Koongie Park Project Potential – Proposed AKN Activities
There are three (3) primary areas that summarise the potential for AKN to develop the mineral resources at Koongie Park, namely:
- Optimising existing feasibility studies on the proposed mining of the Sandiego deposit incorporating results from planned resource extension drilling targeting extensions along strike and at depth;
- Carrying out a detailed exploration program across the Koongie Park Project tenures to identify additional base metals deposits to complement the existing Sandiego and Onedin resources. This includes possible drilling at depth below both deposits to identify sulphide extensions to mineralisation below the existing known oxide and transitional ore zones; and
- Trialling and evaluating the Ammleach® metallurgical process for the Onedin deposit which has shown good recovery test work results on other deposits with similar ore characteristics at Koongie Park.
Each of these is addressed in more detail as follows:
Optimise Sandiego mine feasibility studies
AAR completed a Pre-Feasibility Study (PFS) to assess the viability of a mining operation at the Sandiego deposit during October 2008. The PFS focussed on underground mining of the sulphide and transition ore zones at Sandiego, with construction of a 500tpa processing plant (using flotation techniques) with a 4-5 year operating life. CSA Global has identified in their Independent Technical Report that at the Sandiego deposit the primary copper and zinc mineralisation plunges at depth and to the south – leaving potential for the mineralisation to continue.
Schematic cross-section view of the Sandiego deposit.
An immediate activity of AKN upon completion of the KP Transaction will be to carry out a detailed optimisation review of the Sandiego PFS and all related mining studies. A key element of the optimisation work will be the design and conduct of a drilling program aimed at significantly expanding the existing known resources at Sandiego.
Regional Koongie Park Exploration
The region in and around the existing Koongie Park Project area is well-known for mineral occurrences as highlighted in the diagram below. CSA Global considers that the area is underexplored at depth and highly prospective for the discovery of further VMS base metal mineralisation below approximately 150m.
Geological map of Koongie Park showing tectonic units and mineral occurences
CSA Global has identified several factors about the Koongie Park Project that make it attractive for VMS exploration, namely:
- Favourable regional geological setting;
- Presence of proximal felsic volcanic facies and biomodal volcanism;
- Abundant mineralisation identified at numerous locations throughout a specific stratigraphic sequence;
- The presence of at least two sizeable existing VMS deposits; and
- The extent and intensity of the alteration indicative of a high heat flow system with high fluid to rock ratios.
A key feature of AKN’s initial exploration activities across the Koongie Park Project area will be the use of geophysical methods to drive future exploration drilling and assessment. Previous studies have concluded that the 50kms of strike of the project was incompletely explored by appropriate geophysical methods and that it was not unreasonable to expect that further VMS deposits could be discovered along the interpreted strike extent using geophysical methods. In the case of Koongie Park in particular:
- Koongie mineralisation is highly conductive;
- Koongie and other mineralisation are lenses;
- Country rock is highly resistive;
- Depth of weathering on sulphides is greater than elsewhere; and
- Mineralisation tends to follow a main trend,
all indicating that geophysical methods should be ideal for the initial Koonge Park Project exploration activities. Furthermore, the Geological Survey of Western Australia (GWSA) undertook in 2016 a comprehensive multi-commodity prospectivity analysis of the Halls Creek Orogen. This multi-author study used a GIS (geographic information system) driven, minerals system approach and developed a comprehensive set of prospectivity maps and images. The Pb-Zn-Cu-Ag prospectivity map generated by the GWSA highlighted that the Koongie Park Project area as the most prospective for these metals in the region.
Processing at Onedin
A focus of AKN’s early efforts to demonstrate a commercially viable metallurgical processing solution at Koongie Park’s Onedin deposit is access to the Ammleach® processing system. Ammleach® is a worldwide patented 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’s Onedin deposit) 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.