A New Approach to Steel Slag Recycling for Synergetic Desulfurization and Denitrification from Sintering Gas via High‐Temperature Mineral Reconstruction Technology

Relatively high‐efficiency and low‐cost steel slag adsorbents are prepared for desulfurization and denitrification in simulated sintering flue gas through high‐temperature mineral reconstruction technology. Steel slag adsorbents are successfully prepared at a holding temperature of 1300 °C with a picking concentration of 1% and an adsorption temperature of 200 °C, in which the T 90% value of the denitrification efficiency reaches 107.58 min, and the T 50% value of the desulfurization efficiency reaches 72.31 min. The results indicate that competition and synergistic adsorption between SO 2 and NO x can occur in the desulfurization and denitrification process of steel slag adsorbents. In the competition process, since the adsorption capacity for NO x is greater than that for SO 2 , the adsorption sites are preferentially occupied by NO x . Consequently, the desulfurization effect is inhibited in the adsorption process. The activation sites of free CaO in the steel slag adsorbents react with SO 2 and NO x to form a stable calcium nitrate or sulfate phase that blocks the adsorption sites, which in turn result in adsorbent poisoning. Moreover, unstable sulfur–nitrogen complexes can be captured by NO x and SO x in the synergistic adsorption process. This study provides a feasible strategy to address steel slag disposal and flue gas emission synergistically.