Western Australia – Gascoyne 

Graphite Bull

Overview

The Graphite Bull Project is located 280km East of Carnarvon, Western Australia, and covers an area of 22km(Figure 1). Buxton have undertaken a range of exploration and resource development programs at Graphite Bull including geological mapping, EM surveys, flora, fauna & heritage assessments, several rounds of drilling, petrology, two resource estimates and metallurgy test work.

Figure 1. Regional location of Graphite Bull tenement, E09/1985

 

 

Geology and Exploration Model

The Graphite Bull Project is located between the Yilgarn Block and the Gascoyne Province where Archaean rocks have undergone deformation and metamorphism during Lower Proterozoic orogenesis. The Archaean rock types comprise gneisses, amphibolites, granofels, quartzites and iron formations. The Graphite Bull mineralisation is characterised as multiple, very high-grade bands of graphite schist hosted within gneissic rocks of intermediate composition. The licence is considered prospective for graphite and gold mineralisation.

Elements that define Graphite Bull as a quality development-stage Project include;

  • Tier 1 jurisdiction
  • High grade, thick mineralisation 
  • Shallow, ideal for open pit mining 
  • Excellent continuity
  • Flotation produces >95% TGC concentrate

In 2013, the Company completed a 15 hole RC drilling program for 1,674m. This work confirmed that very high-grade graphite occurs within multiple zones over a minimum 500m strike length.  Assays results included;

YBRC001   32m @ 23.4% TGC inc. 7m @ 32.6% TGC

YBRC002   14m @ 22.3% TGC inc. 6m @ 26.8% TGC

YBRC011   14m @ 21.5% TGC inc. 5m @ 33.0% TGC

YBRC012   31m @ 22.9% TGC inc. 5m @ 30.2% TGC

YBRC015   31m @ 22.5% TGC inc. 6m @ 33.0% TGC

These are among the highest grade and thickness graphite drill intercepts reported in Australia.

In February 2014, Buxton announced a maiden, very high-grade JORC 2012 compliant Inferred graphite resource estimate of 2.27Mt @ 20.1% TGC using a 10% TGC cut-off.

In July 2014, Buxton completed a combined RC and Diamond drilling program of 17 holes for 2476m Graphite Bull.  An updated JORC compliant Inferred Mineral Resource Estimate was calculated at 4.0Mt @ 16.2% TGC, using a 4% TGC cut-off. 

In 2023, Buxton completed ground EM surveys followed by a 5-hole RC drilling program for 991m.

This work confirmed that high grade graphite mineralisation extends for at least 2kms along strike and a new zone of mineralisation was discovered at shallow depths in the hangingwall to the existing resource (Figure 2). Significant intersections from this program included; 

GB001RC 33m @ 18% TGC

GB003RC 18m @ 16.2% TGC

GB004RC 32m @ 17.7% TGC inc. 5m @ 24.7% TGC

GB005RC 5m @ 24.5% TGC

Buxton will be progressing resource infill and expansion, along with metallurgical studies in the short term.

Continuing metallurgical studies have focused on delivering a simplified, low-cost flowsheet for producing concentrate suitable for Battery Anode Material production.  Buxton has seen exceptional results from this work, including;

  • Flotation producing >95% TGC concentrate at recoveries up to 93.7%
  • Concentrate grades >98% TGC achieved from flotation alone

These results confirm Graphite Bull as one of Australia’s highest quality graphite projects.  Metallurgical work is now progressing to Battery Anode Amenability testwork by experienced laboratories in Germany.  This work is aimed at defining Graphite Bull as Australia’s preeminent graphite supplier.

 

 

 

Figure 2. Plan view of E09/1985 showing recent drill hole locations in reference to the existing JORC inferred resource. Mineralisation in holes GB001RC – GB005 RC allow interpretation of continuous mineralisation along strike and GB001RC indicates a new graphitic zone.

 

 

 

The 2023 RC drill program intersected a new shallow zone of graphite mineralisation located south of the known JORC resource. The cross section (Figure 3) shows that this zone was not modeled due to the configuration of recent ground EM surveying.

Alongside a newly discovered graphitic zone, holes GB004RC and GB005RC, the two largest step out holes from the defined resource, both returned exceptional intercepts of high grade graphitic mineralisation. This provides categorical evidence that graphite mineralisation occurs across at least 2.0km of strike which remains open, including at depth.

This newly identified zone will be further explored in the 2023 field season as Buxton looks to expand the scale of Graphite Bull.

