Despite the reduced alumina content , the tensile strength of magnesia - hercynite and magnesia - galaxite bricks is kept at a much higher level compared to conventional top grade ma - spinel bricks even at high temperatures ( 1100 ) 尽管减少了氧化铝的含量,但即使是在1100度的高温下,镁铁尖晶石砖和镁锰尖晶石砖的抗拉强度仍然比常规的顶级镁铝尖晶石砖高很多。