Oxide Structure And Properties Of The Calcium-based Refractories

Calcium oxide grogs are prepared at 1600℃ using CaO raw material with CeO₂,La₂O₃, Y₂O3 added. Using those kinds of grogs, CaO briquette are made, and parts of them are sintered at 1600℃. The influence of additives on hydration resistance property of CaO grogs, CaO briquettes and products are studied by constent temperature and humidity method and boiling method. The preparation and application of CaO crucible in high temperature smelting alloy are introduced.The study result of influence of additives on hydration resistance property of CaO grogs shows that CeO₂, La₂O₃, Y₂O₃ can improve the hydration resistance property of CaO material effectively, and CeO₂, La₂O₃ are better than Y₂O₃ in improving the hydration resistance property. The weight increase ratio of samples with the three kinds of additives addition decrease gradually after hydration when the amount of additives changes from 0.0% to 0.6%(or 0.8%), then it increases gradually when the amount of additives changes from 0.6%(or 0.8%) to 1.0%. The optimum addition of the three additives is 0.6-0.8%.The study results of influence of additives on hydration resistance property of CaO briquette and products shows that the hydration degree of briquette without additives is more serious than the briquettes with additives in air atmosphere for 6 hours. The hydration resistance property of products with additives is better than the products without additives.The physical properties of specimens made of CaO grogs with additives are better than those of specimens without additives.The CaO material with additives possesses bigger bulk density and less apparent porosity.The application of CaO crucible in high temperature smelting alloy in vacuum induction furnace was introduced. The results show that using CaO crucible in high temperature smelting alloy is better than other materials. The EDAX analysis of crucible being used shows that CaO crucible can purify sulphur in alloy .