Effect of in-situ carbon containing calcium aluminate cement on properties of Al₂O₃-SiC-C based trough castables

Abstract

The properties of Al 2 O 3-SiC-C castables bonded by in-situ carbon containing calcium aluminate cement (CCAC) were investigated in this study. The results showed that after the Al 2 O 3-SiC-C castables were dried at 110°C, their cold crushing strength (CCS) and cold modulus of rupture (CMOR) increased with the percentage of CCAC. The sample with CCAC content exceeding 2.5% by mass (named C2.5) had higher CCS and CMOR values than those of the model Al 2 O 3-SiC-C castables (named BPS) with ball pitch as the carbon source. After being fired at 1100 and 1450°C, all the castables exhibited increased CCS and CMOR values, while the high apparent porosity of the BPS sample lowered its CCS and CMOR values. Compared with the BPS sample, the carbon materials of the castables bonded by CCAC exhibited improved dispersion in the matrix and excellent oxidation resistance, which enhanced the corrosion resistance of the refractory castables.

Study on cobweb‐like carbon nanotubes/calcium aluminate cement and its effect on the properties of Al2O3–SiC–C castables

“…The content of carbon in the EDS results of spot B was higher than that of spot A, which can be inferred that the cobweb‐like matter is carbon, as indicated by the red arrows. The cobweb‐like carbon was bound firmly between calcium aluminate grains, which was different from the flake‐like pyrolytic carbon of HCCAC 21 . The formation of this cobweb‐like carbon may result from the entanglement and agglomeration of CNTs.…”

“…If I D / I G >1, it indicates that the carbon has more lattice defects, which cannot be identified as graphitized carbon. In previous study, 21 it had been proved that the carbon matter in HCCAC was formed in the dehydrogenation and carbonization process of organic precursors, and this pyrolytic carbon was amorphous, showing low graphitization degree. According to the full width at half maximum (FWHM) of the G peak and I D / I G of carbon, an evaluation method for the graphitization degree was proposed by Ammer et al.…”

“…Besides, the preparation of carbon spheres is more complex and difficult for practical application. Several studies are focused on the combination of carbon materials with the matrix, such as carbon-containing cement [21][22][23][24][25] or carbon composite powders, 26,27 aiming to improve the poor water wettability of carbon through the combination predesign of carbon/hydrophilic inorganic. In our previous work, we have prepared an in situ high-content carbon-containing calcium aluminate cement (HCCAC), 21 in which the in situ carbon is embedded on the calcium aluminate grain with good hydrophilicity to solve the problem of water wettability of carbon.…”

Carbon Raw Materials on the Properties of Al2O3-SiC-C Iron Trough Casting Building Materials

“…The purpose of calcination is to make the material undergo a series of physical and chemical changes under high temperature conditions, thereby eliminating moisture changes in the raw materials, increasing the weight and mechanical strength of the raw materials, and improving the strength and chemical stability. Promote the evaporation of the monomer carbon in the raw materials and the accumulation of sulfur, so that the physical and chemical properties of the raw materials after combustion are significantly improved [9].…”