Studies

Advancing Project, Economic, and Environmental Studies

Overview
Pre-Feasibility Study
Scoping Study
Ore Sorting Test Work

Development Scenario Based on a Low Cost, Low Strip Ratio, Open Pit with Truck and Shovel Mining Operations, with Conventional Centralized Processing Plants

Key Studies Underway

Image - Environmental Studies - Ongoing environmental baseline studies include surface and ground water sampling and modelling, wetlands mapping, and wildlife surveys.
Image - Stakeholder Engagement - Continuing positive engagement with stakeholders, regulators, and our local communities.
Image - Host Rock Studies - Ongoing hydrogeological , geotechnical, and waste rock geochemical characterization studies.
Image - Metallurgical Studies - Ongoing metallurgical studies including heap leach, ore sorting, CIL, and critical minerals by-product extraction.

Current and proposed conceptual flowsheet, which is being tested as part of the PFS level studies underway

Scoping Study Confirms the Potential for a Commercially Robust Mining Operation at the Estelle Gold Project

Snap shot in time May 2023

The Study represents a snapshot in time utilizing the resources from 3 of the 4 currently defined large deposits within the Estelle Gold Project (RPM North, RPM South and Korbel Main), based a mining scenario which focused on the higher grade material. The Study highlights the technical and financial robustness for Estelle to support a large open pit mining operation, with ideal ore body geometry that allows mining high-grade ore in the early years for a quick payback from RPM, and bulk tonnage mining from Korbel at a low strip ratio in the later years, using a central processing plant located at Korbel.

Test work has indicated that the gold is easily liberated with an average recovery of 88.3% using conventional processing methods and Nova intends to undertake fines by-pass test work which has the potential to further increase the LOM production schedule and most importantly also reduce waste.

Sensitivity analysis shows the project is highly sensitive to mill feed grade

The sensitivity analysis showed that the Project’s overall economics is highly sensitive to mill feed grade, with just a 10% increase in the LOM mill feed grade from the current 0.73 g/t Au to 0.8 g/t Au potentially increasing the Project’s NPV by USD$277M to USD$931M. As a result Nova’s core focus now is to define minable resources to increase the LOM mill feed grade above the 0.73 g/t Au, and we know where to look, RPM, Train and Cathedral

The Scoping Study is based on a solid foundation with reputable engineering firms, detailed and conservative geological modelling, extensive test work and front-ended high grade ore. It provides great exploration upside and a solid platform for growth and has identified clear opportunities for immediate improvement of metallurgical test works that would add to the bottom line.

Particle Density XRT Ore Sorting Works Extremely Well on the Estelle Ore Bodies

Particle density XRT (X-Ray Transmission density ore sorting, NOT optical ore sorting) ore sorting is a proven technology which has been successfully implemented as part of the pre-treatment concentration process in many mines around the world (see below for examples of mines using or intending to use ore sorting). X-rays are used to examine the density of the rock being sorted in order to separate a target mineral, ore or element from waste prior to the haulage, crushing and processing mining stages. By rejecting a considerable proportion of the lower grade rock before processing through the mill, the mill feed grade is effectively increased and energy requirements and tailings generation are reduced, resulting in a more environmentally friendly mining operation with improved overall mine efficiencies and economic benefits.

The process starts with raw ore being scanned with X-rays and data collected from the detector. With the help of big data and intelligent algorithms, the ore and waste rock is separately identified and a high-pressure blower sprays the waste rock away to realize efficient automatic intelligent sorting.

Ore sorting test work completed on Estelle drill core at Tomra’s assessment site in Sydney has shown that particle XRT ore sorting technology works extremely well on the Estelle ore bodies as the gold is contained in sheeted veins within the high density (4-7 S.G) arsenopyrite rock which is vastly different to the lower density (2 S.G) country rock. Extensive testing has shown the potential to upgrade 0.4 g/t Au material up to 6 g/t Au, with the optimum at 0.73 g/t Au. This allows Nova to operate at a lower cut-off grade with reduced processing costs and increased mine production.

The recent strategic review also recommended reviewing various selective ore sorting options on material from both RPM and Korbel with a combination of different sensors and conducting a pilot scale ore sorting test program.

Nova envisages the density based XRT ore sorters to come online in the later years, well after the payback period and through cash flow. The sorters can be installed on a modeller basis without a high capital intensity as all infrastructure will already be established.

Mining Companies Currently Using or Proposing to Use Ore Sorters

  • Degrey Mining – Malina Gold Project, Toweranna Deposit (Gold), Western Australia, Australia – Information link here
  • Pilbara Minerals – Pilgangoora Project (Lithium), Western Australia, Australia – Information link here
  • Vista Gold Corp – Mt Todd Gold Project (Gold), Northern Territory, Australia – Infomation link here
  • Couer Mining – Kensington Gold Mine (Gold), Southeast Alaska, USA – Information link here
  • Stornoway Diamond Corp – Renard Mine (Diamonds), Quebec, Canada – Information link here
  • Mikroman Mining – Mugla, Aydin & Usak mines (Quartz), Turkey – Information link here
  • Gowest Gold – Bradshaw Deposit (Gold), Ontario, Canada – Information link here
  • Agino Eagle – Sinter Deposit & Pinos Altos Mine (Gold), Chihuahua State, Mexico – Information link here
  • Pantoro Ltd – Nicholsons Project (Gold), Western Australia, Australia – Information link here
  • Minsur – San Rafael Mine (Tin), Peru – Information link here