Mining has a long history in Mauritania and Guelb Moghrein is one of the largest external investments in the country. The copper-gold operation is located 250km northeast of the capital, Nouakchott, near the town of Akjoujt. The Guelb Moghrein deposit was first developed in the early 1970s by Anglo American Corporation, however, it closed in 1977 due to technical difficulties and high fuel prices.

First Quantum acquired an 80% interest in the asset in 2004 and achieved commercial production in 2006, increasing its investment through plant upgrades in 2008 and adding a magnetite plant in 2013. In 2010, the Company increased its ownership in Guelb Moghrein to 100%.

Full year 2024 production was about 18,000 tons of copper, 31,000 ounces of gold and 560,000 tons of magnetite in concentrates. MCM has a workforce of 1,200 people,  of which more than 96% are Mauritanian.