Slurry-Phase Carbonation Reaction Characteristics of AOD Stainless Steel Slag

Abstract

Argon oxygen decarburization stainless steel slag (AOD slag) has high mineral carbonation activity. AOD slag carbonation has both the resource utilization of metallurgical waste slag and the carbon reduction effect of CO2 storage. This paper aimed to study carbonation reaction characteristics of AOD slag. Under the slurry-phase accelerated carbonation route, the effect of stirring speed (r) and reaction temperature (T) on AOD slag’s carbonation was studied by controlling the reaction conditions. Mineral composition analysis and microscopic morphology analysis were used to explore the mineral phase evolution of AOD slag during the carbonation process. Based on the unreacted core model, the kinetic model of the carbonation reaction of AOD slag was analyzed. The results showed that the carbonation ratio of AOD slag reached its maximum value of 66.7% under the reaction conditions of a liquid to solid ratio (L/S) of 8:1, a CO2 partial pressure of 0.2 MPa, a stirring speed of 450 r·min−1, and a reaction temperature of 80 °C. The carbonation reaction of AOD slag was controlled by internal diffusion, and the calculated apparent activation energy was 22.28 kJ/mol.

Interpretation and Prediction of the CO2 Sequestration of Steel Slag by Machine Learning

“…Figure a indicates that parameters, such as “carbonation time”, “MgO”, “temperature”, “CaO”, “L/S”, “CO 2 partial pressure”, and “particle size”, showed impacts on CO 2 sequestration that were consistent with the results of previous literature. , These influencing factors have been widely studied and have gained a relatively unified understanding. ,, Therefore, this section mainly targeted unique parameters for further analysis. In particular, the positive impact of Fe 2 O 3 on the output will be discussed in depth in section .…”

“…5,58 These influencing factors have been widely studied and have gained a relatively unified understanding. 21,27,29 Therefore, this section mainly targeted unique parameters for further analysis. In particular, the positive impact of Fe 2 O 3 on the output will be discussed in depth in section 3.2.…”

“…There are many factors that affect the carbonation of steel slag, including temperature, pressure, CO 2 concentration, liquid-to-solid ratio (L/S), and steel slag composition (CaO, Fe 2 O 3 , SiO 2 , Al 2 O 3 , MgO, MnO, and so on). − Investigation of these factors is complex, time-consuming, and troublesome, which makes it difficult to maintain repeatability and universality among independent studies. Previous studies showed different optimal conditions of CO 2 sequestration when facing different steel slag. − In order to comprehensively investigate the CO 2 sequestration of steel slag and the influence of various factors, a more scientific data analysis method was needed.…”

Prospects for green steelmaking technology with low carbon emissions in China

“…This includes the utilization of captured CO 2 to produce highvalue products, such as synthetic minerals [11][12][13] and fuels 14 (e.g., hydrocarbons and methanol) and the carbonation of minerals in slag to store the captured CO 2 permanently. 15,16 Although these two technologies are favored by researchers, their capacity to absorb CO 2 is limited, and it is not possible to consume all the CO 2 captured from large point sources. 17 Further, the steel industry is a major point source of CO 2 emissions.…”

“…Within the currently mature carbon‐trading market, support for CCS/CCUS (Carbon Capture, Utilization, and Storage) and CCU technologies is necessary to realizing their potential. This includes the utilization of captured CO 2 to produce high‐value products, such as synthetic minerals 11–13 and fuels 14 (e.g., hydrocarbons and methanol) and the carbonation of minerals in slag to store the captured CO 2 permanently 15,16 . Although these two technologies are favored by researchers, their capacity to absorb CO 2 is limited, and it is not possible to consume all the CO 2 captured from large point sources 17 .…”