Techno-Economic Performance and Circularity Metrics of Zirconium Processing Technologies: From Zircon Decomposition to Nuclear-Grade Zirconium

Researchers commonly compare zirconium processing routes by extraction yield, separation factor, or individual unit-operation efficiency, even though their economic and environmental significance depends on the final product and the entire sequence of transformation, purification, recycling, and waste management. This critical review develops a harmonized comparison framework for alkaline, chloride, hydrometallurgical, hybrid, electrochemical, and secondary-resource routes from zircon decomposition toward high-purity zirconium intermediates and nuclear-grade products. A structured, non-systematic evidence synthesis of the supplied 2010–2026 bibliography examines system boundaries, closed mass balances, Zr/Hf rejection, reagent and water intensity, energy and carbon accounting, residue burdens, cost architecture, evidence maturity, and uncertainty. The analysis shows why single-stage recovery and laboratory separation factors do not establish flowsheet competitiveness: impurity specifications, scrub and strip losses, recycle performance, salt generation, and scale-dependent utilities determine overall outcomes. We propose an explicit hierarchy of comparable functional units, measured versus modeled metrics, and evidence-gated multicriteria screening. The framework identifies reporting priorities required for credible techno-economic and life-cycle comparisons without extrapolating unverified commercial performance from laboratory data.