|
级别
|
SiO2（质量分数，%）≥
|
有害杂质含量（质量分数，%）≦
|
耐火度℃
|
外观
|
||
|
K2O +Na2O
|
CaO+MgO
|
Fe2O3
|
||||
|
98
|
98
|
1.0
|
0.1
|
≥1700
|
洁白
|
|
|
97
|
97
|
1.5
|
0.2
|
≥1650
|
个别沙粒有锈迹
|
|
|
96
|
96
|
2.0
|
0.3
|
≥1650
|
个别沙粒有锈斑
|
|
