AAN.V · 2023-07-28 12:00:00

Aton reports new results from metallurgical testing on Rodruin and Hamama West s ulphide minerali sation

Metallurgy & Processing

FOR IMMEDIATE RELEASE

Aton reports new results from metallurgical testing on

Rodruin and Hamama West s ulphide minerali sation

Vancouver, British Columbia, July 28, 2023: Aton Resources Inc. (AAN: TSX-V) (“Aton” or the “Company") is

pleased to update investors on the results of further preliminary metallurgical testwork from its Rodruin and

Hamama West projects. Rodruin and Hamama West are both located within the Company’s 100% owned Abu

Marawat Concession (“Abu Marawat” or the “Concession”), in the Eastern Desert of Egypt.

Highlights:

• Two composite samples representing the main sulphide mineralisation types at Rodruin underwent

preliminary metallurgical testwork investigating the potential to produce saleable copper and zinc

concentrates. The composite samples were prepared from selected diamond drill half core intervals;

• Results from a locked cycle flotation test carried out on sample ROMS-007 produced a copper

concentrate of 28.1% copper at a recovery of 69.2%, and a zinc concentrate of 61.6% zinc a t a

recovery of 79.6%;

• Sequential flotation tests carried out on the Rodruin sulphide mineralisation types indicate that

potentially saleable copper and zinc concentrates can be achieve d at reasonable metal recoveries

and grades. Both the copper and zinc concentrates contain reasonable gold and silver credits;

• A single bulk composite sample representative of the sulphide mineralisation at Hamama West

underwent metallurgical testwork including cyanidation leach testing and flotation testwork to assess

its amenability to cyanide leaching, and the potential to produce a saleable gold- or gold-silver bearing

concentrate. The composite sample was prepared from selected diamond drill half core intervals and

RC percussion drill chips;

• Whole ore cyanide leach testwork showed that 49.8% of the gold was recoverable by cyanide leaching.

Metal recoveries of 47.1% and 26.1% were also obtained for silver and copper, respectively;

• Rougher flotation optimisation found that 81.2% and 75.7% of gold and silver were recoverable to a

concentrate, at grades of 3.41 g/t gold and 84.8 g/t Ag silver, and at a high mass pull of 25.5% by

weight;

• A bulk sulphide float recovered 85% of the gold and 83% of the silver to a rougher concentrate

assaying 2.98 g/t Au and 94.9 g/t Ag, respectively;

• Bulk concentrate cyanide leach testwork showed that a gold recovery of 54.8% was achievable at a

particle size of 80% passing 10µm. Silver and copper recoveries of 60.3% and 47.0% were achieved,

respectively;

• The Hamama West sulphide mineralisation was not amenable to conventional CIL , no r flotation

followed by ultra -fine grinding /CIL processing routes . A bulk sulphide float produces a potential

precious metals concentrate containing gold and silver credits.

“These preliminary metallurgical testwork results from the Rodruin gold-polymetallic sulphide mineralisation

are most encouraging, and indicate that saleable copper and zinc concentrates can be produced, containing

very respectable gold and silver metal credits . The copper concentrate in particular recovers high grades of

gold and silver, and could potentially be sold as a precious metals concentrate” said Tonno Vahk, Interim CEO.

“The results from testing of the Hamama West sulphide mineralisation were less positive and indicate that the

sulphide mineralisation is refractory, and is not amenable to CIL processing. However high recoveries of gold

and silver to a bulk concentrate indicate that a precious metals concentrate could potentially be produced from

Hamama West, and this could provide Aton with some synergies when processing sulphide material from both

the Hamama West and Rodruin deposits, as well as the higher grade Abu Marawat deposit , which contains

significantly higher copper grades than either Rodruin or Hamama West . In the light of the results from this

phase of metallurgical testwork Aton has decided to defer the immediate work on the revised mineral resource

estimate for the Abu Marawat Concession, as it evaluates a net smelter return approach to the resource

estimation, in order to fully assess the potential of the Hamama West, Rodruin and Abu Marawat gold -silver-

copper-zinc sulphide deposits. The Company is continuing to push ahead towards its immediate primary goal,

which is the completion of its application for the exploitation licence at the Abu Marawat Concession, and plans

to submit this application to the Egyptian Mineral Resources Authority within the coming two months. The

application for the exploitation licence will be based on a ‘commercial discovery’ comprising open pit mine and

heap leach projects on the oxide gold caps of both the Hamama West and Ro druin deposits , which will

represent the first two mining projects in the planned phased development of the Abu Marawat Concession.”

