Is there any knowledge about chemistry in China's classics?

A. replacing copper with iron belongs to wet copper smelting, and a replacement reaction occurred in this process, so a is correct;

B. The blade is hard, so carbon-iron alloy is used, so B is correct;

C. It burns like hemp, but the smoke is very thick, which means it is easy to burn. It should be oil, so C is correct;

D. Extraction is based on the different solubility of solute in different solvents, and there is no liquid stratification, so it is not extraction, so D is wrong.

So choose D.