Bushranger second stage pre-concentration study

RNS Number : 7787S
Xtract Resources plc
18 June 2024

Xtract Resources Plc

(“Xtract” or the “Company”)

Second Stage Pre-Concentration study for the Bushranger Copper-Gold Project

The Board of Xtract Resources Plc (“Xtract” or the “Company”) is pleased to announce the results of a second stage review of pre-concentration options for the Bushranger project in the Lachlan fold NSW, Australia prepared for the Company by Altrius Consulting Pty (“Altrius”).


·    The Altrius review concluded that while the Racecourse mineralisation is not considered amenable to upgrade by Tomra ore sorting, other methods of ore sorting/pre-concentration may be more suitable and the Bushranger flowsheet may benefit from alternative pre-concentration technologies. To this end Altrius has recommended further test work on Pre-Screening, Gravity Separation and Coarse Particle Floatation.

·    Accordingly, test work is now being undertaken by ALS in Perth on Pre-Screening and Dense Media Separation (two separate tests).

·    In addition, the Company has commissioned NovaCell Coarse Particle Floatation test work, and this work is progressing favourably.

·    As previously reported, the Bushranger Racecourse project has the potential to be economically mined at rates of 20Mtpa or greater at USD10,000 per tonne copper price or above. The objective of the current work is to re-assess the breakeven copper price for the Project.

The Company will provide an update on the initial results which are expected before the end of the third quarter of this year.

Colin Bird Executive Chairman said:

“The forecast shortage of copper together with increasing demand has finally convinced the industry, that new copper resources have to be found on an urgent basis.  The Bushranger project, whilst marginal at previous prices, becomes as previously reported NPV positive at USD10,000 per tonne copper.  The project has the benefit of a high-grade component, which can be optimised and integrated into future mining plans.

Whilst the area that has been studied contains a previously reported resources of some 1.1 million tonnes of contained copper, the project is geologically open in most directions notwithstanding the relatively unexplored Ascot section.

It is our intention, if the current tests results are positive, to rework our financial and technical plans to re-assess the break-even copper price for the project.  We will keep the market appraised of progress as the information is received and integrated into our base model.”


The Board believes that the forecast copper supply shortage will bring into production a next stage generation of porphyries, which in recent years may have been considered technically or financially marginal.

Bushranger fits into this new next generation category and the Board have committed expenditure to carry out more detailed pre-concentration work to follow the initial assessment leading to the financial study reported in November 2023 (see RNS dated 6 November 2023).

Ore Pre-Concentration Test Work Programme on Mineralisation from the Racecourse Mineral Resource

Previously published preliminary studies conducted by Optimal Mining on the Bushranger Gold-Copper Project (“Optimal Studies”), completed in 2022 and 2023, concluded that a minimum mining rate of 20 Mtpa, and copper price more than US$10,000/tonne, are required to generate a positive Net Present Value (“NPV”) from the project (see RNS dated 7 March 2023). Project economics measured as NPV, can potentially be improved by means of ore pre-concentration which is aimed at:

·    Increasing feed grade (%Cu/t) to processing plant which in turn will lead to;

·    Reduction in tonnes processed for the same final product volumes and thus lower unit production costs.

Altrius was commissioned by Xtract to undertake a review of the metallurgical and pre-concentration test work previously completed (see RNS dated 20 July 2023) and conduct a desk top assessment of the available pre-concentration technologies. The outcomes of the assessment of the historical Optimal Studies test work included:

·    Copper occurring as chalcopyrite is finely disseminated and is associated with pyrite and pyrrhotite, both of which are considered easily floatable mineral types.

·    Sighter rougher flotation test work yielded very good Cu recoveries between 92% and 96% into a concentrate containing between 5% and 6% Cu with the rougher concentrates containing negligible penalty elements.

·    Cleaner flotation test work (excluding regrinding) achieved Cu concentrate grades between 12% and 27%, with Cu recovery of between 81% and 92%.  Gold recovery to concentrate ranged from 35% to 55% with an accompanying gold grade of 0.30 g/t to 5.4 g/t.

·    Re-grinding of the copper-gold concentrate to 15µm improved cleaner concentrate grade to between 19% and 27% Cu, at a final copper recovery of between 78% and 89%.

The Optimal Studies indicated that the Racecourse deposit’s copper-gold mineralisation is amenable to conventional flotation processes. Pre-concentration technologies may in turn significantly benefit processing of the Racecourse copper-gold mineralisation, with a subsequent potential improvement to the overall project NPV. 

The most prominent pre-concentration processes currently used throughout the mining industry on different ore types are:

–      Blasting (or selective mining)

–      Screening

–      Ore sorting (bulk or particle based)

–      Gravity separation

–      Magnetic separation

–      Flotation.

The selection of the best pre-concentration option depends on the ore characteristics and economics. Altrius concluded, based on their assessment, that the pre-concentration techniques potentially most suitable for processing the fine grained copper-gold mineralisation of the Racecourse deposit were, in order of preference:

·    Pre-Screening of run-of-mine ore after blasting and primary crushing, which have shown at some operations to concentrate between 60% and 80% of the target mineralisation into less than 40% to 60% of the feed mass.

·    Gravity Separation via Dense Media Separation (“DMS”), a commonly used and well understood technology. Typically, a DMS circuit would be expected to achieve a mass rejection of approximately 70% with a corresponding valuable mineral recovery of >95%.

·    Coarse Particle Flotation (“CPF”) which consists of the recovery of partially liberated valuable mineral particles following coarse primary grinding. The concept is to reject a portion of barren material at a coarse size, rather than having to grind the entire feed resulting in reduced comminution (milling) costs. CPF has been shown to recover between 92% and 98% of the mineralisation into 6% of the mass for deposits similar to the Racecourse deposit.

