Carbon-dioxide fixation by artificial reef development in marine environment using carbonated slag material from steel plant

Carbon dioxide emission into the atmosphere from the major point sources such as coal fired power plants, steel plants, cement industries triggered studies on its green house effects. Mineral carbonation is an option for storage of carbon dioxide in industrial waste materials by converting it into carbonates similar to the end products of natural weathering processes. Present study deals with carbonation of steel slag for carbon dioxide storage and also utilization of the converted carbonates in structures for shore protection. Blast furnace slag and Linz-Donawitz converter slag are subjected to high pressure (>20 bar) and temperatures above 60°C in presence of carbon dioxide in a reactor to convert into carbonate. Laboratory experiments showed encouraging results with a 50% conversion of less than 75μm sized slag into carbonate. Converted carbonates are proposed to be utilized in the development of artificial reefs and the laboratory studies on the behavior of the material in sea water are conducted. Details of the carbonation of steel slag and preparation of structures for artificial reef development are discussed in the paper.