Case Studies

Lihir Pressure Oxidation Expansion
Project
Lihir Pressure Oxidation Expansion
Client
Lihir Gold Limited
Location
Lihir Island, Papua New Guinea
Scope
Feasibility Engineering and Autoclave Design
Completion Date
Autoclave Design Completed 2008, commissioning planned for 2011

Sherritt Technologies developed cost estimates for a bankable feasibility study for Lihir Gold Limited’s pressure oxidation circuit expansion and the design of the new pressure oxidation autoclave for its plant in Papua New Guinea. Upon completion in 2011, the Lihir autoclave became the largest autoclave in metallurgical operation in the world.

Sherritt Technologies provided the technology for Lihir’s original pressure oxidation plant which consisted of three autoclaves operating in parallel which were commissioned in 1997. Sherritt Technologies has enjoyed a close relationship with Lihir over the years and when Lihir seriously contemplated an expansion in 2006, Sherritt Technologies was contracted for confirmatory laboratory test work and the design of the new pressure oxidation circuit and autoclave.

Lihir awarded the contract for the new autoclave based on Sherritt Technologies’ design. The carbon steel shell refractory lined vessel was the largest autoclave operating in the world when the circuit was commissioned on 2011.

Specific activities carried out for the Lihir Gold expansion project were:

  • Confirmatory laboratory test work to develop process design criteria.
  • Development of process design package for the pressure oxidation expansion area.
  • Working with subcontractors, Sherritt developed the pressure oxidation area design and provided cost estimates used by Lihir for project approval.
  • Developed the detailed autoclave design for Lihir to solicit bids and select the autoclave fabricator and refractory supplier.
Hudson Bay Mining and Smelting Zinc Pressure Leach
Project
Hudson Bay Mining and Smelting Zinc Pressure Leach
Client
Hudson Bay Mining and Smelting (Now Hudbay Minerals)
Location
Flin Flon, Manitoba, Canada
Scope
Process Test work and Process Design, Process Licensor, Autoclave Design, Training, Commissioning and Ongoing Technical Support
Completion Date
1993

The Hudson Bay zinc pressure leach project was the first application of Sherritt’s two stage zinc pressure leach process. The Hudson’s Bay plant followed the successful application of single stage zinc pressure leaching technology at Teck Cominco in Trail, at Xstrata in Timmins and for Ruhr Zink at Datteln Germany.

The commercialization at Flin Flon culminated many years of process development work with Hudson’s Bay Mining and Smelting. Sherritt Technologies worked closely with the engineering contractor, Fluor Daniel, to successfully implement the technology. The zinc pressure leach plant reached full production within four months of first feed to an autoclave.

Specific activities carried out for the HBMS zinc pressure leach project included:

  • Batch, continuous and integrated laboratory test work.
  • Development of process design criteria for the zinc pressure leach area.
  • Working closely with the engineering contractor throughout the design process to ensure the technology was implemented successfully.
  • Prepared operator manuals and presented operator and maintenance training.
  • Commissioned the pressure leach plant and provided ongoing technical support.
Moa Nickel – A Sherritt-Cuba Success Story
Project
Moa Joint Venture
Client
Sherritt
Location
Moa, Cuba
Scope

Completion Date

The laterite processing plant located at Moa, Cuba was originally designed based on a unique high pressure acid leaching process developed by the Chemical Construction Company. A division of the Freeport Sulphur Company built the facility in Moa and the plant was commissioned in 1959. Shortly thereafter the Cuban government imposed a much higher tax and royalty structure on the nickel business and Freeport made the decision to shut down the operation since it was not profitable under the new constraints. The plant was restarted in 1961 by the Cubans, but struggled to reach design operating rates, even with technical assistance and equipment supply from the former Soviet Union.

Of interest is that technology developed by the Chemical Construction Company was ultimately assigned to Sherritt Gordon Mines Ltd and Sherritt subsequently licensed this technology to other commercial operations.

