She had also used this method to soften natural copper, but it couldn't raise the melting point to turn copper into molten copper.
Everyone knew that charcoal could be obtained by burning wood.
The advantage of charcoal is that it easily crumbles; the method is to burn the wood into charcoal, then smash it with stones, gather it up, and thus have fuel for burning even in winter.
But burning charcoal was also a skillful task, requiring timely exclusion of air, or it would turn into ash.
Tangtang filled charcoal into the furnace, lit it, placed the broken up ore on top, ignited it, but using beast skin or large leaves to fuel the fire was too tiring, so Tangtang used her brains and had them make her a bellows. With this, the ore was easily reduced by the charcoal to obtain copper.
Although she conducted many experiments, there weren't systematic steps involved; in the end, Liang Tian couldn't bear to watch and gave her some tips.
