Basalt-based cement could slash emissions

Researchers are exploring a novel method for producing Portland cement using basalt rock instead of traditional limestone, potentially eliminating significant CO2 emissions. Cement production currently accounts for about 8 percent of global greenhouse gases, largely due to direct emissions released when heating limestone. This new approach, detailed in Communications Sustainability, involves leaching calcium from basalt and processing it into cement with only water vapor as a byproduct. While the process may require more energy than current methods, it offers a substantial reduction in CO2, especially if powered by clean electricity, and could also yield valuable byproducts like iron and aluminum.