This document discusses types of metallurgy, including ferrous and non-ferrous metallurgy. It focuses on describing the history and processes of ferrous metallurgy, which involves iron. Key points include that the earliest iron artifacts date back to 4000 BC in Egypt and were made from meteoritic iron-nickel. Iron smelting, which is more difficult than other metals, emerged in the Middle East around the 3rd millennium BC. The Iron Age began at different times in different places as the technology spread, starting around 500 BC in Central Europe and India/China between 1200-500 BC. Non-ferrous metals like copper are also recycled due to their extensive use.