The Silver Vat is a machine added by Witchery. It is used to gather Silver. Silver Vats can be placed adjacent to Furnaces, and, when Gold Ore is smelted, can obtain the Silver Deposits that are created as a byproduct. The Deposits can be obtained by right-clicking on the vat.
Multiple vats can be placed adjacent to furnaces, and multiple furnaces can be placed adjacent to vats.
It can be automated with the use of Hoppers, or Pipes from other mods.