Microstructures and Properties of Carbon Refractories for Blast Furnaces with SiO^sub 2^ and Al Additions

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 41; no. 8; p. 2085
• Main Authors: Li, Yawei, Chen, Xilai, Sang, Shaobai, Li, Yuanbing, Jin, Shengli, Zhao, Lei, Ge, Shan
• Format: Journal Article
• Language: English
• Published: New York Springer Nature B.V 01.08.2010
• Subjects: Additives; Aluminum; Grain size; Microstructure; Pore size; Raw materials
• ISSN: 1073-5623; 1543-1940

Microstructures and properties of carbon refractories specimens for blast furnaces with SiO^sub 2^ and Al additions were investigated after coking for 3 hours at 1400 °C with the aid of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray, mercury porosimetry, and a thermal properties analyzer. Additives can influence the matrix structures and improve the properties of specimens. SiO^sub 2^ additions decreased the mean pore diameter and tremendously increased <1-µm pore volume by filling in the pores and matrix, resulting in an increased particle packing density. Addition of Al improved the thermal conductivity by the in-situ formation of well-developed Al^sub 4^C^sub 3^, AlN, and SiC whiskers. With double addition of SiO^sub 2^ + Al, not only the mean pore diameter decreased but also the thermal conductivity; <1-µm pore volume and cold crushing strength increased by combining the above mentioned superiority of single additive; and more SiC formed, providing greater assistance to improve such material properties. [PUBLICATION ABSTRACT]