There was only a single word of difference between elixir and weapon refinement on the surface, but in reality, there was a huge difference.
Weapon refinement required a high level of spirit fire.
The higher the level of spirit fire, the higher the efficiency and outcome of the smelting process where impurities were purged.
However, it was different for elixir refinement.
Elixir refinement placed a huge emphasis on the mastery of spirit fire.
That was because spirit herbs were different from the materials used for weapons and they had a low burning point. Even a Level 1 Spirit Fire could refine most of the spirit herbs.
In elixir refinement, there were two extraction processes which required a precise mastery of the spirit fire's temperature.
If the temperature was too high, the spirit herbs would be burned to a crisp.
If it was too low, one would not be able to extract the essences of the spirit herbs.