Horizon Minerals Limited has completed a strategic review of the Nimbus silver-zinc project, located 15 kilometres east of Kalgoorlie-Boulder, Western Australia, inclusive of a detailed assessment of all previous Feasibility Study work completed to 2017.
Several expressions of interest were received to acquire or earn-in to the project, however, the Horizon board has now elected to retain the project on a 100 per cent basis with a view to update and complete the Definitive Feasibility Study (DFS) with a fully funded dedicated independent technical team.
Up until 2017, a significant amount of geological, metallurgical and engineering work had been completed on the Nimbus project with the completion of the comprehensive DFS put on hold due to depressed commodity prices. This included a partial DFS completed by Sedgman in 2015 when the Nimbus Project was held by MacPhersons Resources Limited.
The focus of this study was on capital and operating costs only, including plant design and flow sheets. Several ore processing options were reviewed based on extensive laboratory test work. The original strategy included a process to leach the silver to produce silver bars.
Horizon’s strategic review considered an alternative strategy to produce a high precious metal (silver) and zinc concentrate instead of silver bars.
According to the company, the production of a concentrate has potential benefits of a simplified processing circuit resulting in reduced capex and opex and to that end Horizon will undertake an offtake process to obtain expressions of interest, indicative terms and potentially an offtake agreement for the sale of silver-zinc concentrate.
Preliminary soundings have reportedly shown interest from some traders, particularly due to the high silver content. On the basis of achieving commercially viable terms, the company will then move to complete the DFS.
Nimbus is located adjacent to the Boorara Gold Project which creates potential synergies in a complementary development scenario. CSA Global has completed various due diligence, geological and mining studies between 2011 and 2015, and concluded in their August 2011 report that “…there is potential for future development of both oxide silver and primary sulphide zinc-silver projects, from the known mineralised zones around and below the existing pits and their extensions, and from discovery of new zones.”
Horizon’s Managing Director, Jon Price, said while the company’s focus remains firmly on gold, the strategic review has confirmed the potential for significant long-term shareholder value creation by retaining the asset at a time of sustained improvements in silver and zinc prices.
“The independent DFS team will now focus on the technical aspects and economic evaluation of mining the high-grade lodes and producing a high precious metal (silver) and zinc concentrate at site for sale to potential offtake partners,” Mr Price commented.
The Nimbus project has a prescribed premise licence in place to treat 120,000 ore tonnes per annum and an existing works approval to expand to 480,000 tonnes per annum. The company recently completed an application for renewal to extend the current licence.
Horizon has also commenced an independent technical and economic study of all previous work undertaken to evaluate options for the next steps in advancing the project. As part of the study, the high-grade lodes will be evaluated for potential early-stage development and concentrate production [1]. The study is expected to be completed in the December quarter of 2021.
Image of Horizon’s project area location (including the Nimbus silver-zinc project), courtesy of Horizon Minerals Limited.
Highlights from the Nimbus silver-zinc project:
- High grade silver resource of 260 kilotonnes at 774 grams per tonne (g/t) of silver (Ag) and 12.8 per cent zinc (Zn) contained in JORC 2012 Resources of 12.1 million tonnes at 52 g/t Ag, 0.9 per cent Zn and 0.2g/t Au [2].
- Deposit remains open at depth and along strike with significant potential to increase existing silver-zinc resources with further drilling [1].
- Significant regional exploration potential to find additional silver and other base metal deposits [1].
- Close proximity to Kalgoorlie-Boulder and existing infrastructure.
- Historical production of 3.6 million ounces of high-grade silver (352 g/t).
[1] See Forward-Looking and Cautionary Statements on Page 11 of the announcement here.
[2] As announced to the ASX by subsidiary MRP on 26 February, 30 April 2015 and 10 May 2016, see also Tables, Competent Persons Statement and Confirmation on Pages 5 and 10 of the announcement here.
