12″ GOLD ORE SMELTING KIT FURNACE

As soon as the crucible has reached the specified pre-heat temperature, charge and melt immediately. Charge light scrap and returns first in order to form a cushion for heavier material. Use tongs to charge ingots and place large pieces and ingots vertically allowing space for expansion. Only add
flux once the metal is molten.

A new crucible should initially be heated slowly and evenly to 600ºC on low power, avoiding local impingement of flame. Subsequently the full heat input rate should be utilised to achieve a uniform bright red condition over the whole crucible (circa 900ºC / 1650ºF) at which point the crucible
should be charged immediately taking care to avoid packing metal tightly or bridging ingots across the crucible. The furnace controls can then be set to achieve the desired metal operating temperature and heating should continue at the full rate until the metal has reached the desired temperature.
In the case of crucibles to be fed with molten metal, it is important that the crucible body temperature is equivalent to or slightly above that of the molten metal in order to minimise thermal stress.