[Back]

C. Edtmaier, P Svec:
"The role of reactions between crucible and melt during refining of platinum by vacuum induction melting";
Canadian Metallurgical Quarterly, 43 (2004), 3; 371 - 380.

Secondary platinum and Pt alloys can be purified by the selective evaporation of undesirable elements in a vacuum induction melting process. Investigations were made concerning reactions among four different crucible materials and the melt of pure platinum. Relations between the vacuum evaporation of copper, iron, antimony and aluminum additions in a platinum melt and the used crucible were also studied. Minimum enrichments and reactions between the melt and the crucible material are the aim for industrial purposes. The requirements concerning the iron concentration in the cast and resulting devices are especially high. Experimental results show that there can be a marked reaction between the crucibles and the pure Pt melt depending on time, applied atmosphere and the crucible material used. Refining experiments showed that it is possible to reduce the concentration of some elements clearly below 10 ppm, although the complete removal of iron is almost impossible. The refining behaviour can generally be attributed to the nominal composition of the used crucibles, its reactions with the melt and the applied atmosphere.

http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC04969153