Guelb el Rhein (Guelbs) is a medium sized surface mine in the Tiris-Zemmour District of northern Mauritania. The mine is owned and operated by the majority state-owned mining company SNIM. Due to its low raw ore grade of 36.5% Fe, the process of mining and beneficiating required for Guelbs raw ore has resulted in a low mass recovery of around 42%. In combination with its strip ratio of 2.8:1, this has resulted in high mining costs. However, the Guelb el Rhein deposit is SNIM's largest deposit and is required to produce sufficient concentrate for blending with ore from its other lower grade mines.