Integrated Co-Valorization of Phosphate and Oil Shale Resources: A Circular Economy Strategy for the Al Abiad Region, Central Jordan

Abstract

High overburden-to-ore ratios and complex lithostratigraphic heterogeneity increasingly limit the economic viability of sedimentary phosphate deposits. This study evaluates the techno-economic prefeasibility of shifting from a traditional single-commodity extraction to an integrated dual-commodity strategy at the Al Abiad deposit. Geological characterization shows a clear inverse spatial relationship between the primary phosphate horizons and the overlying bituminous marls (oil shale), creating rigid boundaries that challenge traditional mine planning. The assessment shows that a single-commodity approach yields a prohibitive average Stripping Ratio (SR) of 10.7:1. In contrast, the proposed dual-extraction strategy reclassifies the oil shale from waste to ore, capturing an additional 21.99 million m 3 of energy resources and reducing the effective SR by approximately 44% to a sustainable 6.0:1. To address the valuation challenge of the non-traded oil shale, a Netback Electricity Pricing Model (NEPM) was developed, deriving the resource’s intrinsic value from regulated electricity tariffs rather than standard fossil fuel benchmarks. The analysis identifies a break-even electricity tariff of US $0.122/kWh, below which the resource has no economic value. Under current tariff structures, the co-extraction model is projected to increase net income by 19% to 28.7% compared to the baseline. These findings confirm the integrated mining model as a robust approach to reducing resource sterilization, mitigating market volatility, and advancing circular economy principles in the extractive industries.