铋精矿是一种重要的金属矿石，其中含有多种金属元素，其中铅是一种常见的杂质元素。铅的含量对铋精矿的品质和应用有很大的影响，因此需要对铅的含量进行准确的测定。本标准规定了两种测定铅量的方法，分别是Na2EDTA滴定法和火焰原子吸收光谱法。

1. Na2EDTA滴定法
1.1 试剂和仪器
1.1.1 试剂
Na2EDTA，氢氧化钠，二氧化锰，硝酸，硫酸，酒精，甲醇，指示剂（二甲基黄），标准铅溶液。
1.1.2 仪器
滴定管，分析天平，电磁搅拌器，pH计，紫外可见分光光度计。
1.2 操作步骤
1.2.1 样品的制备
将铋精矿样品研磨成细粉，取约0.5g样品，加入100ml锰酸钾溶液中，加热至沸腾，保持沸腾10min，冷却后过滤，将滤液定容至100ml。
1.2.2 滴定操作
取10ml样品溶液，加入10ml氢氧化钠溶液，加入适量的二甲基黄指示剂，用0.01mol/L Na2EDTA溶液滴定至溶液颜色由黄色变为无色，记录所用Na2EDTA溶液的体积V1。
1.2.3 标准铅溶液的滴定
取10ml标准铅溶液，按照上述方法进行滴定，记录所用Na2EDTA溶液的体积V2。
1.3 计算
样品中铅的含量（%）=（V1-V2）×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1