Yandal Resources Ltd’s (ASX:YRL) is progressing well with feasibility study activities at the Flushing Meadows prospect within the Ironstone Well Gold Project in Western Australia.
A geotechnical diamond drilling program has been completed and the holes equipped for groundwater monitoring as part of open pit dewatering and flow testing studies next month.
Notably, new oxide gold mineralisation from four HQ triple tube diamond core holes has been intersected including;
- 2.9 metres at 4.46 g/t from 29 metres including 1-metre at 7.96 g/t;
- 9.6 metres at 3.7 g/t from 54 metres including 1-metre at 16.92 g/t; and
- 6.04 metres at 2.88 g/t from 32.96 metres including 1.04 metres at 12.78 g/t.
Assays from deeper down hole representing transitional and primary zones are pending with results expected in the December quarter.
Updated resource estimate pending
An upgraded mineral resource estimate is planned for completion in October 2020 with the intention to elevate a portion of inferred resources to the indicated category.
Digital modelling of geology and mineralisation envelopes has been completed ahead of independent data verification and compilation of an updated estimate and block model suitable for economic assessment.
A close-spaced RC drilling program will be designed to reduce assay data density in several key mineralised areas of the resource both above and below the standing groundwater table as part of ongoing quality assurance/quality control programs.
The aim of the programs will be to improve confidence in modelling parameters, grade estimation and grade continuity to assess economic risk once mine approvals are granted.
Flushing Meadows prospect collar plan showing the collar locations of completed RC holes with assays received and pending, and historic holes.
Toll mill potential
Flushing Meadows is in close proximity to a number of gold development projects and operating carbon-in-leach (CIL) processing plants.
In the December quarter 2019, the company released the results of early-stage metallurgical test-work from composited RC drill hole samples representing oxide material above 80 metres vertical depth at a grind size of 106 microns, which returned an average of 94.1% gold recovery from conventional gravity and cyanide leach processing.
A transitional RC drill sample from between 89-94 metres vertical depth ground to 75 microns returned 84% recovery with gold associated with around 4% pyrite and minor arsenopyrite.
The gravity and cyanide gold recoveries from mineralised oxide and transitional material at the grind sizes tested are acceptable for existing third party CIL processing plants in the region.
Metallurgical work underway
As core samples containing mineralised material are now available, a new more detailed metallurgical study is underway to determine additional gold recovery and processing parameters under potential toll milling scenarios.
In addition, parallel to the open pit and offsite processing feasibility study, a program to assess the potential for a standalone heap leach and recovery operation has started.
Bulk quantities of mineralised intervals from reverse circulation drill samples have been delivered to ALS for an initial work program.
Results from both programs are expected in the December quarter.
Mine design and permitting
Pit optimisation studies, mine design and ore reserve estimation are set to be completed by Intermine Engineering Consultants and will utilise information supplied by independent technical consultants, mining and haulage contractors and Yandal Resources.
An initial flora and fauna survey was completed by Botanica Consulting in 2019 and this company has been retained to complete mining proposal, mine closure plan and clearing permit applications.
The company is also in the early stages of engagement with Central Desert Native Title Services Limited (authorised by Kultju Aboriginal Corporation to act as its agent in regards to land access negotiations and agreements), the Shire of Wiluna and the Department of Mines, Industry, Regulation and Safety to work towards the completion of all statutory approvals to mine.
Key exploration and development activities planned during the September and December quarters include:
- Complete groundwater, geotechnical assessment, resource update, pit optimisation and design for Flushing Meadows;
- Receive and review pending 1-metre results from Gordons Dam RC and AC drilling;
- RC drill test Mt McClure and regional targets within the Barwidgee and Ironstone Well projects; and
- Complete maiden resource estimate and diamond drilling at Gordons Dam.