Crucible for gold casting
Worldwide, gold is melted in graphite crucibles. And that's a good thing. For most gold alloys, a certain amount of silver is added as an alloying constituent. This silver has the property to store large amounts of elemental oxygen. This reacts with melting with the graphite of the crucible. The metal is thus freed of oxygen in a redox reaction. If this reaction did not take place, it might lead to gas porosity in the finished casting. Our crucibles should therefore only be used for very high-carat gold with the lowest possible silver content. There, however, they also have their authorization. Since the silver is missing in the alloy, there is no oxygen left to absorb the excess carbon of the crucible. Thus, a graphite-free quality of the crucibles is required for a better casting result without carbon contamination
Iron / steel / stainless steel
In large quantities, graphite crucibles can be easily used in iron and steel production. The resulting slag is simply separated from the desired metal.
In smaller units such as in the jewelry industry or in medical technology, this is not practical. Here it is absolutely necessary to avoid the use of graphite crucibles. Our crucible qualities developed for steel casting can be specially adjusted to individual stainless steels. For this purpose, both the composition of the crucible base material and that of the crucible coating are adjusted accordingly. Thus, it can be ensured that no exchange / transition of alloying constituents of the steel takes place between the steel and the crucible. For some special steel special alloys we can produce such crucibles. However, with the vast majority of steels processed on the market, our standard quality is easily enough.
Graphite is not the same graphite. It differs in grain structure, in density and porosity, in the adhesive used, in the composition, in the degrees of purity ...
Due to our many years of worldwide presence, we have succeeded in finding a company that produces high quality graphite at acceptable prices. The widest variety of crucible types and closure rods can be produced.