Investigator Resources continues to make strong progress at its Paris silver project in South Australia with a key definitive feasibility study (DFS) underway.
The company has recently successfully progressed and completed a number of key studies as it continues to advance the proposed Paris development.
Investigator has been implementing data from a baseline environmental audit which was undertaken across the Peterlumbo tenement early in the exploration phase at Paris.
To add to that work, specialist firm JBS&G has recently been appointed as environmental consultants following a successful competitive tender.
A work plan was developed for an additional field survey and a team was mobilised to site and completed a field survey, building on prior survey work and addressing gaps in knowledge identified from both a flora and fauna perspective.
The focus of the flora program was the collection of vegetation data relevant to federal and state Acts such as the Native Vegetation Act 1991 and Native Vegetation Regulations 2017.
Engineering contract awarded
Elsewhere, Melbourne-based engineering, procurement and construction consultancy group Mincore has been appointed to deliver key aspects of the Paris pre-feasibility study (PFS).
Having undertaken the engineering design and cost estimation for the Paris PFS in 2021, Mincore’s familiarity with the Paris project will help it build on prior knowledge and have a reputation of delivering fit-for-purpose outcomes.
A key focus of the DFS is to advance the detail and validate the assumptions made in the PFS.
Mincore has commenced work on a review of project aspects including process plant design and layout drawings (including equipment arrangement), infrastructure requirements, and the delivery of utilities such as power and water.
It will also develop capital cost estimates for the purchase, construction and commissioning of the facilities.
Minerals processing consultant MinAssist will continue to provide key support and act on behalf of Investigator as the owner’s representative for all engineering tasks.
Hydrological modelling planning
Meanwhile, progress is being made on hydrological modelling of the data acquired during drilling and pump testing completed in July 2023.
The modelling of groundwater within the Paris deposit has neared completion and includes the development of regional gradients, geological domaining and dewatering aspects of the proposed Paris open pit.
Modelling of the Hector bore field, the planned source of process plant water supply, is being finalised.
During this phase of work, Investigator consulted with representatives of the South Australian Department for Energy and Mining and the Department for Environment and Water to ensure that basic modelling parameters and assumptions were in line with departmental expectations.
Hydrological data proximal to the pit environment and a dewatering model have been provided to Investigator’s geotechnical consultant to allow completion of geotechnical assessments and input prior to open pit optimisation using the updated 2023 mineral resource estimate.
Metallurgical test work on lead potential
Further work is planned to investigate the potential to add value to the project with the processing of lead.
Whilst a minor component of the Paris deposit, the company believes that lead has the potential to add value to the project and was not considered in the 2021 pre-feasibility study.
A program of lead recovery test work was developed, and a comprehensive analysis of drill hole assay data was used to identify that a sufficient volume of samples to support this test work could be compiled from both retained assay pulps and drill holes samples.
Metallurgical test work continues to progress with focus on lead flotation from samples of both sulphide and oxidised mineralisation.
Updated mineral resource estimate
The value of the Paris project continues to grow with the company releasing an updated mineral resource estimate early in the September quarter.
The new JORC 2012 mineral resource estimate of 24 million tonnes at 73 grams per tonne silver and 0.41% lead for 57 million ounces of silver and 99,000 tonnes of lead represented a 7% increase on the previous 2021 mineral resource estimate.
An additional 76 holes, drilled since the 2021 resource update, were included in that mineral resource estimate.
Whilst the majority of those holes targeted the potential resource extension to the south of Paris, additional exploration drilling was completed along the western and eastern flanks of the deposit as well as in the central zone of the resource – located between the optimised northern and southern pits.
Closer spaced infill drilling in the central zone and further drilling to the north-east of the deposit has provided a more detailed and deliverable result, with a consequential reduction of resource ounces in these areas.
