Hey there

Metal is a crucial part of our industries band thus we need engineering who can extract them economically and efficiently for that we have metallurgy as a branch in engineering. They study about metals their physical and chemical properties. But one can't say it's a sub stream of chemical engineering. All engineering branches are related like in metallurgy itself we learn thermodynamics and same in mechanical engineering so then these branches will also be similar. But it's not like that chemical engineering is large scale chemist work and thus in making demineralised water to ammonia and etc we need chemical engineering. And for iron ores etc we need metallurgy both have different purposes.

Good luck