What happens to the dicalcium silicate slag made during thermal magnesium production?

In the context of thermal magnesium production, the dicalcium silicate slag is handled differently depending on the specific industrial process used:

• Pidgeon Process: Because the reaction occurs at 1,200 °C, the dicalcium silicate slag remains in a solid state and is evacuated from the retorts as a solid after the reaction cycle is complete.1
• Magnetherm Process: By adding alumina to the charge, the melting point of the slag is lowered to 1,550–1,600 °C. This allows the slag to remain in a liquid state, which is then tapped from the reactor at intervals.1

In both cases, the management of the slag is a necessary step in the extraction process to allow for the continued operation of the furnaces and retorts.1