20~(th) ANNIVERSARY OF THE ANACONDA, BULONG, CAWSE NICKEL-COBALT HPAL PROJECTS DESIGN AND COMMISSIONING EXPERIENCES LESSONS LEARNED

摘要

The decade of the 1990's was perhaps the most significant time for Nickel, and its companion metal Cobalt, since the wartime era. The decade began with the break-up of the Soviet Union in 1991 followed closely by the discovery of the Voisey's Bay Ni-Co-Cu deposit in Canada, the last major nickel sulphide deposit found in the world. In 1995, WMC committed to a Simon-Carves Monsanto? sulphuric acid plant to be constructed at their Kalgoorlie Nickel Smelter. This enabler allowed the smaller of the so-called ABC Projects (Anaconda, Bulong, Cawse) to become feasible given a source of sulphuric acid. Anaconda, backed by exclusive use of Sherritt technology, chose to construct their own Monsanto? acid plant. These were the first plants to use HPAL technology since Freeport Sulphur Company built their Moa Bay operation in the late 1950's and the first to employ horizontal mechanically agitated autoclaves for the process. The paper will discuss the design of each HPAL circuit, specifically what was similar and what was different. It will segue into the commissioning stage which occurred 20 years ago and discuss what worked, what didn't and what should never be tried again. The mature technology that exists today was based upon the hard lessons learned during 1999. The future of Ni-Co is with laterites that exist in abundance, as sulphide hard rock mines become deeper and more costly to operate. This paper offers the unique perspective of the author who was employed by all three of the EPC/M companies that undertook groundbreaking design and implementation of these three projects as well as a role as Commissioning Engineer at Anaconda Nickel NL's Murrin Murrin Operations.