 

 

 

Figure 3. Cross section of drill hole GB001RC (looking west) showing the newly discovered shallow graphitic zone which was not detected by recent moving loop ground EM (blue plates).

 

 

 

 

Petrographic work has confirmed that a significant portion of the graphite exists as medium to coarse flakes within high-grade microbands. Observations show that graphite flakes generally range from 100 to 500 microns long and in some cases reach over 1mm in length.

 

 

Figure 4. Microphotograph of Graphite Bull mineralisation.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2012: VTEM
Company: Geotech Airborne for Buxton Resources
Description/Results: 376-line kms, 100m line spacing, VTEMplus (MAGIX R70885) defined highly conductive graphitic units.

24th Jan 2013: Tenement Granted
Company: Montezuma Mining Company Ltd
Description/Results: Exploration licence E09/1985 granted for an initial term of 5 years.

2013 & 2014: Mapping, Surface Geochemistry
Company: Field mapping and rock chip sampling. Buxton Resources
Description/Results: Substantial and widespread high-grade graphite mineralisation defined at surface.

Nov 2013: RC Drilling
Company: 15 holes for 1,674m
Description/Results: Significant zones of high-grade graphite intersected in most holes.

Dec 2013: Petrology
Company: 2 thin sections and 4 polished blocks
Description/Results: High proportion of graphite flakes in the 200 to 500µm range, occurring in a finer grained graphitic matrix.

Feb 2014: Resource Estimate
Company: JORC compliant Mineral Resource Estimate completed by CSA Global for Buxton Resources
Description/Results: Inferred JORC Resource of 2.3Mt @ 20.1% TGC (0% TGC cut-off).

Jul-Aug 2014: RC and DD Drilling
Company: 17 holes for 2,476m, Quality Drilling Services & Topdrive Drillers for Buxton Resources
Description/Results: Extensions and infill to main resource area. Diamond core collected for additional structural/geological information and metallurgical purposes.

Sep 2014: Petrology
Company: 6 polished sections
Description/Results: Graphite rich portions of samples had grainsizes above the commercial definition of coarse flake (>150µm).

Oct 2014: Resource Estimate
Company: JORC compliant Mineral Resource Estimate completed by CSA Global for Buxton Resources
Description/Results: Inferred JORC Resource of 4.0Mt @ 16.2% TGC (4% TGC cut-off).

Aug 2015: Metallurgy
Company: Scoping level evaluation of two composite samples (fresh and saprolite). SGS Mineral Services Canada for Buxton Resources
Description/Results: Commercial grade products produced. Preliminary flotation returned concentrate grades of 91-92% C(t) with a good proportion of medium to coarse flake. Final leach upgrades concentrate to 99% C(t).

Mar 2016: Tenement Ownership Transfer
Company: Buxton Resources acquired residual interest in Graphite Bull from Montezuma Mining
Description/Results: Buxton issues 4,000,000 unlisted options (expiry 31/03/2019, exercise price 12.5c) together with a 0.75% gross revenue royalty for consideration of acquiring 15% of E09/1985, taking Buxton’s ownership to 100%.

2016-2018: Commercial negotiations and market studies
Company: Buxton
Description/Results: During this period Buxton fielded many enquiries as the potential divestment of the Graphite Bull Project which required review. Buxton also undertook market studies which resulted in the realisation of the potential for Graphite Bull to supply purified spherical graphite (PSG) products, rather than flake graphite products – requiring a fundamental change in the technical approach to evaluating the deposit.

2019 – 2022: Metallurgy – Caustic Bake sighter testwork
Company: Buxton / Elmore Ltd
Description/Results: Sighter testwork by Elmore Ltd has indicated that the Graphite Bull graphite deposit could be amenable to a simplified, low-cost metallurgical flowsheet utilizing a caustic bake stage aimed at improving both recoveries and grade of PSG feed products.

2022: Metallurgy – Composite Sample Preparation
Company: Buxton / ALS
Description/Results: A 132.7 kg sample was composited from selected intervals in diamond hole YBDD002. ALS crushed and blended the sample to 100% passing 3.35 mm, conducted head assays and prepared splits for subsequent test work.

Activity: Natural Groundwater Chemistry
Company: Buxton
Description/Results: An airlift kit supplied by Pennington Scott Pty Ltd was used to collect water samples, Standing Water Level data, and airlift yields from Buxton drillholes. Most of these drillholes were found to have collapsed around the water table level. Seven natural groundwater samples were collected including three from nearby stock water bores. The samples were analysed by ALS Environmental in Perth.

