Cocoon LoopCem Slag-Based SCM

Cocoon Carbon (Cocooncarbon Ltd) was founded in 2023 and is registered in London, United Kingdom. It develops low-carbon construction materials, turning by-product slag from electric steelmaking into a supplementary cementitious material for cement and concrete producers.

The product is LoopCem, an SCM engineered from electric arc furnace slag that performs comparably to existing SCMs at a 30% weight replacement ratio. A rapid-cooling system integrates into the slag-handling operations of steel mills. The company targets cement and concrete producers and EAF steel plants.

• LoopCem SCM: low-carbon supplementary cementitious material from EAF slag.
• Rapid slag cooling: system said to cool molten slag about 100 times faster than conventional methods.
• Mill integration: fits existing slag-handling operations at steel plants.
• Concrete performance: comparable to existing SCMs at 30% weight replacement.
• Third-party validation: material validated in concrete by an independent party.

Vietnamese cement producers could blend slag SCM to lower clinker use. Electric-arc steel mills could monetize slag. Ready-mix concrete suppliers could meet low-carbon project specifications.

The company states concrete embodied CO2 can fall by up to 40%. The SCM is described as cost-competitive with existing options. It gives cement producers an additional SCM source as coal ash and blast-furnace slag decline. Steel mills can turn slag waste into a product.

Supply of traditional SCMs is shrinking as coal plants and blast furnaces close, while cement makers face pressure to cut CO2. Vietnam has a large cement industry and a growing electric-arc steel sector, so slag-based SCMs are relevant.

Founded May 2023, London, UK. March 2026 Series A of USD 15 million led by 2150 and Brick & Mortar Ventures with The Venture Collective, Wireframe Ventures, Celsius Industries, Gigascale and SOSV; funds a first US commercial demonstration plant.