The following uses for technetium are gathered from a number of sources as well as from anecdotal comments. I'd be delighted to receive corrections as well as additional referenced uses (please use the feedback mechanism to add uses).
- ammonium pertechnate, NH4TcO4, is a specialist corrosion inhibitor for steel. Mild carbon steels are protected by 5 ppm of KTcO4 in aerated distilled water at temperatures up to 250°C. This corrosion protection is limited to closed systems, since technetium is radioactive
- superconductor at 11 K and below
- medical imaging agents
- 95Tc is used for tracer work (radioactive tracers)