Abstract In-situ carbon-containing calcium aluminate cement (CCAC) was synthesized through carbon-bed sintering with calcium citrate tetrahydrate and Al2O3 as raw materials. The synthesized product was characterized by X-ray diffraction, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy, and infrared carbon–sulfur analysis. The results show that after sintering at 1500 °C for 4 h, the phase compositions of the product approached that of the commercial cement Secar71. The in-situ carbons in the product had partially graphitized domains and porous structures, were uniformly embedded in calcium aluminate, and the carbon content of the product was 1.45%. The floating ratios and oxidation ratios of the CCAC were lower than those of carbon back/Secar71 (S71CB) composite powders, implying that the water dispersion and oxidation resistance of CCAC were improved. Furthermore, the cold crushing strength (CCS), and cold modulus of rupture (CMOR) of the corundum-based castables bonded with CCAC, and S71CB, respectively, were compared. The CCS and CMOR values of the castables bonded with CCAC after being fired at 1100 °C for 3 h are higher by 20% and 21%, respectively, than those of the castables bonded with S71CB, suggesting that CCAC can be applied as a promising binder for the refractory castables.

中文翻译：

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原位合成含碳铝酸钙水泥作为耐火浇注料粘合剂的一步法

摘要 以四水柠檬酸钙和Al2O3为原料，通过碳床烧结合成原位含碳铝酸钙水泥（CCAC）。通过X射线衍射、场发射扫描电子显微镜、高分辨率透射电子显微镜、拉曼光谱和红外碳硫分析对合成产物进行了表征。结果表明，在 1500 °C 下烧结 4 h 后，产品的相组成接近商品水泥 Secar71 的相组成。产物中的原位碳具有部分石墨化畴和多孔结构，均匀嵌入铝酸钙中，产物含碳量为1.45%。CCAC的上浮率和氧化率低于炭背/Secar71（S71CB）复合粉体，表明 CCAC 的水分散性和抗氧化性得到了提高。此外，还比较了分别与 CCAC 和 S71CB 结合的刚玉基浇注料的冷抗压强度 (CCS) 和冷断裂模量 (CMOR)。CCAC 粘结浇注料在 1100 °C 烧制 3 h 后的 CCS 和 CMOR 值分别比 S71CB 粘结浇注料高 20% 和 21%，表明 CCAC 可作为一种有前景的应用。耐火浇注料的粘结剂。