Japan’s JX Nippon Mining & Metals plans to boost annual copper output at its Caserones mine in Chile by 13% in the next three years, aiming to book an annual net profit by 2022/23, its president Seiichi Murayama said.

The Japanese miner and smelter, owned by Eneos Holdings , which was formerly known as JXTG Holdings, is also looking to invest in rare metal mines, Murayama told reporters on Tuesday.

“We plan to spend 15 billion yen ($140 million) in the development of rare metals in the next three years,” he said, although he declined to say which metals the company is targeting. JX bought a German maker of tantalum and niobium products in 2018.

Under a three-year business plan that started in April, JX plans to increase Caserones’ annual copper output to 171,000 tonnes in the year to March 2023, from 152,000 tonnes in the year ended in March this year.

JX in late March cut operations at the mine by 40% to comply with government measures to limit the spread of the coronavirus.

Caserones began producing copper in the arid mountains of northern Chile in 2014 but the cost of the project doubled to $4.2 billion due to factors including spiking labour costs, bad weather and technical glitches.

A series of ramp-up delays and weaker copper prices forced JX to post about $2.6 billion in impairment losses by March 2018. JX has a 51.5 percent stake in Caserones, while Mitsui Mining and Smelting Co Ltd and Mitsui & Co own the rest.

($1 = 107.2500 yen)

(By Yuka Obayashi; Editing by Richard Pullin)