Articles

Germanium Processing from Primary and Secondary Resources: Occurrence, Extraction Technologies, and Circular Economy Perspectives

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Germanium is a critical technology metal used in fiber optics, infrared optics, photovoltaics, semiconductors, and emerging energy systems. Despite its strategic importance, primary germanium resources are limited, and global production remains heavily dependent on by-product recovery from zinc processing, coal fly ash, and copper-related residues. This review critically examines the occurrence, mineralogy, and distribution of germanium in both primary and secondary resources, emphasizing the growing importance of urban mining and industrial waste valorization. Current recovery technologies are analyzed, including pyrometallurgical, hydrometallurgical, chlorination, volatilization, solvent extraction, ion exchange, and biohydrometallurgical routes. Particular attention is given to the efficiency of selective separation, impurity behavior, energy demand, environmental constraints, process integration, and scale-up limitations. The review highlights that germanium dissolution is often less challenging than downstream purification and selective recovery from chemically complex, highly dilute process streams. Major technological barriers include ultra-low Ge concentrations, impurity-rich matrices, solvent degradation, reagent consumption, and the limited industrial maturity of several emerging recovery technologies. Recent advances in secondary recovery from electronic waste, coal-derived residues, and metallurgical by-products are critically evaluated within the broader context of circular economy strategies and integrated multi-metal recovery systems. The analysis indicates that future germanium supply will depend less on primary mining expansion and more on the ability to selectively recover Ge from complex secondary resources through integrated, economically robust processing systems.

Solid Waste Management and Material Recovery Facility Planning in Leh-Ladakh, Western Himalaya

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Rapid urbanization, tourism growth, and changing consumption patterns have significantly increased solid waste generation in Leh Ladakh, a high-altitude cold desert region of India. This study examines the existing status of waste generation, segregation, and disposal practices in Leh, the largest town in Ladakh, and assesses the feasibility of establishing a Material Recovery Facility (MRF). Field-based inventory, secondary datasets, and the Solid Waste Management (SWM) Manual 2016 were used to estimate waste quantities and design MRF requirements. Results indicate that Leh generates approximately 13.02 tonnes per day (TPD) of solid waste, with 80% comprising dry waste and 20% wet waste. The dry fraction includes paper and cardboard (30%), tetra packs (20%), textiles (17%), PET (8%), and multilayer plastics (7%). Currently, segregation and limited recycling occur at a municipal facility powered by solar energy. However, the absence of a formal MRF, shortage of equipment, and lack of skilled manpower remain key challenges. The study proposes a manual MRF model suitable for <15 TPD, with an estimated operational cost of Rupees 3.06 lakh per annum. Establishing such a facility would improve recycling efficiency, reduce environmental risks, and promote sustainable waste management in this ecologically fragile Himalayan region.