Abstract As an approach for reusing greater amounts of red mud, which has high CaO and Na 2 O content, batches of novel SiO 2 -Al 2 O 3 -CaO-MgO (10 wt%) ceramics that were mixed with 20 wt%, 35 wt% and 50 wt% red mud were prepared. Na + -leaching and physical properties of these ceramics were tested. Crystal evolution and sintering process were investigated using thermal gravity analysis-differential thermal analysis, X-ray diffraction, and scanning electron microscopy. Results showed that, although Na 2 O content in the ceramics increased from 2.15 wt% to 4.21 wt%, Na + -leaching rates of fired ceramics were almost constant and were about 6 times lower than that of green samples. Main crystal components were diopside ferroan, augite, and anorthite, each of which solidified Na + . Moreover, their solidifying abilities increased with increasing temperature. Of these components, anorthite had the greatest ability to solidify Na + . Ceramics with highest content of red mud (50 wt%) had lowest optimum sintering temperature of 1130 °C, widest sintering range from 1110 to 1140 °C and excellent properties, including a bending strength of 115.88 MPa, water absorption of 0.07%, Na + -leaching rate of 0.33%, and K + -leaching rate of 0.10%. This work provides important basis for long-term work on the reuse of red mud in the ceramics industry.

中文翻译：

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赤泥制备SiO 2 -Al 2 O 3 -CaO-MgO (10 wt.%)陶瓷的Na + -凝固行为

摘要 作为重复利用大量 CaO 和 Na 2 O 含量高的赤泥的方法，将一批新型 SiO 2 -Al 2 O 3 -CaO-MgO (10 wt%) 陶瓷与 20 wt% 混合，制备了35wt%和50wt%的赤泥。测试了这些陶瓷的 Na + 浸出和物理性能。使用热重分析-差热分析、X 射线衍射和扫描电子显微镜研究了晶体演化和烧结过程。结果表明，虽然陶瓷中 Na 2 O 的含量从 2.15 wt% 增加到 4.21 wt%，但烧成陶瓷的 Na + 浸出率几乎不变，比生坯低约 6 倍。主要晶体成分为透辉石亚铁、辉石和钙长石，均凝固Na + 。而且，它们的固化能力随着温度的升高而增强。在这些成分中，钙长石具有最强的凝固 Na + 的能力。赤泥含量最高（50 wt%）的陶瓷，其最佳烧结温度最低为 1130 ℃，最宽的烧结范围为 1110 至 1140 ℃，具有优异的性能，包括弯曲强度 115.88 MPa、吸水率 0.07%、Na + -浸出率为0.33%，K + -浸出率为0.10%。该工作为陶瓷行业赤泥回用的长期工作提供了重要依据。吸水率为0.07%，Na + -浸出率为0.33%，K + -浸出率为0.10%。该工作为陶瓷行业赤泥回用的长期工作提供了重要依据。吸水率为0.07%，Na + -浸出率为0.33%，K + -浸出率为0.10%。该工作为陶瓷行业赤泥回用的长期工作提供了重要依据。