Strategies for Recycling of Primary and Secondary Resources for Germanium Extraction

Mechanism of Germanium Adsorption by Iron Hydroxide Colloids during the Leaching Process of Secondary Zinc Oxide

“…When C Me n+ is 1, the pH at hydrolysis equilibrium PH θ is as follows 34 The calculation formula for the equilibrium pH value during Me n+ hydrolysis precipitation can be derived from (7) and (8), as follows…”

“…Typically, the initial step in factories involves the enrichment of germanium found in secondary zinc oxide, which contains 200–800 g/t of germanium. Subsequently, a series of processes including sulfuric acid leaching, tannin precipitation for germanium extraction, chlorination distillation, and other techniques are employed to produce high-quality germanium. − The process flow is illustrated in Figure . In the sulfuric acid leaching process of secondary zinc oxide, it is crucial to maximize the extraction of germanium into the solution to avoid waste or the need for repetitive recovery, which would result in increased costs.…”

Sustainable Production of Ultrathin Ge Freestanding Membranes

“…However, it comes predominantly from new scraps generated during the manufacturing process of fiber-optic cables, infrared optics, and substrates, which are reclaimed and fed back to the production process [15,16]. Although the recycling of old scraps has increased during the past decade, it comes mainly from end-of-life fiber-optic cables and infrared optics, as the Ge recovery from electronic devices is a very complicated process that has not been demonstrated at an industrial scale [17,18]. Indeed, while conventional Ge substrates have a thickness of 140 µm, 225 µm, and 450 µm for diameters of 100 mm, 150 mm, and 200 mm [19], respectively, the efficiently required thickness for device operation generally does not exceed 10 µm.…”