PHNX Materials has raised $2.5 million in seed funding to enhance concrete sustainability by utilizing fly ash from coal waste. The startup, co-founded by Krish Mehta and Jorge Osio-Norgaard, aims to replace up to 30% of cement in concrete, significantly reducing carbon emissions. Their innovative process purifies fly ash by removing sulfur and aluminum impurities, addressing the growing shortage of quality fly ash due to coal plant closures. By providing a lower-carbon alternative, PHNX seeks to revolutionize the construction materials industry while also offering extracted sulfur and aluminum to other sectors.