Exploring High-Resolution Chemical Distribution Maps of Incompatible and Scarce Metals in a Nepheline Syenite from the Massif of “Serra de Monchique” (Portugal, Iberian Peninsula)

In this case study, 2D micro energy dispersive X-ray fluorescence (µ-EDXRF) surveys were performed in the nepheline syenite (NS) of “Serra de Monchique” located southwest region Portugal (Algarve, Iberian Peninsula). The results allow identification mineral matrix certain elements classified as critical raw materials (CRMs). Due to substitution effects, some scarce transition elements, such Zn and Ni, are present camouflaged alkali silicate minerals, while others, Co, included ferromagnesian phases. As expected, incompatible preferably distributed on surface aluminosilicate phases Rb Ga, or exclusively K-bearing feldspar phases, it is Sr. Interesting CRMs Ti, Zr, Nb well individualized oxides, sphene apatite. detected antagonistic chemical distribution between Ti Fe, good spatial relation Ca confirms that and, areas with absent Si, probably occurs rutile. has a pattern quite similar Zr due effects. It was possible conclude there probable co-existence Zr-REE-Nb specific apatite, zircon, other Zr-oxides. These evidence confirm NS potential source multiple industrial minerals distinct which incorporated oxide phosphate can be more effectively separated beneficiation process.