Study on Carbon Dioxide Storage by Basic Oxygen Furnace Slag Carbonization Method

It is of great significance to realize the carbonation of Ca/Mg minerals in the basic oxygen furnace (BOF) slag. In this paper, the BOF slag was treated with hydrochloric acid and acetic acid, and the carbon dioxide storage test was carried out. The sample of the BOF slag was treated with acetic acid, in which the content of calcium, magnesium, and silicon accounted for 45.44%, 8.23%, and 6.83%, respectively, and has a BET surface area of 52 m2/g. The thermodynamic analysis results were that the BOF slag can react with carbon dioxide at room temperature to form carbonate. However, better kinetic conditions were needed to obtain the maximum carbon dioxide absorption capacity. The amount of carbon dioxide absorbed by the sample at 25–900 °C was measured. The results showed that in the range of 50–400 °C, the largest amount of carbon dioxide was absorbed by the sample treated with acetic acid, and the absorption amount was between 2.6 and 4.1 mmol/g. In the range of 500–800 °C, the largest amount of carbon dioxide absorbed was lime treated with acetic acid and hydrochloric acid, and the absorption was between 4.2 and 6.0 mmol/g. In the 800–900 °C range, the largest amount of carbon dioxide was absorbed, and the absorption was between 6.0 and 6.9 mmol/g via the samples treated with acetic acid and hydrochloric acid.