EXPLORING ROCK PHOSPHATES USING HYPERSPECTRAL REMOTE SENSING & FIELD SPECTROSCOPY

Rock Phosphate (RP) is an important mineral resource with direct utility in the manufacture of phosphate fertilizers, pharmaceuticals, and animal feeds. RP is also one of the major sources of Rare Earth Elements (REE) and radionuclides. Due to efficient (100%) and easy recovery of REEs, RP is gaining importance as an extraordinary source of REE. Conventional techniques such as rapid ammonium molybdate nitric acid field method and portable., handheld X-ray Fluorescence spectrometer which are being used to explore phosphate (P2O5) content are cumbersome and time consuming. In this paper, for the first time, a new spectroscopy based approach relating P-O molecular vibration combinations centered around 2375 rim (2v(3) + 2v(4)) and 2440nm (2v(1) + 3v(3) + 2v(4)) are used to quantify the P2O5 content. Based on the strong, positive correlation (R-2 = 0.97 at 98% significance) between the P2O5 content and spectral absorption depths, four different ore grades of RP namely Low (< 25% P2O5), Medium (25-30% P2O5), high (30-35% P2O5) and Very high (>35% P2O5) could be identified and mapped using hyperspectral data, The proposed methodology is very effective and can be adopted easily.