As foundation industries search for new and innovative ways to decarbonise their operations, companies are finding exciting ways to work together – boosting sustainability and increasing efficiency.
This is the idea behind RECTIFI, a partnership which brings together two of the world’s biggest steel and cement manufacturers – sectors which are responsible for 11%* and 7%** of global emissions, respectively.
RECTIFI – which stands for ‘Reducing Embedded Carbon Through Transformation In Foundation Industries’ – will see the creation of a brand-new supply chain for green steel, utilising leftover material to create a mineral-rich low carbon alternative to clinker, a carbon-intense ingredient used to make cement. The project brings together global leader in sustainable materials EMR, leading steelmaker Tata Steel and cement manufacturer Aggregate Industries with the goal of avoiding almost 5 million tonnes of CO2 from entering the earth’s atmosphere each year.
Another important company involved with the RECTIFI project is industrial waste management firm Darlow Lloyd. The firm has decades of experience with re-using and utilising waste material which would otherwise end up in landfill.
“Our business stretches back to the 1980s when we first won the contract for handling waste going to landfill for the steelworks at Port Talbot. Since then, we have built a reputation for finding new, sustainable uses for waste material that reduces or avoids the use of landfill altogether,” says Owain Lloyd, Director at Darlow Lloyd.
And Owain says his role chimes closely with the aims of the RECTIFI project: “I look after the research and development side of things – handling problematic waste. There’s a lot of sludge and waste when you produce steel and, as a business, we come up with different ways of using it.”
The scale of the material Darlow Lloyd & Sons ltd handles is considerable: “The material we process comes from steel manufacturers across the UK. As a rule of thumb, the production of a tonne of liquid metal using a BOF and BOSP will produce circa 300kg of Blast Furnace Slag which is classed as a by-product and circa 150kg of steel slag which is classed as a waste. Both types of this Slag are used to create sustainable construction materials. This process also produces up to 150kg of various metalliferous sludges and dusts from the process.
“This sludge has been the Achilles’ heel of the industry because, historically, it has ended up in landfill. My team specialises in finding sustainable ways of processing this final part – removing zinc, rare-earth metals, and a number of other useful materials. We tend to focus on the hazardous sludge because – from a business perspective – there’s more of a saving if we reprocess it.”
By far the biggest opportunity, however, is extracting further steel from this by-product of the industry, Owain says:
“Many process wastes that the iron and steel industry discard have a high ferrous content. Every steelworks in the world produces sludge and, while it used to be sent to landfill, it is more cost effective to reuse it back into the process. An iron ore pellet from Australia or South America contains about 63% Fe, the discarded metalliferous sludges and dusts contain circa 40-50% Fe so the percentage of potential new steel that can be extract from this material is not a million miles away from what the industry is used to handling. The difference is that this material is already here in the UK and will help to dramatically reduce the industry’s use of landfill sites.”
There are challenges and Darlow Lloyd works closely with the Environment Agency and other regulators to ensure that these new processes are both safe and sustainable: “Because this waste contains harmful elements, we can’t just take the material and throw it back into the furnace – most steelmakers’ furnaces are not licenced to burn waste and it requires different exemptions.”
Yet using a waste product in a novel way is one way that the steel industry – and other foundation industries – can prepare for the future decarbonised economy in which they must operate after 2050.
“Our business is hands on and practical and we’re accustomed to dealing with the massive tonnage produced by the UK’s biggest and best steelmakers,” says Owain. “As the RECTIFI project develops, we stand ready to create a more efficient, circular steel industry and to produce the state-of-the-art sustainable materials needed for a greener, cleaner cement sector.”
* https://www.globalefficiencyintel.com/new-blog/2021/global-steel-industrys-ghg-emissions
** https://www.chathamhouse.org/sites/default/files/publications/2018-06-13-making-concrete-change-cement-lehne-preston-final.pdf