Linked from
The 15 pages that link to Smelting, each with the reason it gives.
ReductionRelated: Smelting reduces metal compounds to produce elemental metals.
MetalRelated: Smelting made abundant metal-bearing ores usable as sources of workable material.
BlacksmithingRelated: Iron production supplies the material that blacksmiths shape.
StibniteRelated: Smelting is one route for recovering antimony from processed stibnite.