Synthesis of Zirconia from Nigerian Zircon: Integrating Radiological Assessment, Mineral Separation, and Chemical Decomposition

Abstract

Nigeria has significant zircon mineral deposits, but remains a marginal global supplier due to limited beneficiation capacity. This work aims to process zirconia from Nigerian zircon using radiological assessment, chemical decomposition, electromagnetic, and heavy liquid separation. Five zircon samples (A–E) were obtained and identified under a binocular microscope. Brownish, translucent to light yellowish colors, and prismatic shapes confirm zircon grains in the samples. Radiological measurements and EDXRF analysis identified Sample D as optimal, with the lowest dose rate at 2.40 µSv/h, a thoron/radon ratio of 1.05, and the highest zirconia (ZrO2) content at 49.06 wt.%. The beneficiation process recovered 98% of non-magnetic minerals and 99% of heavy minerals. Alkali fusion then yielded zirconia with an 88% extraction efficiency; EDXRF confirmed zirconia purity increased to 91.76 wt.%, and XRD identified monoclinic zirconia as the main phase. Importantly, the synthesized zirconia’s dose rate decreased to 0.29 µSv/h, much lower than the public safety standard of 2.28 µSv/h. This research shows Nigerian zircon as a viable raw material for high-purity zirconia processing, supporting usage in ceramics, nuclear, refractories, and dental applications. The study also contributes to Nigeria's sustainable utilization of zircon mineral resources for value addition.