CRYSTALLISATION PATHWAYS, PROCESS OPTIMISATION AND PRODUCT QUALITY OF INDIGENOUS POTASH/TRONA FROM YOBE STATE: PROSPECTS FOR OILFIELD APPLICATIONS

Yobe State in northeastern Nigeria contains indigenous potash and trona resources with potential as locally sourced alkaline mineral feedstocks for petroleum applications, including drilling fluids, enhanced oil recovery (EOR) and produced-water treatment. However, materials locally described as kanwa, potash or trona are chemically and mineralogically heterogeneous; therefore, feed-specific characterisation is essential before process design. This review examines crystallisation pathways for Yobe potash/trona using a composition-driven resource–process–product framework. It discusses the conversion of heterogeneous raw materials into defined crystallisation liquors through dissolution, clarification and targeted pretreatment, and evaluates evaporative, cooling, fractional/polythermal, recrystallisation, seeded and hybrid crystallisation routes. Particular attention is given to mixed Na–K feedstocks, for which fractional crystallisation may enable sequential recovery of Na- and K-rich products, although Yobe-specific solid–liquid equilibrium and kinetic data remain limited. Product quality is assessed in terms of composition, phase purity, physical characteristics, stability, impurity control and application-specific requirements. The review links processing intensity to product specification and oilfield suitability, emphasising the need for rigorous qualification against petroleum-industry requirements. Priority areas for future work include Yobe-specific phase-equilibrium and kinetic studies, selective Na/K recovery, product validation, pilot-scale development and techno-economic assessment.