In the large scale production of lead and other metals and alloys, ingots are a standard way to form the metal into an easy to handle and work with shape and size. Depending on the industry, ingots can be relatively small bars or they can extremely heavy blocks of metal that are used in industrial processing and manufacturing.
The manufacturing or processing of the ingot is just one factor in the size. The other is often the cost of the alloy with the higher cost types of metals typically being produced in smaller ingots. For example, you wouldn’t expect to find the same size of bar used in casting lead ingots and casting gold bars. However, the process will be virtually identical.
Mining
Lead is a natural material, which means that it is found in the earth and harvested through mining processes. Typically, this raw lead is combined with deposits of zinc, copper, and silver. Galena is the raw material, which contains approximately 86% lead.
During processing, the raw material is ground and mixed with water, chemicals, and air to separate the various components. The lead is then melted to remove impurities through a refining process.
Approximately half of all lead used today in casting lead ingots is recycled. Top companies are careful in recycling to eliminate other alloys and retain the specific quality of the ingots produced.
The Process
The process of casting lead ingots has not changed dramatically over time, other than to become automated and on a much larger scale. The lead is heated to the point of being molten, then poured into molds and cooled rapidly.
This cooling process is done specifically to create the physical characteristics required by lead in further processing. It is then ejected from the mold when cooled, and the ingots are moved along the production line for further surface processing if required.
