浮遊 ふゆう選鉱 せんこう ほうじゃなかったです
fuyūsenkōhōjanakattadesu

Noun
Desu Copula

The polite, past negative form of 浮遊選鉱法

1. Flotation wasn't used.; It wasn't flotation.

Past/Perfective
Negative
Polite
Casual Register