The following uses for lanthanum 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).
- rare-earth compounds containing lanthanum are extensively used in carbon lighting applications, especially by the motion picture industry for studio lighting and projection
- 203La improves the alkali resistance of glass, and is used in making special optical glasses
- small amounts as an additive are used to produce nodular cast iron
- hydrogen sponge alloys containing lanthanum reversibly take up to 400 times their own volume of hydrogen gas. Heat is released, therefore these alloys have potential in energy conservation systems
- lighter flints