CESL’s facilities have a substantial amount of hydrometallurgical equipment and experience for the testing of various processes and flowsheets. Furthermore, CESL has its own analytical laboratory to support testing programs, an on-site maintenance and instrumentation team, and a world-class safety program. The variety and scale of installed equipment and the extensive experience allows CESL to manage various hydrometallurgical test programs that may be outside of the CESL Process conditions and operating parameters. This flexibility allows CESL to work on internal or client projects by technically evaluating new business opportunities, improving existing operations and developing new technologies. CESL’s staff and facilities are available to meet any hydrometallurgical project’s testing needs.
Metallurgical Testing
Overview ofMetallurgical Testing at CESL
The facilities at CESL offer three scales of testwork: bench, pilot or demonstration. CESL mitigates the technical risk of hydrometallurgical projects by applying a staged approach to process development supported by industry standard geochemical, mineralogical and metallurgical analytical capabilities.
In the development of technologies, CESL has worked with industry clients using various business arrangements. In general, a project is defined through bench testwork, followed by more detailed and integrated testing, including pilot campaigns once optimum process conditions are identified. Pilot testwork generally runs continuously on a range of concentrates or ores to demonstrate the flexibility of the operating conditions over a period of time to prove the process robustness and produce sufficient finished product and residue for market and environmental stability testing respectively.
Pilot and demonstration operations provide extensive metallurgical data (flowsheet and mass balance) to ensure optimal operations are achieved and sufficient data is collected in support of future engineering studies. Flowsheet design and operations are managed by a technical team which includes engineers, scientists, and technicians with significant experience in hydrometallurgical processing including pressure leaching, solid-liquid separation, solvent extraction and electrowinning.
CESL Testwork
Pressure leaching testwork can be performed using batch bench scale autoclaves. The CESL facility has the ability to conduct tests using 2 and 20 litre autoclaves.
The purpose of bench scale testwork is to develop the basic metallurgy of the concentrate sample. In many cases this work is now supported by quantitative mineralogy carried out using advanced analytical equipment at Teck’s Applied Research &Technology Centre located in Trail, B.C., Canada. Over 100 sulphide concentrates have been tested by bench scale pressure oxidation for copper, copper/gold, zinc and nickel-cobalt projects. In total, more than 5,000 batch autoclave leaches have been performed at the CESL facility. Normally, a concentrate sample of 5-10 kg is sufficient to complete an initial set of bench autoclave tests.
Continuous pilot plant campaigns, from concentrate re-grind through to production of LME grade-A copper cathode (35 kg/day), are conducted at CESL. The pilot plant facilities are also capable of recovering nickel, cobalt and zinc from sulphide concentrates. A fully integrated precious metal recovery circuit is on site to recover gold and silver from the leach residue. Various flowsheet configurations are possible within the pilot plant facilities using standard unit operations. Key equipment and installed unit operations include:
- 30 litre titanium and stainless autoclaves
- Thickening and filtration equipment
- Atmospheric leach vessels
- Solvent extraction and electrowinning
- Neutralization and purification circuits
- Cyanide regeneration and destruction
- Gold and silver recovery (carbon)
The fully integrated pilot plant is used to prove the process flowsheet. Since 1992, 25 Pilot Plant campaigns for copper, copper/gold, zinc and nickel-cobalt projects have been undertaken at the CESL facility with over 20,000 hours of continuous Pilot Plant operation. Typically, a concentrate sample of 6 to 8 tonnes is sufficient to complete an integrated 60-day Pilot Plant campaign.
The CESL Demonstration Plant consists of a fully integrated copper plant, from concentrate re-grind through to production of commercial size LME grade A copper cathode as well as residue treatment for the recovery of gold and silver. The Demonstration Plant utilizes small-scale commercial equipment which allows for the collection of engineering data for accurate scale-up of process equipment. Key equipment and installed unit operations includes:
- 800 and 1,000 litre titanium autoclave vessels
- 500 litre stainless autoclave vessel
- Thickening and filtration equipment
- Atmospheric leach vessels
- Solvent extraction and electrowinning
- Evaporation and crystallization equipment
- Neutralization and purification circuits
- Cyanide regeneration and destruction
- Gold and silver recovery (carbon, electrowinning)
Since 1997, seven Demonstration Plant campaigns for copper projects have been undertaken at the CESL facility with over 5,000 hours of continuous plant operation and treatment of over 1,000 tonnes of copper concentrate. A sample of over one hundred tonnes of concentrate is required to complete a demonstration plant campaign.
The variety and scale of installed equipment allows CESL to manage various hydrometallurgical test programs that may be outside of the CESL Process conditions and operating parameters. This flexibility allows CESL to work on internal or client projects in a variety of ways including:
- Incrementally improving existing operations
- Developing breakthrough technologies
- Assessing new and competing technologies
- Technically evaluating new business opportunities
- Managing R&D projects
