Study on preparation technology and properties of calcium based CO₂ absorbent from acid leaching steel slag

Currently, more and more industrial carbon emissions lead to a significant increase in greenhouse gases, which has a significant impact on global climate change. Therefore, the storage and reuse of carbon dioxide is an important issue in modern society. In this paper, calcium based CO₂ absorbent was prepared from converter slag by acetic acid extraction and modification of steel slag. The study investigated the effects of parameters in indirect acetic acid leaching, including acetic acid concentration, leaching time, solid-to-liquid ratio, and temperature, on the elemental content in the adsorbent. It also compared the cyclic adsorbent stability of calcium-based adsorbents with commercial calcium oxide. The results indicated that the optimal technical parameters were: acetic acid concentration 1 ​mol/L, leaching time 40 ​min, solid-liquid ratio of 1:10, leaching temperature of 40°C, achieving an extraction rate of 88.05% for calcium elements. Its initial CO₂ adsorbent capacity is 0.51 g_CO2/g_adsorbent, and the CO₂ adsorbent capacity after 20 cycles is 0.202 g_CO2/g_adsorbent, and the inactivation rate is 60.39%. Compared with AR CaO, the adsorbent has more ideal CO₂ capture ability. © 2025 The Authors.