Advances and Application of Lead Alloy Anodes for Zinc Electrowinning

Zinc electrowinning operations require anodes that can withstand highly corrosive sulfuric acid electrolyte conditions while maintaining dimensional stability and electrical efficiency over extended service lives. Lead-silver alloy anodes have become the industry standard for zinc electrowinning applications, but significant variations in manufacturing methods, pre-treatment processes, and operational practices affect anode performance and longevity. This technical paper provides a comprehensive comparison of cast versus rolled lead-silver anode manufacturing techniques, examining the metallurgical differences, performance characteristics, and economic considerations relevant to zinc producers worldwide.

The publication analyzes critical factors influencing anode service life, including alloy composition optimization, surface pre-treatment methodologies, and the formation of protective oxide layers that resist corrosion in aggressive electrolyte environments. Different pre-treatment approaches—including electrochemical conditioning, chemical treatments, and controlled oxidation processes—are evaluated for their effectiveness in establishing durable protective surfaces that minimize lead contamination of cathode zinc while extending anode replacement intervals. These operational considerations directly impact production costs, product quality, and environmental management at zinc electrowinning facilities.

Manufacturing process selection between cast and rolled anodes involves trade-offs in initial capital investment, dimensional precision, grain structure uniformity, and mechanical properties. The paper examines how these manufacturing differences translate into operational performance variations, maintenance requirements, and total cost of ownership over the anode lifecycle. Understanding these relationships enables zinc producers to make informed procurement decisions aligned with their specific operational requirements, electrolyte chemistry, and production objectives.

This technical analysis provides valuable guidance for zinc electrowinning operations seeking to optimize anode selection, extend service life, and reduce operating costs. The comprehensive treatment of manufacturing technologies, pre-treatment options, and operational best practices offers practical insights applicable across diverse electrowinning facility configurations and operating conditions.