The Democratic Republic of Congo (DRC) has joined an emerging club of nations seeking to boost revenues and local employment by banning copper and cobalt concentrate exports in lieu of domestic refinery construction, according to Reuters.

The huge war-torn former Belgian colony is the No. 8 copper producer where production has soared to 600,000 metric tons (mt) from 5,000 mt since 2002. The central African nation is also the world’s top cobalt producer — representing 60,000 of 110,000 mt mined globally in 2012.

The directive, dated April 5 and signed by Mining Minister Martin Kabwelulu, gives companies three months to empty stocks, Reuters reported. “Little by little, we need to no longer export concentrates,” Kabwelulu told the news agency.

This may not be a done deal, however. Kinshasa, according to analysts, introduced similar rules in 2007 and again in 2010—before each decision was reversed; routine power outages and poor infrastructure has factored into the equation. Kabwelulu, meanwhile, said some companies could circumvent the ban via extra payments to the government.

Majors like Freeport McMoRan and Glencore that already process most copper internally will likely be unaffected. Smaller miners like Mawson West and Tiger Resources, on the other hand, are more likely to be impacted.