Foundry

The Foundry is an early-settlement production building which allows the smelting of Ores into their pure metallic form, like Copper or Silver. Due to the vital role of metals in advancing to new eras, unlocking the Foundry is often considered the most important earlygame milestone aside from Agriculture.

All metals require further crafting from a Tool Maker, Weapon Maker or Jewelry Maker to convert them into useful goods like Axes, Spears or Jewelry (Resource). As you progress in knowledge, metal processing at these buildings typically unlocks in the following order: Copper > Bronze > Iron > Steel.

Production
Certain recipes require smelting at much higher temperatures and won't be visible on the recipe list until you unlock them:

Steel production requires processing of smelted Iron at a separate building, the Steel Mill.

Conversion Table
The following table shows how many Ore tiles are required for Mining Camps to support a production rate of 1.0 Bars per tick at the Foundry. During smelting, production may pause if you have less than 0.1 Bars worth of resources available (Gold in particular tends to have this issue at less than 16 Ore tiles).