Tecnicas Reunidas developments: Technology based strategies for zinc smelters

Jaime Calvo, Ana Belen Mejías, Emilio Pecharroman, Carlos Álvarez Carreño

Environment conditions for zinc refineries are growingly difficult due to different circumstances, being global over-capacity and slower demand growth, increasingly complex raw materials and sustainability requirements the most relevant. These are having a direct impact on the business model of traditional zinc refineries causing many to become un-feasible. Tecnicas Reunidas is a technology developer and licensor in the field of base metals with more than 45 years of experience. TR has a wide experience with alternative raw materials and development of environment-friendly technologies. This paper shows the last technical developments, some already commercialized, some still at development stage, performed by TR to reply to different zinc refinery’s needs. These developments are linked to ZINCEXTM Solvent Extraction technology implemented in 7 industrial plants since 1976 and which, to date, has enabled the production of zinc from complex raw materials (oxidic ores and Waelz oxides) at very low cost. The technological developments have been performed looking for increasing refineries feasibility in at least one of the following three areas of improvement: Capacity utilization, Adding value and Cost efficiency. The developments described in this paper are: Design of an industrial zinc refinery based on Roasting-Leaching-Solvent Extraction-Electrowinning, especially suitable for zinc concentrates with high content of impurities like manganese and magnesium. Industrial implementation of ECOLEADTM technology for the recovery of lead and silver from a zinc refinery fed exclusively with secondary raw materials (Waelz oxides) Significant investment cost reduction at same operating cost with the new generation of the ZINCEXTM Technology. Recovery of rare earths and critical metals from ZINCEXTM refinery streams. Adaptation of the ZINCEXTM Technology to small sized plants, especially suitable for metals recycling facilities and recovery from waste streams.