Figure 1: Geological plan of the Rodruin area, showing the main mineralised zones and the

collars of the drill holes sampled in samples ROMS-006 and ROMS-007

Metallurgical testwork programme - Rodruin

Two composite samples were prepared from the Rodruin mineral deposit for metallurgical testing, which were

representative of the two main sulphide mineralisation types, hosted in intensely phyllic altered (“phyllic”) and

carbonate rock types. This preliminary testwork programme was designed to follow on from testing of the oxide

mineralisation types carried out in early 2023, which indicated that the Rodruin oxide mineralisatio n is

amenable to processing using heap leach and conventional CIL technology (see news release dated March

9, 2023). The programme was specifically focused on the sulphide mineralisation at Rodruin to evaluate the

potential of processing both the main sulphide mineralisation types by flotation, with the goal of p roducing

saleable copper and zinc concentrates.

Samples were selected from diamond drill half core intervals (HQ and PQ size), to produce total sample

weights between 40-45kg. 2 samples were composited from the 2 main sulphide mineralisation types ,

specifically phyllic and carbonate hosted mineralisation (see Figure 1). Details of the samples are provided in

Table 1.

Metallurgical

sample ID Drill hole ID’s Mineralisation

type

Sample

weight

Estimated grades 1

(g/t)

(%)

ROMS-006 ROD-071, ROD-

080, ROD-112 Phyllic hosted 40.7 kg 2.33 21.6 0.25 0.03 2.94

ROMS-007 ROD-048, ROD-

091

Carbonate

hosted 44.4 kg 0.58 10.3 0.23 0.02 3.26

Notes:

1) Sample grade estimated from the weighted average assays of the sampled drill core intervals

Table 1: Details of the Rodruin sulphide metallurgical samples

The diamond drill half core samples were dispatched from Egypt to Wardell Armstrong International Ltd (“WAI”)

in December 2022, for metallurgical testing at their laboratory located in Cornwall, UK, with testwork

commencing in January 2023. The half core intervals were combined to prepare 2 composite samples, which

underwent a process evaluation testwork program me consisting of head assay s, XRD analysis, rougher,

cleaner and locked cycle flotation testing.

Head assays

Sub-samples of the 2 composite metallurgical samples were sent by WAI for head assay analysis at ALS

Minerals’ geochemical laboratory at Loughrea, Ireland, and were analysed for Au ( by screen fire assay), Ag,

Cu, Pb, Zn, As, Fe and S. Additional analysis for deleterious elements was not undertaken, but this additional

analytical work is planned. The results of the head assays are provided below in Table 2:

Head assay results Estimated

Au grade

(g/t) 2

Metallurgical

sample ID

Assay (g/t) Assay (%)

Au 1 Ag Cu Pb Zn As Fe S

ROMO-006 2.31 24.5 0.22 0.02 2.52 0.04 4.8 12.2 2.33

ROMO-007 0.55 10.5 0.25 0.02 3.33 0.01 9.3 >10.0 0.58

Notes:

1) Au by screen fire assay (ALS Minerals. Loughrea, Ireland)

2) Sample grade estimated from the weighted average assays of the sampled drill core intervals

Table 2: Head assay results

The Au head assays measured by screen fire assay show good correlation with the estimated grade of the

composited drill core samples (Table 2). Ag, Cu, Pb and Zn head assays also showed good correlation with

the estimated grades of the composite samples.

The good correlation in assay results indicate s that the composite d samples prepared for metallurgical

testwork are representative of the drill core intervals sampled.

Mineralogical analysis

The XRD results showed the samples as being gangue dominated. The phyllic hosted ROMS-006 composite

sample is predominantly composed of quartz, phyllosilicate minerals (chlorite, illite, mica) and pyrite. The

carbonate hosted ROMS -007 composite sample contained a mixture of dolomite, talc, quartz and pyrite.

