Magnesia-Zirconia Brick

In terms of corrosion resistance, magnesia-zirconia brick surpasses magnesia-chrome bricks, and in terms of high-temperature resistance and thermal shock resistance, it surpasses magnesia bricks.

Application

Glass melting furnaces, electric furnaces, cement kiln.

Description

Magnesia-zirconia bricks are manufactured primarily from high-purity microcrystalline electrofused magnesite and zircon sand. At high temperatures, ZrSiO₄ decomposes and reacts with MgO to form M₂S and ZrO₂, which create a protective layer around the periclase, preventing cracking caused by the reaction of SO₃ with MgO to form MgSO₄. Simultaneously, the phase transformations of ZrO₂ during the high-temperature sintering process generate microcracks that effectively relieve thermal stress and prevent product cracking.

Specifications

Item	MZ8	MZ10	MZ13
MgO %	≥80	≥75	≥70
ZrO₂ %	≥8	≥10	≥13
Apparent Porosity %	≤19	≤18	≤18
Bulk Density, g/cm³	≥2.95	≥3.0	≥3.05
Cold Crushing Strength (CCS), MPa	≥50	≥45	≥40
Refractoriness Under Load (RUL) 0,2 Mpa	≥1600	≥1550	≥1600
Thermal Shock Resistance, 950°C – water (cycles)	≥10	≥10	≥10

Applications

Magnesia-zirconia brick possesses excellent corrosion resistance and thermal shock resistance, making it an ideal material for the top and bottom layers of regenerator checkerwork in glass melting furnaces. In practical applications, magnesia-zirconia brick demonstrates a unique combination of properties. For example, when used in the high-temperature zone of cement rotary kilns, its coating formation ability is inferior to that of magnesia-dolomite bricks; however, its thermal shock resistance significantly surpasses the latter. Compared to magnesia-spinel bricks, which possess a comprehensive set of high performance characteristics, magnesia-zirconia bricks still lag somewhat in thermal shock resistance. Nevertheless, under specific operating conditions, the balance between cost and performance makes them a highly competitive choice.