Recovery of germanium by chlorinated distillation of high content germanium materials enhanced by ultrasonic external field and arsenic removal

Abstract

Chlorinated distillation is widely recognized as the primary technique for the separation and extraction of germanium from germanium-containing materials. However, challenges such as suboptimal extraction efficiency and the removal of arsenic impurities necessitate further investigation. The integration of ultrasonic external field enhancement technology, commonly referred to as ultrasonic field-enhanced distillation, into the chlorinated distillation process is expected to accelerate metal extraction and improve recovery rates. This research presents findings on the application of ultrasonic external field intensification in the chlorinated distillation of high-content germanium materials (HCGM). At an initial acidity of 9 mol·L⁻¹, the addition of 0.25 g·g⁻¹ of NaOCl, a liquid-to-solid ratio of 7 mL·g⁻¹, and an ultrasonic power of 350 W resulted in a germanium evaporation rate of 96.53 % and an arsenic residual rate of 94.57 %. These rates represent improvements of 5.78 % and 8.28 %, respectively, compared to the conventional process. These enhancements were primarily attributed to the cavitation effects of ultrasound, which facilitate the detachment of inclusions from the material and improve the interaction between the oxidant and the material. This process effectively removes the harmful impurity arsenic from the residual liquid, enabling the selective separation of arsenic while efficiently extracting germanium. The byproduct of the reaction is high-grade lead slag, which can be reintegrated into the lead smelting process for recycling. The resulting high-purity germanium material has undergone treatment that renders it both harmless and resource-efficient.