Sphalerite occurs as a minor but significant constituent of both samples.

The results of the XRD analysis are shown in Figure 2:

Figure 2: Results of XRD analysis

Flotation testwork - Rodruin

Rougher optimisation tests

The two sulphide samples were subjected to flotation testing to investigate the potential to recover base metal

concentrates from the sulphide mineralisation.

The flotation route tested involved sequential copper and zinc flotation. A primary grind size of 80% passing

75μm was utilised for rougher flotation optimi sation, except for ROMS -006 FT3 where a grind size of 80%

passing 53µm was used. Results are summarised in Table 3.

Table 3: Optimal rougher flotation test results

Rougher optimisation testwork showed optimum copper and zinc recoveries to concentrates from the ROMS-

006 sample were 87.9% at a grade of 2.32% copper, and 62.6% at a grade of 16.0% zinc , respectively. For

the ROMS-007 sample optimum flotation performance achieved recoveries of 87.4% at a grade of 3.54%

copper, and 91.5% at grade of 9.95% zinc, respectively.

Sample

ID Test Product

Mass

pull

(%)

Grade Recovery (%)

(%)

(g/t)

STOT

(%) Cu Zn Au Ag STOT

ROMS-006 FT1

Cu Ro conc. 8.87 2.32 10.3 17.8 37.7 23.5 87.9 35.1 66.7 74.2 56.2

Zn Ro conc. 10.1 0.16 16.0 3.78 32.7 22.0 6.86 62.6 16.1 15.6 37.5

ROMS-007 FT3

Cu Ro conc. 6.04 3.54 2.23 5.04 89.8 36.5 87.4 3.95 53.9 55.0 19.3

Zn Ro conc. 31.4 0.07 9.95 0.59 9.98 29.2 9.61 91.5 32.6 31.8 80.3

Open cycle cleaner tests

A series of open circuit cleaner flotation tests were subsequently conducted based upon the optimum rougher

flotation conditions. A summary of the optimum open circuit results is provided in Table 4.

Sample

ID Test Product

Mass

pull

(%)

Grade Recovery (%)

(%)

(g/t)

STOT

(%) Cu Zn Au Ag STOT

ROMS-

006

FCT

Cu Cl 3 conc. 0.50 32.3 9.17 103 1,512 32.9 54.0 1.65 19.5 28.5 2.45

Zn Cl 3 conc. 3.30 0.36 52.2 3.29 52.5 34.7 4.07 63.9 4.23 6.70 17.5

ROMS-

007

FCT

Cu Cl 3 conc. 0.31 34.9 3.24 32.4 1,012 33.3 42.4 0.30 17.7 31.1 0.92

Zn Cl 3 conc. 4.45 0.17 50.3 0.60 23.3 33.6 3.08 67.3 4.76 10.4 13.5

Table 4: Open cycle cleaner test results

Three-stage open circuit cleaner optimisation testwork demonstrated that for sample ROMS-006, final

concentrate grades of 32.3% copper at a recovery of 54.0%, and 52.2% zinc at recovery of 63.9% could be

achieved, respectively. Furthermore, gold and silver were recovered to the final copper concentrate at grades

of 103 g/t Au and 1,512 g/t Ag, respectively.

The same three -stage cleaning conditions were utilised for sample ROM -007, from which final concentrate

grades of 34.9% Cu at a recovery of 42.4%, and 50.3% Zn at a recovery of 67.3% were achieved, respectively.

Gold and silver were recovered to the final copper concentrate at grades of 32.4 g/t Au and 1,012 g/t Ag,

respectively.

Locked cycle tests

A single locked cycle test was carried out on the ROMS-007 sample, as the predominant lithology of the two

sulphide mineralisation samples, based on the test conditions used in the FCT5 open cycle cleaner test . A

summary of the flotation performance as an average of the final three cycles is shown in Table 5.

