Induction-heated quartz tube furnace (IWQ)
Quartz tube furnace for high-purity and aggressive atmospheres for the production of high-purity materials

Features of the IWQ system:

• Inert, highly corrosion-resistant vacuum chamber made of quartz glass with a high degree of axial and radial temperature uniformity
• Induction coil isolated from the vacuum chamber allows the production of high-purity materials
• Excellent resistance to aggressive vapours

Production process in perfectly coordinated system steps

The IWQ systems are available in individual size ranges, depending on the material and atmosphere utilisation, as well as the customer-specific vacuum pump unit. They are used primarily when the feed materials have to be isolated from the heating elements in special high-temperature processes. Specific examples of applications for the IWQ systems include:

• Distillation of metals and alloys
• Melting for degassing, casting or alloying
• Metal production by reduction of metal oxides
• Refinement of optical coating materials, optical fibre materials, high-purity semiconductor materials
• Heat treatment and sintering of ceramics and glass
• Production of rare earth metal compounds such as Sm, Y and UAl4
• Crystal growing of monocrystalline silicon carbide
• Recycling of batteries containing Al, Li, Ni and Cd

Description of the process using the example of vacuum thermal recycling of nickel-cadmium batteries:

The already opened batteries are placed in a steel crucible from above into the vacuum chamber. After closing the lid, vacuum is applied and the steel crucible/susceptor is heated by means of the induction coil.
Now, first the moisture, then the volatile hydrocarbons and finally the highly toxic cadmium are gradually expelled from the batteries.
A pipe inside the crucible conducts the vapours down into a temperature-controlled condenser in which the cadmium is deposited (~99.95% purity).
The remaining battery casings are now free of cadmium and can be recycled as high-quality steel scrap.