Pure Graphite Crucible Cup Propane Torch Melting Gold Silver Copper Metal (60x60mm) Important note:Pure graphite crucible can NOT be heating by Carbon furnace or charcoal kiln.Or it will be Oxidized and broken.Material:High purity fine particle graphite Well thermal stability : according to the using conditions of graphite crucible snap heat and cold; Well corrosion resistance, impact resistance performance, to ensure the reliability of product quality; Well resistance to strong acid, strong alkali; Good heat transfer performance of graphite crucible: for greatly shorten the melting time and save energy; Ash content less than 0.1% , to ensure the precious metals in smelting is not contaminated; In high-temperature using process, it got small thermal expansion coefficient;