Highly-insulated ingot mold

An ingot mold for curing fused and melted material, comprising:

• a steel box;
• a non-oxide based insulation material layer;
• a foamed carbon layer;
• and
• a graphite block layer positioned to contact the fused and melted material,
• wherein the ingot mold reduces heat flux to less than about 25% of a heat flux of a standard practice ingot mold lined solely with dense graphite blocks.

A method of producing a fused cast ingot having increased crystal size, the method comprising:

• pouring fused and melted material into an ingot mold, the ingot mold including a steel box, a non-oxide based insulation material layer, a foamed carbon layer, and a graphite block layer;
• and
• allowing the material to cool within the ingot mold,
• wherein the material remains within a crystal growth temperature range for at least about 12 hours following casting.

An ingot mold for curing fused and melted material, comprising:

• a steel box;
• a non-oxide based insulation material layer lining an inner surface of the steel box;
• a foamed carbon layer formed inward of the insulation material layer;
• and
• a graphite block layer formed inward of the foamed carbon layer and positioned to contact the fused and melted material,
• wherein the non-oxide based insulation material has a service temperature of at least about 3000°F,
• wherein a combined thermal resistance of the insulation material layer and the foamed carbon layer is greater than a thermal resistance of the graphite block layer, and
• wherein the ingot mold reduces heat flux to less than about 25% of a heat flux of a standard practice ingot mold lined solely with dense graphite blocks.