Activity: Conductivity Physical Property Testwork
Company: Buxton / Southern Geoscience
Description/Results: This work was undertaken to assess the viability of ground EM surveys as a meaningful targeting tool. Nine diamond drill core samples from YBDD002 and YBRD020 were selected with TGC grades spanning 0.6% to 29.9%. These samples were analysed using a KT20 handheld instrument.

Activity: Heritage Agreement Assignment
Company: Buxton / Wajarri Yamaji Aboriginal Corporation
Description/Results: There was a change of aboriginal representative body from YMAC to WYAC. Buxton established relations with WYAC and ratified the validity of the previous heritage agreement.

Activity: Heritage Survey
Company: Buxton / WYAC / Archaeological Excavations Pty Ltd
Description/Results: Heritage Clearance Survey to support infill and extensional drilling activities over 31 hectares. The results were not available at the time this Renewal Application Report was finalised.

Activity: pXRF analysis of drillhole pulps
Company: Buxton
Description/Results: Analysis of 2,180 DD and RC pulps using Olympus Vanta pXRF. After accounting for QA samples, a total of 1,922 multielement assays of drill intervals were collected (82% of the drill database). This data will be used to develop a litho-geochemical classification of the deposit to support future remodeling and assess metallurgical representivity.

Activity: Miscellaneous license applications
Company: Buxton
Description/Results: L09/102 and L09/103 were lodged to support critical infrastructure for a planned mining operation including groundwater search and an access track (respectively).

Activity: Infill and Extensional Drill Planning
Company: Buxton
Description/Results: A review of the existing resource and drillhole database resulted in a provisional drillhole program design of approximately 3000 m of RC drilling. A PoW was submitted to cover 51 hectares (registration ID 110713).

2022 – 2023:
Activity: Metallurgy – Graphite Beneficiation Amenability Testwork
Company: Buxton / ALS, IMO, Battery Limits
Description/Results: This work investigated the relationship between particle size, grades and recovery, aiming to maximise concentrate grades and recoveries. The splits from ALS were tested by two separate metallurgical consultants (IMO and Battery Limits) in parallel.

Jan 2023: MLEM Survey
Company: Buxton / Southern Geoscience / Wireline Services Group
Description/Results: Buxton undertook a Moving Loop EM survey and a fixed loop survey over the main resource area and along-strike extensions as defined by VTEM anomalism. 4th of Jan to the 18th Jan.
Moving loop production averaged 10.8 stations per day, fixed loop averaged 51.5 stations a day, 115 stations fixed loop. Fixed loop
100x100m lines and stations, 2 loops that were 550m x 400m.
The moving loop survey consisted of a total of 75 stations on a 200 m x 200 m grid, using 200m x 200m loops covering 3 km2.

Feb 2023: RC Drilling
Description/Results: The drilling program confirmed the reliability of EM by intersecting graphite in all five holes. RC drilling program was undertaken in February 2023 to test exploration targets based on Moving Loop and Fixed Loop EM surveys flown in January 2023 and define additional zones for resource extensional drilling. 5 wide spaced holes were drilled with a total depth of 998
metres and all five of them intersected graphite confirming that EM is a reliable indicator of graphite mineralisation. It implies a potential to
expand the resource base at Graphite Bull considering several zones of thick and high-grade graphite mineralisation (10m thick dominated by > 10% visually estimated TGC).

2023: Desktop study
Description/Results: A desktop study and market analysis were undertaken by Buxton Resources to get an insight into how Buxton can take the Graphite concentrate a step further into value adding chain and manufacturing. The study was done by CPC Engineering.

2023: Loupe TEM survey
Description/Results: A Loupe TEM survey was undertaken by Buxton Resources to investigate the suitability of Loupe method to expand mapped mineralised zones and improve the resolution of conductivity mapping in top 50 metres of the subsurface. The survey covered an area of approx. 4.0 km X 0.8 km for a total of 56.5 line kilometers of new EM data acquisition with a line spacing of 50 m. In the far west, line spacing was 100 m. Interpretation of Loupe data identified conductive zones adjacent to the existing resource, in the footwall (North) of the existing resource, along strike from the existing resource and in a large area in South West which was not identified by previous EM survey.
As graphite is the only conductive geological material in the Graphite Bull project area, the EM anomalies most likely represent graphite mineralisation in the area.

 

 

 

 

 

 

Maps and Figures