Phase-tailored hydrometallurgy for sustainable valorization of hazardous beryllium-bearing slag

Abstract

As the primary industrial route for beryllium (Be) production, the magnesiothermic reduction of BeF 2 generates toxic, Be-laden reduction slag, posing severe ecological risks and wasting critical strategic resources. To overcome the prohibitive costs and incomplete recovery of conventional remediation, a phase-tailored hydrometallurgy is proposed. The phase-specific distribution and physical occurrence of Be are unveiled through systematic multi-scale characterization. Initial aqueous leaching quantitatively establishes that 25.6% of the Be in the slag is present as highly soluble BeF 2 , whose selective dissolution thereby facilitates the deep extraction of residual Be via targeted HF leaching. Crucially, the requisite HF concentration is reduced from 18 wt.% to 8 wt.%, and processing duration is condensed from 6 h to 10 min. This parametric optimization yields a 99.1% extraction efficiency while significantly mitigating equipment corrosion and energy consumption. Concurrently, upon further processing, the depleted residue (retaining merely 0.029 wt.% Be) can be valorized as important chemical products. Furthermore, the leachates yield a refined BeF 2 product with 99.8% purity, achieving a 99.3% cumulative recovery. This process offers a highly sustainable strategy for comprehensive Be valorization, contributing to the mitigation of ecological hazards and the loss of critical resources.