Magnesia Alumina Spinel Brick Introduction

Magnesia-Alumina Spinel Brick is in order to improve the heat stability of magnesia brick, add alumina oxide in ingredient to generate the magnesia brick which the main material is magnesia-alumina spinel.

The advantage of magnesia-alumina spinel brick:

Good heat stability, in the process of use, it will have reaction with clinker and produce a thin layer of calcium aluminate maskant, which makes the liquid not easy to penetrate, its anti-stripping performance is better than the direct bonded magnesia chrome brick.

Application of Magnesia Alumina Spinel Brick

1.The magnesia-alumina spinel can be used in the cement kiln, not only avoid the chrome pollution, and has good anti-stripping performance. 2.It can be used in refractory carstables for ladles, which greatly improve the anti-erosion ability. It is widely applied to steel-making refractory material. The preparation of high quality pre-synthertic spinel provide a new material for amorphous and fixed high purity refractory.

Magnesium-alumina spinel bricks have the following advantages.

① The elastic modulus is small, magnesia alumina brick is (0.12~0.228)×105MPa, while magnesia brick is (0.6~5)×105MPa; ② MA can transfer MF from periclase and sweep FeO, and the reaction is as follows: FeO+MgO • AI2O3→MgO+FeAl2O4 FeO+MgO→(Mg • Fe)O MA absorbs Fe2O3 and undergoes minor expansion ③ High melting point. The melting point of spinel is 2135 ℃, and the initial melting temperature of periclase is 1995 ℃ higher. The combination of the two will improve the bonding performance of magnesia bricks. ④ The softening temperature under load is high, but the spinel formation is accompanied by volume expansion, and the ability to aggregate and recrystallize is weak, so a higher firing temperature is required. ⑤ Excellent thermal shock resistance. ⑥ High strength. ⑦ Strong corrosion resistance.

Items	Magnesia Alumina Spinel Brick
	MA-12A	MA-12B	MA-12C	MA-18
MgO%	80	75	70	60
SiO2%	1.0	1.0	1.5	1.0
Al2O3%	12	12	12	18
Bulk density(g/cm³)	2.95	2.90	2.90	2.85
Apparent porosity	18	18	18	18
Cold Crushing strength Mpa	40	40	40	40
Refractoriness under load 0.2Mpa	1650	1650	1650	1650
Thermal shock resistance(950℃air cool times)	40	40	40	40
Application	Severe corrosion area	Larger than 5000mt/d kiln capacity	Economic solution	Severe corrosion area