The miner expects to invest 525 million euros in the Centenario deposit with the aim of producing 24,000 tonnes of lithium carbonate equivalent per year.
GDP growth in the DRC is expected to fall to 4.3% this year from 5.8% in 2018, due to a slowdown in mining activity triggered mainly by lower cobalt prices.
The importance of rare earths, has been thrust into the spotlight in recent weeks as China mulls whether to use its position as the world’s dominant supplier as a counter in its trade war with Washington.
POSCO's decision is the latest in a string of setbacks for Chile, which has struggled to modernize its lithium policies, boost output and develop a domestic battery industry.