高性能镁尖晶石质浇注料的研制

Development of high performance magnesia-spinel based castable

以不同粒度的电熔镁砂(≤8、≤0.088 mm)和铝镁尖晶石细粉(≤0.088 mm)为主要原料,经振动成型制备了一系列镁尖晶石质浇注料试样,探讨了镁质结合剂和活性氧化铝微粉加入量(w)分别为1%、2%、3%、4%和5%时对浇注料试样分别经110、1 000和1 600℃热处理后物理性能的影响,并将优选的合适配方试样与RH炉用烧成镁尖晶石砖进行了常规物理性能、抗热震性能和抗渣性能比较。结果表明:当镁质结合剂加入量(w)由1%增至2%时,试样经不同温度处理后的强度显著增加;但当其加入量超过2%(w)后,试样经不同温度处理后的强度尤其是在1 450℃的高温抗折强度逐渐向相反的方向变化;当活性氧化铝微粉加入量(w)由1%增至3%,试样经110℃热处理后的强度下降较快,但经1 000和1 600℃热处理后的强度和线膨胀率及高温抗折强度却呈现增加的趋势;当加入量超过3%(w)后,试样的高温抗折强度开始下降。研制的镁尖晶石质浇注料经1 600℃处理后具有较高的致密度及骨料和基质间存在微细裂纹的特征,与烧成镁尖晶石砖相比,具有较好的抗热震性能、抗渣性能和较低的高温强度。

A series of magnesia-spinel based castable specimens were prepared by vibration method using fused magnesite （ ≤8 and ≤0. 088 mm） and spinel powder（ ≤0. 088 mm） as main starting materials. Influ-ences of magnesia-containing binder and active alumina micropowder additions （both were 1% ,2% ,3%, 4% ,and 5% in mass, respectively） on physical properties of castable specimens treated at 110,1 000 and 1 600 ℃, respectively, were discussed, and the castable specimen based on the appropriate formulation was compared with fired magnesia-spinel based brick for RH degasser on physical properties,thermal shock resistance and slag resistance. The results show that when the magnesia binder addition increases from 1% to 2% ,the strengths of the specimens fired at different temperatures increase obviously, but when it exceeds 2%, the strengths of the specimens fired at different temperatures, especially hot modulus of rupture at 1 450 ℃, decrease gradually;when active alumina micropowder addition increases from 1% to 3% ,the strength of the specimens treated at 110 ℃ decreases quickly,but the strength and linear expan-sion rate of the specimens fired at 1 000 and 1 600 ℃ as well as hot modulus of rupture increase significant-ly;however,when active alumina micropowder addition exceeds 3%, hot modulus of rupture begins to de-crease ; compared with fired magnesia-spinel based brick, the designed castable specimen fired at 1 600 ℃ has the characteristics of high density and micro-cracks existence between the aggregates and the matrix, so it has better thermal shock resistance and slag resistance but lower strength at high temperatures.