Why does silicomanganese production require more energy than ferromanganese production?

Silicomanganese production requires more energy than ferromanganese production primarily because the smelting process for silicomanganese involves higher temperatures and the additional energy-intensive requirement of reducing quartz to silicon.1

While ferromanganese production typically consumes between 2,400 and 3,100 kilowatt-hours per ton depending on the method used, silicomanganese production requires 3,800 to 4,800 kilowatt-hours per ton. This increased power consumption is necessary to facilitate the chemical reduction of silica into silicon, which is then incorporated into the alloy.213