Lead Alloy for Copper Smelting Process

[Andika from Indonesia]

What is the use of adding lead alloy in the copper smelting process?

[Frosty]

Welcome aboard Andika, glad to have you. Normally I'd ask you add your general location in the header but seeing as you've put it in your login I won't be redundant. 

A couple points of clarification are necessary and might just be an artefact of a translation program. Lead is an element, not an alloy. Alloys are mixtures of metals though it's often applied to non-metallic additions like Carbon. 

Second "Smelting" is the process of purifying ore into a metal and addition of alloying metals to a smelt is almost never done, at least not in modern metal production.

Lead is a very useful metal and is added to many alloys. In copper it all depends on the end use. It lowers the melting temperature and alters bonding properties in silver or copper solders. It is also added to increase malleability for extruded or pressed copper products. Different % imparts different properties. at a very low % it acts like a lubricant making copper move with less resistance and more fluidly in extrusion dies. at a lower % is makes the copper malleable and pressable. 

It's used to make wire draw more easily with less tool wear and overall power requirements. 

Those are just a few off the top of my head, there must be thousands of things lead can and does do in copper alloys, not to mention so many other metal alloys.

Frosty The Lucky.