When the former Soviet Union unraveled following the events of 1989, Moa Nickel found itself without an outlet for its mixed sulphides product. Sherritt also found itself short of feed materials for its Fort Saskatchewan refinery. An approach to the Cuban Nickel Industry to purchase mixed sulphides was accepted, and the first shipment of Moa Nickel mixed sulphides was fed to the refinery in May of 1991. That initial contact led to Sherritt subsequently purchasing essentially all of the Moa Nickel production. Because of the high cobalt content of this material, a radical redesign of the leaching and nickel cobalt separation process was required. The new process was piloted, designed and constructed on a “fast track basis” and the process was commissioned in May 1992. The cobalt plant capacity also was increased to handle the much higher cobalt content of the Moa material by the end of 1992. Sherritt’s technical, research and operations expertise was critical to the successful process development, design, construction and commissioning of the new facilities.

The mixed sulphides production from Moa was slowly declining at this time, and Sherritt’s nickel production was correspondingly dropping, so Sherritt’s executive approached the Cuban government to form a joint venture consolidating the operations in Cuba with the nickel refinery at Fort Saskatchewan. The JV, a 50-50 partnership between Sherritt and General Nickel Co of Cuba became a reality in December 1994. With Sherritt’s technical and management assistance, as well as access to capital to rehabilitate the Cuban operations, nickel output increased from about 50% of design at the time the JV was formed to above design production within two years. The plant has since been expanded to about 38,000 t/y of nickel plus cobalt in mixed sulphides.

Ambatovy Laterite HPAL and Refinery Project
Project
Ambatovy Laterite HPAL and Refinery Project
Client
Ambatovy Joint Venture
Location
Toamasina, Madagascar
Scope
Batch process development testwork, continuous piloting, basic engineering, feasibility study management, detailed engineering assistance, commissioning , operations technical support and management
Chronology
Date Development and feasibility engineering conducted 2004 to 2007.Detailed engineering 2008-2010. Commissioning 2012, commercial production declared January 2014, Production Test completion, Q1 2015

Sherritt Technologies (Dynatec prior to 2008) carried out all of the batch process development test work and continuous pilot plant testing, for the Ambatovy laterite processing facilities in Madagascar. The work included preparation of conceptual and basic engineering design, detailed design for specific autoclave circuits and management and assistance with preparation of the Bankable Feasibility Study for the project. Dynatec Corporation was the developer of the Ambatovy project and was subsequently purchased by Sherritt International in 2007, which formed the Ambatovy Joint Venture with partners Sumitomo Corporation, Kores, and SNC Lavalin, to construct the Ambatovy mine, laterite processing facilities, a nickel refinery and associated infrastructure in Madagascar. Sherritt is 40% owner and the operator. The plant started up in March, 2012 and the first nickel metal was produced in June of that year. It is the largest integrated nickel laterite mine, processing plant and refinery in the world, with a capacity of 60,000 t/y of finished nickel production.

The Ambatovy plant site is located in Toamasina, on the east coast of Madagscar. Laterite ore slurry is delivered from the mine site via a 220km pipeline and is processed through 5 HPAL autoclave trains, amongst the largest in the world. Nickel and cobalt are precipitated from neutralized leach solution using hydrogen sulphide. The precipitated mixed sulphides are leached in the adjacent refinery and nickel and cobalt powders are recovered from refinery solutions via hydrogen reduction. A similar process is employed at Glencore’s Murrin Murrin facility in Western Australia, for which Sherritt also carried out the process development test work, basic engineering design and commissioning assistance.

Specific activities carried out for the Ambatovy project were:

  • Laboratory batch and continuous pilot plant test work to develop process design criteria for the commercial plant, including acid pressure leaching, CCD, solution neutralization, mixed sulphide precipitation, sulphides leaching, solution purification, solvent extraction and hydrogen reduction.
  • Pilot plant testing of the ore slurry preparation circuit at the mine site in Madagascar.
  • Basic engineering design for all of the laterite ore processing plant, excluding the solvent extraction area in the refinery.
  • Development of detailed design packages for specific autoclave areas including HPAL, sulphides leach and nickel/cobalt reduction areas.
  • Liaison with the selected EPCM contractor during the detailed design, procurement and construction phases of the project.
  • Assisted in executing the pre-commissioning activities.
  • Provided personnel for commissioning, operations, technical services and management to the Ambatovy JV.
  • Provided ongoing technical services and site personnel to assist with ramp-up and optimization of the processing plants.