Short answers, pulled from the story.
Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, known as alloys. A specialist practitioner is called a metallurgist. It is distinct from the craft of metalworking, which it provides with a scientific foundation.
Chemical metallurgy concerns the reduction and oxidation of metals and their chemical performance, covering mineral processing, extraction, thermodynamics, electrochemistry, and corrosion. Physical metallurgy focuses on the mechanical and physical properties of metals, including crystallography, material characterization, phase transformations, and failure mechanisms.
The earliest metal used by humans appears to be gold, which can be found native. Small amounts of natural gold dating to the late Paleolithic period, around 40,000 BCE, have been found in Spanish caves.
The first evidence of copper smelting, dating from the 6th millennium BCE, has been found at Majdanpek, Jarmovac, and Pločnik in present-day Serbia. The site of Pločnik produced a smelted copper axe dating from 5,500 BCE, belonging to the Vinča culture.
Wootz steel, also called Golconda steel, is an ultra-high carbon steel developed in the Indian subcontinent as early as 300 BCE, with a natural inclusion of carbide-forming vanadium at around 0.005%. It was exported from the Chera dynasty and called Seric Iron in Rome and later known as Damascus steel in Europe.
Georg Agricola has been described as the father of metallurgy. His 16th century book De re metallica describes the highly developed and complex processes of mining metal ores, metal extraction, and metallurgy of the time.
The production of ferrous metals accounts for 95% of world metal production. Ferrous metallurgy, also known as black metallurgy, involves processes and alloys based on iron, while non-ferrous metallurgy covers other metals.