In order to evaluate the amenability of the deposit to pre-concentration techniques metallurgical test samples from drill holes BRDD21-036 (168m @ 0.14% Cu & 0.06g/t Au), BRDD22-053 (320m @ 0.11% Cu & 0.06g/t Au) and BRDD21-022 (144m @ 0.25% Cu & 0.02g/t Au) have been dispatched to selected laboratories.

Pre-Screening, Gravity Separation and Coarse Particle Flotation test work has commenced at the individual laboratories and results are expected to be available in 2-3 months.

Further information

Further information is available from the Company’s website which details the Company’s project portfolio as well as a copy of this announcement: www.xtractresources.com


The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under the Market Abuse Regulations (EU) No. 596/2014 as it forms part of UK Domestic Law pursuant to the Market Abuse (Amendment) (EU Exit) regulations (SI 2019/310). The person who arranged for the release of this announcement on behalf of the Company was Colin Bird, Executive Chairman and Director.



Xtract Resources Plc Colin Bird,

Executive Chairman


+44 (0)20 3416 6471


Beaumont Cornish Limited

Nominated Adviser and Joint Broker

Roland Cornish

Michael Cornish

Felicity Geidt

+44 (0)207628 3369



Novum Securities Limited

Joint Broker                  


Jon Belliss

Colin Rowbury 


+44 (0)207 399 9427



Beaumont Cornish Limited (“Beaumont Cornish”) is the Company’s Nominated Adviser and is authorised and regulated by the FCA. Beaumont Cornish’s responsibilities as the Company’s Nominated Adviser, including a responsibility to advise and guide the Company on its responsibilities under the AIM Rules for Companies and AIM Rules for Nominated Advisers, are owed solely to the London Stock Exchange. Beaumont Cornish is not acting for and will not be responsible to any other persons for providing protections afforded to customers of Beaumont Cornish nor for advising them in relation to the proposed arrangements described in this announcement or any matter referred to in it.

Qualified Person

Information in this announcement relating to the exploration works has been reviewed by Edward (Ed) Slowey, BSc, PGeo, a consultant to Xtract. Mr Slowey is a graduate geologist with more than 40 years’ relevant experience in mineral exploration and mining, a founder member of the Institute of Geologists of Ireland and is a Qualified Person under the AIM rules. Mr Slowey has reviewed and approved the geological content of this announcement.

Qualified Person

In accordance with AIM Note for Mining and Oil & Gas Companies, June 2009 (“Guidance Note”), Colin Bird, CC.ENG, FIMMM, South African and UK Certified Mine Manager and Director of Xtract Resources plc, with more than 40 years’ experience mainly in hard rock mining, is the qualified person as defined in the Guidance Note of the London Stock Exchange, who has reviewed the technical information contained in this press release.

Mineral Reserves and Resources

The Company estimates and discloses mineral reserves and resources using the definitions adopted by JORC.  Further details are available at www.jorc.org.  See the “Glossary of Geological and Mining Terms” for complete definitions of mineral reserves and mineral resources.

About Mineral Resources

Mineral resources are not mineral reserves and do not have demonstrated economic viability but do have reasonable prospect for economic extraction.  They fall into three categories: measured, indicated, and inferred. The reported mineral resources are stated inclusive of mineral reserves.  Measured and indicated mineral resources are sufficiently well-defined to allow geological and grade continuity to be reasonably assumed and permit the application of technical and economic parameters in assessing the economic viability of the mineral resource. Inferred mineral resources are estimated on limited information not sufficient to verify geological and grade continuity or to allow technical and economic parameters to be applied.  Inferred mineral resources are too speculative geologically to have economic considerations applied to them. There is no certainty that mineral resources of any category will be upgraded to mineral reserves.

Important Information about Mineral Reserve and Resource Estimates

Whilst the Company takes all reasonable care in the preparation and verification of the mineral reserve and resource figures. the figures are estimates based in part on forward-looking information. Estimates are based on management’s knowledge, mining experience, analysis of drilling results, the quality of available data and management’s best judgment. They are, however, imprecise by nature, may change over time, and include many variables and assumptions including geological interpretation, commodity prices and currency exchange rates, recovery rates, and operating and capital costs. There is no assurance that the indicated levels of metal will be produced, and the Company may have to re-estimate the mineral reserves based on actual production experience. Changes in the metal price, production costs or recovery rates could make it unprofitable to operate or develop a particular deposit for a period of time.


The following is a summary of technical terms:

“Ag” Silver
“Au” Gold
“chalcopyrite” A copper-iron sulphide mineral, CuFeS2, often found in copper ores
“Cu” Copper
“CuEq” Copper equivalent grade, calculated using assumed metal prices for copper, gold and other metals


“Indicated Mineral Resource” That part of a Mineral Resource for which quantity, grade (or quality), densities, shape and physical characteristics are estimated with sufficient confidence to allow the application of Modifying Factors in sufficient detail to support mine planning and evaluation of the economic viability of the deposit. Geological evidence is derived from adequately detailed and reliable exploration, sampling and testing gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes, and is sufficient to assume geological and grade (or quality) continuity between points of observation where data and samples are gathered. (JORC 2012)


“Inferred Mineral Resource” That part of a Mineral Resource for which quantity and grade (or quality) are estimated on the basis of limited geological evidence and sampling. Geological evidence is sufficient to imply but not verify geological and grade (or quality) continuity. It is based on exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. (JORC 2012)


“mineralisation” Process of formation and concentration of elements and their chemical compounds within a mass or body of rock
“Mtpa” Million tonnes per annum
“porphyry” A deposit of disseminated copper minerals in or around a large body of intrusive rock


“pyrite” Iron sulphide mineral, FeS2
“pyrrhotite” An iron sulphide mineral, Fe1-XS, often magnetic


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