Complex sentence: Peritz The smelter, which transforms imported bauxite to alumine and to aluminum by electrolytic process, employed up to 7,500 persons in the 1950s and the 1960s.
Split into simpler sentences: Peritz The smelter, which transforms imported bauxite to alumine, and to aluminum, by electrolytic process. This process, and the smelting plant thereto, employed up to 7,500 people in the 1950s and the 1960s.