SANTIAGO, April 22 (Reuters) - Miners Rio Tinto and Eramet as well as battery maker LG Energy were among 30 companies that submitted proposals to develop lithium extraction technology for a Chilean salt flat in early stages of exploration, state-run mining body ENAMI said on Monday.

ENAMI last month put out a call for companies to present technology to do pilot tests of lithium extraction techniques at the salt flat known as Salares Altoandinos, which the Chilean government is seeking to develop for lithium mining. (Reporting by Daina Beth Solomon; Editing by Sandra Maler)