Final answer:
Copper was the first metal to be smelted from its ore, dating back to around 5000 BC. This was made possible due to copper's presence in directly usable metallic forms in nature and precedes the smelting of other metals like iron and aluminum, which required more advanced techniques.
Step-by-step explanation:
The first metal to be freed from its ore by smelting was copper. Copper is known to have been smelted from sulfide ores as early as 5000 BC, making it the earliest known metal to be obtained from its ore through the process of smelting. The significance of copper in ancient history is highlighted by the fact that it was the first metal to be cast into a shape in a mold and the first to be purposefully alloyed with another metal, tin, to create bronze.
Isolation of copper initially involved roasting copper sulfide ores to remove sulfur as sulfur dioxide before further processing. The smelting process for copper involved heating the sulfide ore along with a reducing agent, such as charcoal or later coke.
In contrast, aluminum wasn't isolated by smelting due to the high temperatures required for reduction. Instead, aluminum started to be obtained by a different process known as electrolysis after the invention of the Hall-Héroult process in 1886. Iron smelting came much later in human history due to the more complex process required to reduce iron from its naturally occurring oxidized forms.