Cement-Free Concrete and High-Grade Minerals From Waste
More than 136 million tons of coal ash waste materials are being produced to meet the electricity needs of the US each year. However, more than 55% of these wastes are being dumped in the landfills and ash ponds. Many studies indicate the presence of a variety of metal oxides such as Iron, Aluminum and Titanium in these wastes. Another application envisioned is to make cement-less concrete using these materials to reduce the Portland cement consumption which is responsible for 5-8% of total CO2 emissions as a greenhouse gas.
The main objective of this study was to develop a novel flowsheet for extracting valuable metal oxides from coal ash wastes and to develop a suitable process to utilize them as a useful product in the form of a cement-less concrete. We used totally waste materials to produce some useful metals and also cement-less concrete with much less carbon footprint. We not only left nothing behind as waste but also helped the climate and prevented global warming by decreasing carbon dioxide production.