Smelting lead

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Hut lead (also known as soft lead or hut soft lead hereinafter) is made of lead bullion refined lead with standardized lead contents.

The outdated DIN 1719 standardizes purities of 99.9%, 99.94% and 99.97% lead. The designations are still widespread, as the following standard DIN EN 12659 does not offer any terms.

Composition according to DIN 1719 (max.% Figures)
Type WKSTNr. Ag As Bi Cu Fe Sb Sn Zn
Pb99.9 2.3040 0.1 0.005 0.09 0.005 0.001 0.001 0.001 0.001
Pb99.94 2.3030 0.003 0.001 0.05 0.001 0.001 0.001 0.001 0.001
Pb99.97 2.3025 0.003 0.001 0.027 0.001 0.001 0.001 0.001 0.001

For many technical applications and as a starting material for lead alloys, metallurgical lead is sufficiently pure. For example, pure soft lead alloyed with 2.5% tin is used to manufacture projectiles .

In the case of mechanical stress, the impurities even have a beneficial effect, as they increase the hardness of the material. In particular, metallurgical lead can be used when a low bismuth content is not required.

Lead types of even higher purity are the fine lead (99.985% or 99.99% lead content) and the test lead (e.g. 99.999% Pb). Types of lower purity are the already mentioned lead and remelted lead.

Copper lead with a lead content of 99.94% and approx. 0.03% copper can be distinguished from metallurgical lead despite the comparable lead content, since this is already an alloy close to the eutectic with higher strength.