Fabrication and properties of MgO–C refractories improved with expanded graphite

Effect of the reactivity and porous structure of expanded graphite (EG) on microstructure and properties of Al2O3–C refractories

“…Consequently, it is easier for the EG to contact with the matrix and aggregates. Meanwhile, the EG could filled the space between big refractory particles easily to densify the samples [39], which resulted in the higher bulk density and lower apparent porosity for the specimen E2 and specimen E5. However, lots of micro-pores between the graphitic layers of the EG were observed due to the excess EG amount (Fig.…”

“…In fact, the expanded graphite (EG) with high reactivity and large surface area could be regarded as parallel sheets assembly of countless graphene or GONs. Therefore, several researchers ever attempted to introduce the EG into MgO-C refractories [38,39]. Hayashi et al [40] reported that the maximum values of the bending strength, elastic modulus and fracture toughness were obtained for MgO-C bricks with 2-3 vol% expanded graphite and 5 vol% graphite flake.…”

Study of dynamic refractory wear by slags containing very high FeO contents under steelmaking conditions

“…Additions of carbon to magnesite refractories reduce the wetting of slag and thus reduce the refractory wear. Higher amounts of C in the refractory increase the C loss by oxidation from slag due to a formation of CO and CO 2 , which reduces the structural integrity of the refractory [21]. Since MgO has no liquid phase in contact with FeO x or Fe 2 O 3 , the wear by corrosion should in theory not increase with increased amounts of FeO x in the slag [22].…”

Development of an Ultra-Low Carbon MgO Refractory Doped with α-Al2O3 Nanoparticles for the Steelmaking Industry: A Microstructural and Thermo-Mechanical Study

“…Nevertheless, serious drawbacks can ensue with higher carbon content, such as (i) oxidation of carbon results in a highly porous structure with weak bonding, poor mechanical strength that allows easy penetration, and eventual corrosion by slag and molten steel; (ii) increased shell temperature; (iii) higher energy consumption originated by increased conductivity of the refractory; (iv) release of carbon dioxide or carbon monoxide gases; and (v) difficulty in precisely controlling the carbon content in steel [5,13,[16][17][18][19]. Certainly, the particular sensitivity of carbon with respect to oxygen is the major defect of MgO-C refractories.…”