Reducing the carbon intensity of metals production

September 17th, 2019

Dr Mark Cookseyby Mark Cooksey

It is well known that metal production is highly carbon-intensive, and the social, economic and environmental pressure on operations to reduce carbon intensity has grown extensively over recent years.

As a first step, renewable electricity can be used to reduce the carbon intensity of electricity use. However, carbon is directly used in many metal production processes, and it is much more difficult to reduce the CO2 emissions associated with the consumption of this carbon.

While many operators recognise the need to reduce the carbon intensity of their processes, the feasibility and value of doing so remain unclear for many; achieving major reductions is difficult for operations to accomplish on their own.

But with the right research and development, reducing carbon intensity through effective alternatives can be achieved, enabling you to maintain operations throughout industry, legal, and environmental changes.

Low raw material costs don’t reflect the true cost of carbon

Despite being cost-effective in the immediate term, the use of fossil carbon may increasingly come back to create negative outcomes for your operation:

  • High costs

In the future, fossil carbon may well not be the cheapest processing option. While implementation is variable among different countries, it is plausible that carbon pricing will become more common, driving up the cost of fossil carbon.

  • High financing costs

There is evidence that banks are considering carbon intensity in their investment decisions. For example, the owners of Gold Coast Airport will pay lower interest rates on a $370 million expansion if it meets annual carbon reduction targets.

  • Reduced social licence to operate

As social awareness about the potential impacts of CO2 emissions grows, so does the pressure faced by operations from communities and shareholders to reduce their impact. For example, a shareholder resolution was recently filed with BHP in an attempt to suspend its membership of some industry groups.

Some operations have been successful in marginally reducing their carbon intensity. But without significant research and changes to processes and equipment, there is little chance of significantly reducing emissions.

Assessing your ability to reduce carbon intensity through process changes

Despite the difficulties, there are ways that you can work towards reducing carbon intensity.

Assessment and investigation of your current practices, and your ability to change these practices, is the first step to achieving reduced carbon emissions across your operation.

  1. Rigorously assess uses of carbon in your operations, including performance specifications

Carbon is used in many different applications in metal production, and the property requirements are varied. Understanding these applications and properties in detail can help you identify opportunities to reduce carbon intensity with the biggest magnitude and highest likelihood of success.

  1. Investigate whether CO2 can be captured from operations

It may be possible to apply carbon capture and storage (CCS) to your processes. This option may require less process changes than the more disruptive technologies discussed below. The primary aluminium industry has considered how to apply CCS to its processes.

  1. Investigate alternative, sustainable sources of carbon

Charcoal obtained from pyrolysis of biomass offers an alternative to coal as a reductant. The iron and steel industry originally used charcoal, and this was only replaced with coal in the early 20th century. While the consumption of charcoal will still result in CO2 emissions, the CO2 consumed during the growth of the biomass reduces the net CO2 emissions over the lifecycle. Charcoal is used in some steelmaking in Brazil.

  1. Investigate alternative reductants

Carbon is not the only reductant for metal ores. Hydrogen may be able to be used instead, producing water as by-product instead of CO2. A Swedish consortium is investing heavily in hydrogen steelmaking.

To date, the cost and risk of major process changes, paired with the uncertainty in carbon pricing and regulatory requirements, have dissuaded many operations from pursuing these opportunities.

However, there are major companies who are beginning to invest more heavily to reduce carbon intensity.

For example, BHP has announced they will invest $400m to reduce carbon emissions, including in downstream operations that purchase iron ore, coal and crude oil from BHP.

Stay ahead of the curve by partnering with experts

Changes to the metal production industry and the regulations around carbon emissions are on the way. It has become a situation of not if, but when operations will have to change their processes to reduce carbon intensity.

By investing in solutions now, you give your operation the best chance of remaining both compliant and profitable throughout these industry changes.

CSRIO has deep expertise and facilities specifically relevant to metal production, CO2 capture and sustainable sources of carbon, and broadly in process development. Examples include:

Because of the nature of our organisation, CSIRO also has a unique ability to draw on expertise and abilities from all over the organisation that can specifically help with emission-reduction development (for example, our extensive work to improve hydrogen transport).

Now that you are aware of your options, CSIRO can work with you to test options at scale to determine viability for your operation.

If you’re interested in minimising your reliance on fossil fuels and reducing the carbon intensity of your operation through the development of alternative solutions, we are uniquely positioned to assist you and add value to your project.

Contact the team on +61 3 9545 8865 or email me,, to discuss how our expertise and experience can help you.

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