Platinum equipment, handling

The principal applications of the outstanding stability of platinum and its alloys at high temperatures lie in their use as materials of construction for equipment to handle molten glass and as electrical resistance windings for high-temperature furnaces. 

Of very corrosion-resistant materials we have metals such as tantalum and zirconium (both resistant due to passivity), and platinum (immune, passive in strongly oxidizing environment) (see the Pourbaix diagrams for tantalum and platinum in Figure 3.11). Tantalum is attacked by some alkaline solutions, fluoric acid and hot, concentrated sulphuric acid. The metal is used, e.g. for repair of glass-lined equipment and for handling of pure chemicals. Zirconium is used in nuclear... 

Finally, zirconium is an excellent material for laboratory equipment, such as crucibles and autoclaves. Zirconium crucibles have replaced platinum crucibles for handling certain molten salts. Properly oxidized zirconium and zircaloys can be used as insulating washers and measuring devices exposed to high-temperature corrosives. 

---