A review of metallurgical processing and value-added utilization strategies for zinc oxide

Zinc oxide is a critical industrial material with extensive applications in galvanization, ceramics, electronics, and renewable energy systems. Despite China's vast zinc reserves (41 million tons), domestic production of primary zinc oxide from concentrates remains limited to 20%, with recycled materials contributing merely 11%. As a result, there is a heavy reliance on imported resources. This imbalance underscores the urgent need to optimize the utilization of secondary resources and adopt sustainable technologies. This review systematically examines recent advancements in zinc oxide smelting, enrichment, analytical characterization, and strategies for a circular economy. Modern hydrometallurgical techniques, such as high-temperature acid leaching and ammonia-ammonium carbonate systems, have achieved over 95% zinc recovery from low-grade ores. Innovations in pyrometallurgy, including microwave-assisted reduction and rotary kiln volatilization, have reduced energy consumption by approximately 30% while minimizing emissions. Advanced detection methods, such as X-ray fluorescence spectroscopy and combustion furnace-ion chromatography, enable precise monitoring of toxic elements, including lead, cadmium, and arsenic. Furthermore, circular economy approaches-such as slag geopolymerization and nano zinc oxide synthesis from industrial by-products demonstrate significant potential for waste valorization. By integrating interdisciplinary technologies, such as machine learning and biohydrometallurgy, this review outlines a potential roadmap toward a sustainable zinc industry, balancing economic growth with environmental responsibility.