Regular Article

Recovery of germanium from acid leach solutions of zinc refinery residue using an oxime extractant of HBL101

¹ School of Materials and Metallurgy, Northeastern University, 110819 Shenyang, PR China
² School of Engineering, Changchun Normal University, 130032 Changchun, PR China
³ Guangdong Province Key Laboratory of Rare Earth Development and Application, Guangdong Province Research Institute of Rare Metals, 510650 Guangzhou, PR China
⁴ School of Metallurgy and Environment, Central South University, 410083 Changsha, PR China

^* e-mail: 105393209@qq.com; yuanzhenxia_1104@aliyun.com

Received: 12 October 2017
Accepted: 2 May 2018

Abstract

An oxime extractant of HBL101 was used to extract germanium from acid leach solutions of zinc refinary residues. The effect of acidity on extraction was investigated. Germanium was extracted from a sulphate acid solution with not too high acidity (1.0∼1.2 mol/L H₂SO₄), while zinc, cadmium, iron, gallium and arsenic were not extracted. Only small amount of copper was co-extracted. The germanium was readily stripped from the loaded organic solution with NaOH solutions. After germanium stripping, the co-extracted copper can be stripped using 2 mol/L H₂SO₄ while the extractant regenerated for recycling. The system was optimised in terms of organic composition and conditions of extraction and stripping and further characterised in terms of extraction and stripping kinetics and distribution isotherms. More than 98.5% of germanium was extracted in five-stage counter current extraction using an organic system of 30% HBL101 and 70% sulphonated kerosene and a feed containing 0.25 g/L Ge and 113 g/L H₂SO₄ with an A/O ratio of 4:1 at 25 °C for 20 min. The loaded organic containing 0.905 g/L Ge was stripped using 3.75 mol/L NaOH solution in five-stage counter current stripping with an A/O ratio of 1:4 at 25 °C for 25 min to selectively strip germanium followed by using 2 mol/L H₂SO₄ to strip co-extracted copper for recycling. The concentration of Ge in strip liquor reached 3.56 g/L.