normal align=center>硼镁石矿石质量标准

normal align=center>指标名称

normal align=center>等级

normal align=center>优等品

normal align=center>一等品

normal align=center>二等品

normal align=center>三等品

normal align=center>优-1

normal align=center>优-2

normal align=center>Ⅰ-1

normal align=center>Ⅰ-2

normal align=center>Ⅱ-1

normal align=center>Ⅱ-2

normal align=center>Ⅲ-1

normal align=center>Ⅲ-2

normal align=center>三氧二化硼（B2O3）质量分数% ≥

normal align=center>24

normal align=center>22

normal align=center>20

normal align=center>18

normal align=center>16

normal align=center>14

normal align=center>12

normal align=center>10

normal align=center>全铁（以Fe2O3计）质量分数% ≤

normal align=center>15

normal align=center>氧化钙（以CaO计）质量分数%≤

normal align=center>8

normal align=center>氧化镁（以MgO计）质量分数%≤

normal align=center>45

normal align=center>        矿石块度mm        ＜

normal align=center>400（300-400mm的不大于15%，小于20mm的不大于15%）

注：各项成分含量均以干基计