Coffee grounds part of green-steel breakthrough

Molycop, a supplier of mining consumables, has shown through industrial trials of Green Steel Polymer Injection Technology (PIT) that various wastes can be used more sustainable to make steel in electric arc furnaces.

Wastes including plastic and coffee grounds now join waste rubber tyres as alternative sources of coke and coal as previously vital ingredients as carbon sources for steel making, and can provide the element hydrogen which vastly improves the efficiency and energy required for the manufacturing process.

“Steelmakers have to meet the demands of quality requirements,” said UNSW SMaRT Centre Director, Professor Veena Sahajwalla. “The metal that gets produced doesn’t have any memory of whether the parent material that went in was coal or coffee. It gives you the kind of productivity requirements that any commercial operator will want.”

Steel made via this process, according to Sahajwalla, does the job at a comparable level and expects equivalent performance. She added it would be ideal if coke could be completely eliminated from the process.

“If you have a combination of materials, you get a better outcome because you’re able to finetune and customise green steel and take the kinds of materials that do the best job,” Sahajwalla said. ‘’This is not a waste; it’s a really useful resource. It’s going to be an interesting shift towards valuing our waste resources and thinking about those inno­vative supply chains where recycling and manufacturing can be coupled together.”