Carbon-negative cement can be made with a mineral that helps catch CO2
https://www.newscientist.com/article/2428967-carbon-negative-cement-can-be-made-with-a-mineral-that-helps-catch-co2/
Carbon-negative cement can be made with a mineral that helps catch CO2
A process to dissolve the mineral olivine in acid could provide a plentiful, energy-efficient material for carbon-negative cement
By James Dinneen
1 May 2024
An abundant mineral called olivine can help make carbon-negative cement. This process could help tackle cements large carbon footprint the material contributes about 8 per cent of global CO2 emissions.
Olivine is one of the main components of Earths mantle and reserves sit on every continent. Its one of the few minerals that is available at the gigatonne scale, says Sam Draper at Seratech, a UK-based company that has patented a process to turn olivine into cement.
Dozens of start-ups like Seratech are developing low-carbon methods to produce cement, such as supplementing with steel by-products or recycling the CO2 released in cement production. Most emissions occur when heating limestone to produce clinker, a binder in cement, along with burning fossil fuels to generate the heat.
Draper and his colleagues looked to the more abundant olivine to find a replacement for some of the usual clinker. Olivine contains silica, which makes cement stronger and more durable. Magnesium sulphate can also be extracted from it, and this salt reacts with CO2 to form minerals that sequester the gas.
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Journal reference
Royal Society Open Science DOI:
https://doi.org/10.1098/rsos.231645