Reclaiming Ruthenium: A Comprehensive Review of Hydrometallurgical Strategies for Precious Metal Recovery

Ruthenium, a critical metal, plays an increasingly important role in modern applications, such as catalysts for chemical synthesis and the production of hard disk drives. As a result, the supply has struggled to meet the growing demand in recent years. The economic position of ruthenium presents an opportunity to examine the methods of its extraction, particularly given that it is a lesser-known platinum group metal. This article explores the concentration of ruthenium in natural sources and the methods used in primary production, with a particular focus on hydrometallurgical techniques applied at an industrial scale. It also discusses secondary ruthenium-containing materials, including spent catalysts, metallurgical by-products, wastewaters, spent nuclear fuel. The article provides a detailed analysis of the composition of these materials, emphasizing hydrometallurgical methods like leaching and separation processes, along with the recovery of final products.