Physicochemical Properties and Beneficiation Challenges of Valleriite: A review

Driven by the rapid advancement of wind, solar, and electric vehicle technologies, global copper demand has increased significantly, prompting greater attention to complex and refractory copper-bearing minerals. Valleriite is a representative example, widely distributed in Cu–Ni sulfide ores and regarded as the second most important copper-bearing phase after chalcopyrite. Structurally, valleriite features a layered crystal lattice composed of alternating hydrophobic sulfide and hydrophilic hydroxide layers, giving it characteristics intermediate between sulfide and oxide ores. This unique structure—combined with its fine grain size, poor crystallinity, and complex intergrowths—greatly limits the efficiency of conventional beneficiation methods such as flotation and magnetic separation. This review systematically summarizes the global distribution and physicochemical properties of valleriite and critically assesses beneficiation studies reported over the past seven decades. Furthermore, the key factors contributing to its poor recovery are identified, and potential strategies for improving valleriite-bearing ores are proposed.