The Ammleach® minerals processing system
A focus of AKN’s efforts to demonstrate a commercially viable processing solution at Koongie Park’s Onedin deposit is access to the Ammleach® processing system. Ammleach® is a proprietary system that uses an ammonia-based process for leaching oxide and transitional ores that can then be subjected to normal solvent extraction and electro-winning processing.
The most common form of oxide/transitional ore leaching is by the use of sulphuric acid. However, with more complex oxide ores (such as at Koongie Park) one of the primary issues associated with leaching oxide ores can be the excessive use of sulphuric acid by a significant amount of carbonate minerals present in the ore. Not only does this use come at significant additional expense (making the process non-viable) but still may not achieve the levels of mineral recovery that is critical to establish an economically viable operation.
The Ammleach® process can leach complex ores that are otherwise uneconomic to treat (using traditional acid-based leaching technology) and operates at ambient temperature, making it an ideal process for either heap or tank leaching activities. Another advantage of the Ammleach® process is that the use of alkaline-based ammonia leaching (as opposed to the traditional acid leaching) can substantially reduce environmental impacts of the proposed operations.
AKN proposes to engage Perth-based Accudo Metals Pty Ltd (the holder of licence rights in Australia to the Ammleach® process) under a technical services agreement, whereby AKN will have access to Accudo’s metallurgical expertise and knowledge, including the Ammleach® process.