Displaying items by tag: olivine
UK: Seratech has developed a process using olivine, a mineral abundant in Earth's mantle, to produce ‘carbon-negative’ cement. The company's method involves replacing some of the clinker with silica extracted from olivine. Magnesium sulphate derived from the olivine reacts with CO₂ to form nesquehonite, a mineral that sequesters CO₂. This method uses CO₂ captured from emissions sources or directly from the air.
Sam Draper, CEO, explained the process: “The researchers extracted these compounds by dissolving powdered olivine in sulphuric acid. After separating the silica and magnesium sulphate, they bubbled CO₂ through the magnesium slurry to form nesquehonite.”
According to Draper, replacing 35% of regular cement with this silica would yield carbon-neutral results, while a 40% substitution could achieve carbon negativity. Current building standards allow up to 55% of cement to be replaced by this material, although robust testing has yet to be conducted.
Imperial College London team secures government funding for carbon negative cement development
20 July 2023UK: A team at Imperial College London has won a US$1.27m grant for its research into developing carbon negative cement from silica. The research won the Department for Energy Security and Net Zero (DESNZ)’s Carbon Capture, Usage & Storage (CCUS) Innovation 2.0 competition. The Imperial team sources its silica from natural olivine. It says that the compound behaves in the same way as other supplementary cementitious materials. Meanwhile, magnesia from the decomposition of the olivine can serve as a carbon sink in the form of magnesium carbonate. It, in turn, could serve as a raw material for concrete block production.
The DESNZ’s Net Zero Innovation Portfolio, of which the CCUS Innovation 2.0 competition is a part, has a budget of US$1.29bn.