... thermal insulation Graphite crucible:1. The graphite crucible is the smelting appliances of the non-ferrous metal and rare metal used ... -burning graphite clay pot is mainly used for the nonferrous smelting of copper, aluminum, alloy, etc.3. The resistance furnace highly ... pure graphite crucible is mainly used for the smelting of gold, silver, and rare metal. The ceramiccrucible is ...