How was mercury removed from silver amalgam in the patio process?

In the patio process, once the silver had dissolved into the mercury to form an amalgam, the mixture was separated from the remaining mud by agitation with water in large tubs. The collected amalgam was then heated to drive off the mercury, effectively isolating the silver. This process of heating the amalgam to distill off the mercury is a standard metallurgical technique used to recover the metal for reuse.12