Study on Mineral Compositions of Direct Carbonated Steel Slag by QXRD, TG, FTIR, and XPS

Energies

Keqing Li¹  Wen Ni¹  Siqi Zhang¹  Xue Wang¹  Jiajie Li¹ 

[1] School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China;

关键词: carbon capture;    orthogonal test design;    gypsum;    steel slag;    UCS;    XPS;   

DOI  :  10.3390/en14154489

来源: DOAJ

【 摘 要 】

Steel slag CO₂ sequestration helps mitigate global warming and decrease the stockpile of steel slag (SS). Through orthogonal design tests and single-factor tests, this paper evaluated the effects of the water/solid mass ratio (w/s), gypsum ratio (G/SS), molding pressure, and curing duration on uniaxial compressive strength (UCS) and CO₂ uptake of the compacts. The results indicated that high w/s enhanced both strength and CO₂ capture ability. The proper addition of gypsum helps promote UCS increase and CO₂ uptake of steel slag. In addition, increasing the molding pressure can significantly improve UCS without reducing CO₂ uptake. The optimum conditions in the study were a w/s of 0.20, G/SS of 1/16, and molding pressure of 27 MPa, under which conditions 1 d UCS and CO₂ uptake were 55.30 MPa and 12.36%, respectively. Microanalyses showed that gypsum activates mainly mayenite in steel slag. An increase in water addition also increased the hydration and carbonation products greatly, and the strengthened molding pressure had a significant densification effect on micro-pore structures. The study gives guidance in the application of steel slag in CO₂ capture and manufacturing green construction material.

【 授权许可】

Unknown