Mevocrete

An ultra-low carbon cement that utilises material from the ‘urban mines’ of industrial slag heaps is set to transform the construction industry and put the UK at the forefront of green cement production

A groundbreaking ‘green’ cement facility is accelerating the construction industry’s journey to net zero and reducing the impact of industrial waste.

As part of the £7.6m Mevocrete project, green cement company Material Evolution has established a manufacturing site in Wrexham to develop and scale production of its ultra-low carbon cement technology.

Cement manufacturing is a major contributor to greenhouse gas emissions. In the UK alone, production plants produced over 9m tonnes of cement in 2019, equating to over 700m tonnes of CO_2. In recent years, lower-carbon cement alternatives made with waste from the steel industry have proved effective. However, the blast furnaces from which this waste emanates – known as ground granulated blast furnace slag (GGBS) – are being phased out in favour of more energy-efficient electric arc furnaces (EAFs).

Material Evolution’s innovative cement, ‘MevoCem’, not only uses a less energy-intensive process to produce – using no heat compared to 1500 degrees Celsius for traditional cement – but also aims to incorporate alternative byproducts from the steel industry. “There are billions of tonnes of industrial mineral wastes globally, including historic steel slags, mineral wastes and EAF slags, which have the potential to replace GGBS as a cementitious material in lower-carbon concrete. Our technology uses alkali-fusion, geopolymer chemistry and advanced algorithms to create bespoke mixes from these untapped waste streams,” explains Professor David Hughes, Chief Scientific Officer at Material Evolution and co-lead of the Mevocrete project. “The result is a cement with up to 85% less embodied CO₂ that performs the same way as conventional Portland cement and reduces the need to extract raw materials.”

Largest UK manufacturer and supplier of ultra-low carbon cement

With £2.98m funding from the Transforming Foundation Industries (TFI) challenge, the Mevocrete project included partners from across the entire concrete supply chain to develop and scale production of MevoCem.

Material Evolution designed and built a new production facility capable of producing 120,000 tonnes of MevoCem annually. “Although that’s relatively small in terms of Portland cement production, it has positioned us as the largest producer of ultra-low carbon cement in the UK, and one of the largest in the world,” says Prof Hughes. “The plant has also been key to refining production processes and demonstrating how our technology performs when produced in industrial quantities rather than lab batches.”

With an eye on the next step in innovation, the company worked with Teesside University to explore formulations that sequester carbon, creating the potential for the production of carbon-negative cement at the Wrexham factory in future.  

Establishing high-volume feedstocks

Through previous projects funded by the Transforming Foundations Industries small and large-scale R&D programme, Material Evolution developed technologies and formulations to incorporate waste streams into its ultra-low carbon cement. The Mevocrete project digitally mapped active and historic steel waste to establish availability, logistics and potential supply constraints for the high volumes and consistency demanded by industrial production.

The team worked with the Materials Processing Institute to identify and test alternative feedstocks. They are also running full-scale trials with Celsa Steel UK to explore how steel-making processes could be altered to create slags more suited to cement production.

AI algorithms to predict the performance of waste materials

Historic waste heaps are often inconsistent in their make up, so the project team developed an artificial-intelligence driven app that analyses the constituents of a waste sample and predicts with more than 90% accuracy how it would perform in a cement. “That model could be applied all over the world to identify – often risky – wastes and transform them into a cement product that will benefit the region,” says Prof Hughes.

Slag heaps often contain valuable metals, such as zinc, so Material Evolution worked with project partners Enursan Ltd and Nanomox Ltd to develop processes to recover those materials before waste is converted into cement.

Commercial trials of green concrete

Demonstration pours were conducted with engineering and concrete specialists ZTL Contracting and Retaining UK. These included commercial trials of concrete products, such as walling blocks and pavers; a standard ready-mix for pouring into slabs; and a soil stabiliser for securing uneven ground prior to construction work.

“We believe the future cement market won’t be formed by a single product like it has in the last 100 years, but by multiple solutions,” says Prof Hughes. “However, the construction industry must go on a journey with alternative cements. Mevocrete’s demonstrations are helping to build confidence and understanding about where and how best to use low-carbon cements, and their potential to transform the industry.”

Global industrial minerals supplier LKAB assisted with processing materials for the demonstration projects, drawing on their extensive knowledge and infrastructure, which aligns with the company’s commitment to building a sustainable future.

Rejuvenating brownfield sites

Material Evolutions plans to replicate and scale its production process for ultra-low carbon MevoCem, as well as future innovations in carbon-negative cement, across the UK and Europe. This planned growth represents advantages to the UK, which currently imports around 5 million tonnes of cement a year, along with cementitious materials like GGBS for use in UK cement production. For a critical industry such as cement, Material Evolution’s technology not only offers significant carbon savings but also supply chain security.

It also provides a way to redress the “sins of the past”, says Prof Hughes. “These industrial wastes are all around the country, potentially leaching chemicals into waterways and preventing development on brownfield sites because they are difficult to treat. Our technology aims to take that liability and transforms it in something sustainable that can be used to rejuvenate an area,” he explains.  

“Take a site like the Teesworks – the largest brownfield development site and regeneration project in Europe – which has around 20 million tonnes of liability materials on it, and also the need for millions of tonnes of concrete. Our technology could convert that waste into products to use on site, decarbonising the construction and making the ground safe. What we need now is appetite from government and regulators to utilise these ultra-low carbon cement technologies at scale, creating transformative impact and building a greener tomorrow.”