The deepest mine in the world is the Mponeng Gold Mine southwest of Johannesburg in South Africa. The operating depth averages between 2.8km to 3.4km. That would be about 1.7 to 2.1 miles.
Actually, Eight of the worlds’ 10 deepest mines in the world are in South Africa The others are in Ontario, Canada. The South African ones produce gold. The Canadian wones produce nickle (Creighton) or copper and zinc (Kid Creek).