Melting furnace constructions

Melting furnace constructions for the melting of ingots, the constructions including crucibles and insulating means for the crucibles. The insulating means serve to separate the charge from the heating means for the construction. The ingots employed are maintained out of contact with the crucible side walls and the crucibles define bottom surfaces which include means for maintaining substantial portions of the ingot bottoms out of contact with the crucible bottom. This arrangement minimizes heat exchange between the charge and the crucible to minimize thermal shock. The crucible is also preferably provided with a capsule of ceramic material cast around the crucible. The capsule and crucible combination is inserted within a liner with the adjacent capsule and liner surfaces substantially conforming whereby ideal support and strength for the combination is accomplished.