Co-treatment of Waste From Steelmaking Processes: Steel Slag-Based Carbon Capture and Storage by Mineralization

Abstract

The iron and steel industry is an energy-intensive sector, and large amounts of waste/ by-products are generated during the steelmaking process, such as CO 2 , metallurgical slag, and wastewater. Enhancing the development and deployment of treating waste from the steelmaking process will be environment friendly and resource-saving. Capturing CO 2 by steel slag (SS) via mineralization is regarded to be an excellent choice due to the high basicity of the slag. In this paper, recent research on the steel slag-based carbon capture and storage (SS-CCS) by mineralization was summarized. Three routes of SS-CCS are compared including, direct gas-solid carbonation, direct aqueous carbonation, and indirect carbonation, respectively. Furthermore, the challenges and prospects for further development of the SS-CCS were discussed.

Enzyme-accelerated CO2 capture and storage (CCS) using paper and pulp residues as co-sequestrating agents

“…Industrial residues rich in oxides 33 and hydroxides 34–37 have high CO 2 affinity and have proven their potential for carbon capture; 38,39 however, materials rich in carbonates without previous treatment ( i.e. , calcination, acidification) have been not widely exploited in the literature in direct carbonation studies, since they are not as reactive as their decarbonated forms.…”

Synthesis of High-Purity and Stable Vaterite Via Leaching–Carbonation of Basic Oxygen Furnace Slag

“…In direct carbonation, BOFS is directly carbonated to form CaCO 3 attached on the surface of particles and can be used as a construction material. , Carbonated BOFS powder can replace 10–30% cement, and the presence of nanocarbonates can accelerate early hydration and formation of carboaluminate, enhancing the mechanical and durability performances of mortar or concrete. , Furthermore, direct carbonation can induce rapid BOFS hardening, rendering it a carbon-negative binder to produce cementless building products, such as shaped blocks and artificial aggregates. − However, one drawback of the direct carbonation of the BOFS is that the produced layer on the surface could delay further leaching of Ca from the BOFS and its subsequent reaction with the unreacted phases. This problem can be addressed by indirect carbonation, which involves a multistep reaction process, including Ca leaching and subsequent aqueous carbonation, in which the ex-situ generation of CaCO 3 is facilitated . Indirect carbonation also has the advantage of yielding a high-purity precipitated calcium carbonate (PCC) for higher value-added applications in the fields of plastic, rubber, food, pharmaceuticals, paints, coatings, paper, etc. , …”

“…This problem can be addressed by indirect carbonation, which involves a multistep reaction process, including Ca leaching and subsequent aqueous carbonation, in which the ex-situ generation of CaCO 3 is facilitated. 12 Indirect carbonation also has the advantage of yielding a high-purity precipitated calcium carbonate (PCC) for higher value-added applications in the fields of plastic, rubber, food, pharmaceuticals, paints, coatings, paper, etc. 13,14 Numerous studies have successfully extracted calcium ions from BOFS using acid (CH 3 COOH, HCl, H 2 SO 4 ) and ammonium salts (NH 4 Cl, NH 4 NO 3 , (NH 4 ) 2 SO 4 ), followed by a subsequent set of aqueous carbonation to produce PCC, 15−17 with some studies advancing to pilot-scale experimentation.…”

“…21 the Ca leaching ratio from the NH 4 Cl solution is lower (<60%) due to its weaker acidity, and the NH 3 overflow further reduces the Ca leaching efficiency. 12 To address these drawbacks, researchers have employed high-energy stimuli (microwave, ultrasound, etc.) or multistep leaching methods to enhance the Ca leaching efficiency and produce more PCC.…”

“…Numerous studies have successfully extracted calcium ions from BOFS using acid (CH 3 COOH, HCl, H 2 SO 4 ) and ammonium salts (NH 4 Cl, NH 4 NO 3 , (NH 4 ) 2 SO 4 ), followed by a subsequent set of aqueous carbonation to produce PCC, − with some studies advancing to pilot-scale experimentation. − Compared with acid, NH 4 Cl exhibits a higher selectivity for Ca leaching, pH buffering properties, and a higher carbonation conversion rate, which is a more suitable leaching agent for indirect carbonation of BOFS . However, the Ca leaching ratio from the NH 4 Cl solution is lower (<60%) due to its weaker acidity, and the NH 3 overflow further reduces the Ca leaching efficiency . To address these drawbacks, researchers have employed high-energy stimuli (microwave, ultrasound, etc.)…”