铜冶炼分银渣是指铜冶炼过程中产生的含银渣，其中含有多种金属元素，如铜、铅、锌等。铅是其中的一种重要元素，其含量的测定对于铜冶炼工艺的控制和优化具有重要意义。本标准规定了铜冶炼分银渣中铅含量的测定方法，采用Na2EDTA滴定法测定。

1.标准适用范围
本标准适用于铜冶炼分银渣中铅含量的测定。

2.仪器设备
2.1 滴定管：容量为25mL，精度为0.1mL。
2.2 滴定管架：可固定滴定管。
2.3 磁力搅拌器：可调速，可控制搅拌速度。
2.4 pH计：精度为0.01。
2.5 称量仪器：精度为0.0001g。

3.试剂
3.1 Na2EDTA：纯度不低于99.5%。
3.2 NH4Cl：纯度不低于99.5%。
3.3 NH4OH：纯度不低于25%。
3.4 硝酸：纯度不低于65%。
3.5 铅标准溶液：浓度为0.1mol/L。

4.样品处理
4.1 取样：将铜冶炼分银渣样品取1g，精确称量。
4.2 溶解：将样品加入100mL三角瓶中，加入10mL浓硝酸，加热至完全溶解，冷却至室温。
4.3 转移：将溶解后的样品转移至250mL容量瓶中，用去离子水定容至刻度线。

5.操作步骤
5.1 取样：取10mL样品溶液，加入50mL三角瓶中。
5.2 加试剂：加入2mL NH4Cl和10mL NH4OH，用去离子水定容至100mL。
5.3 滴定：用0.01mol/L Na2EDTA溶液滴定至pH为5.0左右，记录滴定体积V1。
5.4 加标准溶液：加入10mL铅标准溶液，用去离子水定容至100mL。
5.5 滴定：用0.01mol/L Na2EDTA溶液滴定至pH为5.0左右，记录滴定体积V2。
5.6 计算：计算铅含量C（%），按下式计算：

C（%）=（V2-V1）×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0.1×0