The AMIRA Gold Processing Technology project is a collaborative industry funded project which has operated since 1984. Over the last 33 years the project has covered a wide range of topics within the general areas of gold ore processing and environmental management of tailings. The project is based at the Western Australian School of Mines, Curtin University (Perth, Western Australia).
This website is the access portal for project information and resources, and is available to all employees of companies sponsoring the current project cycle, P420F (2016-2019). See below for the list of current industry sponsors.
The current three year program (P420F) commenced in June 2016 and is divided into five themes:
Theme 1: Enabling process optimisation
Theme 1 is the vehicle for technology transfer of best principles and practices in gold processing. This theme delivers immediate value, often greater than the sponsorship fee. It aims to entrench the knowledge and skills in operational staff derived during earlier AMIRA P420 iterations, whilst empowering them to utilise a suite of powerful, user-friendly process models. This theme includes consulting visits and circuit assessments, backed up with workshops and professional development of staff.
Theme 2: Optimising post-crush liberation
Theme 2 is focussed on reducing the processing costs associated with low grade ores, either through optimal pre-concentration (coarse particle gangue rejection), or through optimised heap leaching. Grinding barren gangue not only leads to an excessive waste of energy in grinding, as well as high reagent costs, high dewatering costs, high water losses and high disposal and treatment costs. Coarse particle gangue rejection seems therefore to be an obvious approach, particularly if applied as early as possible to the stope face. Yet this research area remains poorly explored, quantified and modelled. Theme 2 therefore evaluates crushing from two perspectives: (a) optimal liberation of barren gangue in the 0.3 - 5.0 mm (pumpable) particle size, and (b) optimal introduction of micro-fractures for the leaching of gold ores (including polymetallic gold ores). These optimisation objectives require novel approaches to quantification of practical mineral liberation and exposure, and subsequent separation and removal of barren gangue prior to ball-mill based grinding. The optimisation of barren gangue liberation for various crushing modes, and the subsequent gangue removal, as well as the modelling of integrated crushing-screening-(gravity) separation circuits are to be the research thrusts of this theme.
Theme 3: Optimising reagents & consumables
Theme 3 explores the potential of new or optimised conventional reagents and consumables to lower overall processing costs or yield higher recoveries, whilst reducing the overall environmental and occupational health and safety risks. There have been exciting developments in the potential of new horizon reagents and consumables, as well as in the optimisation of existing reagent suites, that can aid in unlocking the cost challenges associated with polymetallic and refractory ores, and even in the optimisation of existing operations.
Theme 4: Managing the water balance and water chemistry
Theme 4 seeks to address one of the most pressing problems facing processing operations: the decreasing availability of water of suitable quality amidst ever increasing climatic and societal pressures. A two-pronged approach is taken: (a) to improve the management of the plant’s water balance through selective ion-control to allow for early rejection of reagent consumers and scale formers, whilst allowing for improved water and reagent recovery; and (b) to explore a technological strategy for dry processing (as far down the processing value chain as possible).
Theme 5: Enhancing the processing of difficult ores
Theme 5 deals with difficult ores, be they polymetallic, refractory and/or preg-robbing. As most of the free-milling gold ore deposits are being depleted, the industry has to increasingly direct its efforts to processing these difficult hydrothermal ores. However, conventional approaches and reagent suites tend to be uneconomical and operationally very challenging. This theme takes an integrated techno-economic approach to introduce novel technologies, developed within and without the GTG to address the processing of these ores. It includes the techno-economic evaluation of the novel technologies on the ores of the sponsors (one per Operating Sponsor) within the context of the overall flow sheet. In particular, glycine (a non-toxic, low cost, mass produced reagent) used in an alkaline environment is evaluated for the leaching, metal and reagent recovery, recycling and reuse. The reagent suite has patents pending and was developed by Curtin University for the leaching of gold, silver, all copper minerals, nickel, cobalt, zinc, lead and platinum group metals. In addition, Theme 5 will focus on the treatment of high silver gold ores with a significant preg-robbing component, and the treatment of refractory ores with novel oxidative processing approaches.
For more information on the project, please contact Professor Jacques Eksteen.
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