Mineralogical Characterization of Azara (Nigeria) Barite Ore

The aim of this study is to characterize barite samples from Azara located in Nasarawa state, Nigeria, and determine their suitability for oil and gas applications. The mineralogy, chemical composition, morphology and specific gravity were determined using X-ray diffractometry, X-ray fluorescence (XRF), scanning electron microscope and energy-dispersive X-ray and optical microscope. Particle size analysis was done using wet sieve analysis and heavy liquid separation; lastly, a pycnometer was used to determine the specific gravity (SG). The results of the chemical composition by XRF revealed the presence of BaO, Fe2O3, SiO2, SO3 and SrO, while the minor minerals present were MgO, Al2O3, K2O, CaO, MnO and NaO and the trace minerals found were P2O5, Cl, NiO, CuO, ZnO and PbO and mineralogical analysis by X-ray diffractometry revealed the presence of 83% barite, 4% quartz and 14% siderite from the head sample. Wet sieve analysis showed that at −600 + 300-µm- and −150 + 75-µm-sieve size, the SG was slightly above 4.2 g/cm3 meeting the API requirements. The results obtained from the heavy liquid separation (HLS) using TBE (2.95 g/cm3) indicated that mineral liberation occurs at (−600 + 300 µm and −300 + 150 µm), with specific gravities of 4.35 g/cm3 and 4.48 g/cm3, respectively. In the sink fraction (−300 + 150 µm) of the HLS, there were 82% barite, 2% quartz and 17% siderite, while in the float fraction 9% barite, 64% quartz, 2% siderite, 12% feldspar and 14% microcline were found. The results indicate that Azara barite ore meets up with the API requirement for drilling mud and has provided relevant mineralogical information to be used to design mineral processing.