Magnesia–chrome brick has been abandoned in the use of Ruhrstahl Heraeus (RH) degasser in China for hexavalent chromium (Cr⁶⁺), a reaction product, is classified as carcinogenic potential. Because continuous Al-leading reaction behind the hot face results in the formation of a dense network of interwovenwhisker in the matrix as temperature gradient moves, an unburnt periclase–spinel–Al brick has been affirmed as an alternative, with an advanced bonding system that can effectively reduce the penetration of slag and Fe melt,generate superior flexibility and hot strength to resist rapid-flow melt attack and thermal circulations, and present minor positive value of permanent expansion to ensure the closed joints of monolized lining when switching to lower temperature. A whisker bond is defined to be critical for the pronounced performance and extensive application of the unburnt periclase–spinel–Al bricks in RH degassers to substitute magnesia–chrome brick in steel refining process.