPI, with a workforce of 1,500 people, produces a range of flat and long steel finished products for the New Zealand and Pacific regional construction, manufacturing, infrastructure, packaging and agriculture segments.

Our transformative solution to lower carbon emissions

Our current process

New Zealand Steel’s integrated steel plant at the Glenbrook Steelworks uses direct reduced ironmaking (DRI) and basic oxygen furnace (BOF) steelmaking technologies.

Ironmaking to reduce the iron from its raw material, ironsand, is done in a kiln and melter process. The iron is then converted into steel in an oxygen steelmaking vessel (KOBM). Coal is the reductant in the ironmaking process to produce the iron. This process was designed by New Zealand Steel to suit the specific qualities of ironsand as a raw material.

Glenbrook’s unique ironmaking processes use local ironsand, along with coal and limestone, which is heated and dried in one of four multi-hearth furnaces. It is then fed into one of four reduction kilns, where hot gases convert 80 per cent of it to a DRI metallic iron product, which then passes through melters to produce molten iron ready for steelmaking via oxygen steelmaking.

An oxygen steelmaking furnace (KOBM) converts the molten iron from the melters, with added scrap, into steel. To refine further, ferro-alloys are added to bring the steel composition up to its required specification, and the molten steel is then transferred to one of two continuous casters, for casting into slabs or billets. 

Our current process

New Zealand Steel’s integrated steel plant at the Glenbrook Steelworks uses direct reduced ironmaking (DRI) and basic oxygen furnace (BOF) steelmaking technologies.

A new EAF - the right decision

New Zealand Steel is well placed with access to electricity generated from renewable sources and opportunities to use local scrap that is currently exported:

EAFs rely on large amounts of scrap steel and high quantities of electricity to produce steel.
EAFs usually produce lower carbon GHG emissions than traditional integrated 'primary' steelmaking operations, because the higher scrap volumes used in the EAF process displace quantities of iron required, which is the most emissions intensive part of the process. It’s important to note that scrap steel only exists because the steel was first created in a primary steelmaking process.
Emissions reductions are further enhanced when electricity is powered by renewable energy.

More emissions intensive process units will be removed:

The KOBM steelmaking unit will be completely replaced.
Half of the existing ironmaking units will no longer be required (two kilns and one melter).

Visualising the transfomation in our process diagram and in pictures

A low emission intensive EAF at Glenbrook leverages a plentiful supply of steel scrap feed, taking opportunities to use scrap currently being exported and to increase scrap feed to the EAF over time.

The EAF will also process iron from Glenbrook’s existing ironmaking process which sources ironsand from the company’s local Waikato North Head ironsand mine. After commissioning, the EAF will use 50 per cent less iron feed than today.

Along with coal and limestone, the ironsand is currently processed using four multi-hearth furnaces, four reduction kilns, and two melters to convert it into molten iron, ready for steelmaking. The EAF will remove key higher emission process units - two kilns and one melter.

An oxygen steelmaking furnace (KOBM) currently converts the molten iron from the melters, together with added scrap, into steel - which is then refined further and transferred to a caster for turning into slabs or billets. The EAF will remove the high emission intensive KOBM unit.

Slab or billet steel exits the caster for final processing and finishing as steel coil, housed ready for distribution.

Up to 55% reduction in NZS greenhouse gas emissions

New Zealand Steel's emissions more than halved, contributing to BlueScope’s net zero goal by 2050.

Approximately 50% less coal used at Glenbrook’s plant

Coal usage halved, with approximately 50% of ironmaking being displaced by the EAF process

NZS CO₂e reduced to 1.6 or better, below world average of 1.9

Raw steel emissions intensity (tonnes CO₂e per tonne raw steel produced) nearly halved, reducing further with increasing scrap input.

New Zealand scrap export being reduced by approximately 50%

Moving to maximise scrap usage in NZ rather than exporting, which incurs cost and carbon miles.

Up to 1 million tonne reduction off Glenbrook’s carbon footprint

New Zealand’s footprint shrinks by 1%, equivalent to taking at least 300,000 cars off the road permanently.

The electrification of steelmaking

Steelmaking powered by electricity sourced from New Zealand’s predominantly renewable grid.

Sustainability at BlueScope

At BlueScope, sustainability means working for our success in the right way that benefits our people, customers, communities, supply chains and the environment. Learn more about our strategic priorities below:

Safe, thriving people and engaged communities

Putting people at the heart of what we do; putting safety first and valuing dignity and respect in our workplaces, supply chains and local communities.

Action on climate and environment

Taking action on critical challenges for the planet and society; through technology and how we work.

Responsible products and supply chains

Understanding industry impacts, trends and customer needs, and collaborating to create responsible, future-ready products and solutions.

Enduring business strength and growth

Operating and transforming our business for long-term success with strong governance and capital discipline.