Ni Laterite Experience
10 years involvement in modelling and development of complex hydrometallurgical Nickel Laterite processing plants.
USD 6 Billion of processing plant built on our modelling modelling results.
Design
Other Hydromet
Mineral Processing
Pyromet
Power
Other Utilities
Control System Functional ___Descriptions
Our inolvement in specific projects has been:
Cawse ___________Study to end commissioning, process engineer for CCD, Neutralisation, MHP Precip, Ammonia Leach
Ravensthorpe______Start of project to completion of heat and mass balance. Produced complete H&MB
Goro_____________Start of Phase 2B to present (ongoing). Produced complete H&MB.
Rio Tuba__________Review of METSIM model.
Murrin Murrin_______Expert witness on Process Modelling. Various periods of on-site consulting and trouble shooting.
The first high Pressure Acid Leach (PAL) processing plant for Ni Laterites was built in Cuba in the 1960's.
The second wave of pressure acid leach plants were built in Western Australia in the late 90's. The Cawse, Bulong, and Murrin Murrin plants were being designed and built almost simultaneously, with Cawse being slightly ahead on timing, and a long way ahead in terms of the performance of the process and plant.
As money making machines, these plants were not good. For various reasons each failed the primary objective of achieving the required return on investment by making Ni in a safe and sustainable manner.
But the PAL technology was advanced, and explanations (some better than others) are offered for many of the technical problems, and so with huge reserves of lateritic Ni available and growing demand for Ni the combination of PAL with some form of solution purification and metal refining continues to offer an attractive route for bringing more Ni to the market in a profitable and sustainable manner.
Circuits modelled at various stages of design or for studies include:
Feed prep with upgrade, PAL circuits w direct and indirect heating and various process conditions, Neutralisation, CCD, MHP, MSP, NH3 Leach, NH3 recovery, RIP, Mn Removal, NH3 SX, Cl SX, Direct SX, EW, Hydrogen Reduction, Pyrohydrolysis,Atm Leach.
Some of the models we have done are large:
Having a fully integrated model with utilities and services and complete closing of the water balance is very important as these complex hydrometallurgical plants rely on the integration of systems for the economy of energy use and water recycle.
We have no problems building very large models (2,000 unit operations, 200 species or components, 3,000 streams) because we model in a systematic way. Complexity does not necessarily increase with the number of units. Complexity increases exponentially when inconsistent methods are used (generally from lack of experience) and when the modelling is being forced to generate non-mechanisitic results.
Although we can and do use various process modelling software systems, there are few that have been proven with such large models, to be able to handle the full range of unit operations encountered, and which provide the flexibility and the disciplined structure to build solid stable models that give sensible results.