Process Development For The Eskay Creek Project

The Eskay Creek deposit, located in northern British Columbia, is a high-grade gold/silver ore associated with complex polymetallic sulfides. Process development began in 1989 and continued through 1993. Because of the refractory nature of the ore, options including roasting and smelting were investigated. The selected process of pressure oxidation was the basis for basic engineering design until a re-evaluation of economics and risk indicated a preference for toll smelting. Although well proven in many industrial applications, pressure oxidation of the Eskay Creek ore dictated several innovations to solve problems associated with silver jarosite formation, preg-robbing, and high soluble copper and zinc concentrations.