New periclase-spinel refractories from densely sintered high purity magnesite and new synthetic compositions based on spinel. Part 1. Study of mineral composition, microstructure, thermal expansion, and ultimate strength in compression

摘要: Six specimens of magnesia-spinel material are made under laboratory conditions. Specimens prepared at 1600°C from sintered magnesite and three different compositions based on spinel, previously synthesized 1760 °C. Sintered spinel properties provided. Raw in relation to content within them, apparent density, additions introduced, also their effect final product, shown. Three forms product contain 8 – 11 wt.% Al2O3, the rest 19 21 Al2O3. Photographs taken a scanning electron microscope, results microstructural analysis raw point formation direct periclase–periclase periclase–spinel bonds, secondary calcium aluminate silicate phases. Secondary is detected form solution periclase, grain boundaries refractories. On basis petrographic criteria (mineral composition, microstructure), linear thermal expansion coefficient (LTEC) ultimate strength compression for materials, authors this article propose most suitable with respect quality testing high-temperature branches industry.