Product

cycle Cycle

Mass

pull

(%)

Assay Distribution (%)

(%)

(g/t)

STOT

(%) Cu Zn Au Ag STOT

Cu Cl concentrate 4-6 0.6 28.1 4.20 30.9 659 32.5 69.2 0.73 31.5 38.3 1.68

Zn Cl concentrate 4-6 4.4 0.25 61.6 0.97 28.2 32.8 4.52 79.6 7.33 12.2 12.6

Final tailings 4-6 95.0 0.07 0.71 0.38 5.32 10.4 26.3 19.6 61.2 49.5 85.7

Feed 4-6 100.0 0.24 3.41 0.58 10.2 11.5 100 100 100 100 100

Table 5: Locked cycle test results

Results from the locked cycle flotation test carried out on ROMS-007 showed that a copper concentrate grading

28.1% Cu at a recovery of 69.2%, and a zinc concentrate grading 61.6% Zn at a recovery of 79.6% could be

produced. Gold and silver were recovered to the final copper concentrate at grades of 30.9 g/t Au and 659 g/t

Ag, respectively. Both the copper and zinc concentrates contain reasonable levels of gold and silver credits.

Discussion of results

The gold head assays reported by ALS correlate well with the estimated composite sample grades, calculated

from the weighted diamond drill hole assays, and indicate that the composite metallurgical samples are

representative of the sampled intervals.

The mineralogical (SEM, XRD) analysis confirms geological interpretation that the samples can be sub-divided

into two broad categories of mineralisation, as follows:

• Sample ROM S-006 represents phyllic hosted mineralisation, and is mainly composed of quartz,

phyllosilicate minerals (chlorite, illite, mica) and pyrite. This sample is representative of the higher

grade gold-polymetallic mineralisation intersected in holes ROD-071 (see news release dated May 10,

2022), ROD-075 (see news release dated June 1, 2022), and also the lower zone of mineralisation in

hole ROD-117 (see news release dated December 20, 2022).

• Samples ROMS-007 represents carbonate hosted mineralisation, and is predominantly composed of

dolomite, talc, quartz and pyrite. This sample is representative of the carbonate hosted mineralisation

intersected in holes ROP -050 (see news release dated January 29, 2019 ), and the upper zone of

mineralisation in hole ROD-117 (see news release dated December 20, 2022).

Results of the locked cycle test indicate that saleable copper and zinc concentrates can potentially be produced

with reasonable gold and silver credits.

Based on the open cycle cleaner test results , other final copper and zinc cleaner products which would be

acceptable saleable concentrates, as shown in Table 6, could be considered.

Sample ID Test Product

Mass

pull

(%)

Grade Recovery (%)

(%)

(g/t)

STOT

(%) Cu Zn Au Ag STOT

ROMS-006 FCT9

Cu Cl 2 conc. 0.8 24.0 11.7 93.7 1,283 33.9 65.7 3.5 29.0 39.5 4.1

Zn Cl 2 conc. 3.9 0.4 49.3 4.2 61.6 35.4 5.4 72.3 6.4 9.4 21.4

ROMS-007 FCT5

Cu Cl 1 conc. 0.8 22.9 4.6 25.0 577 30.6 71.8 1.1 35.1 45.7 2.2

Zn Cl 3 conc. 4.45 0.17 50.3 0.60 23.3 33.6 3.08 67.3 4.76 10.4 13.5

Table 6: Open cycle cleaner test results

Figure 3: Hamama West drill hole collar plan, indicating the holes sampled for the bulk composite

sample HAMS-01

Metallurgical testwork programme – Hamama West

A single composite sample representative of the sulphide mineralisation at the Hamama West mineral deposit

was prepared for metallurgical testing. This preliminary testwork programme was designed to follow up on

testing of the oxide mineralisation types carried out in 2017 -18 (see news release dated February 22, 2018),

which indicated that the Hamama West oxide mineralisation is amenable to processing using heap leach and

conventional CIL technology. The new phase of testwork was focused on the sulphide mineralisation at

Hamama West to evaluate its potential amenability to cyanide leaching, and the potential of flotation methods

to produce a saleable gold-bearing, or a gold and silver-bearing precious metals concentrate.

A bulk composite sample, HAMS-01, was collected from a combination of diamond drill half core intervals (HQ

and PQ size, 10 holes), and RC percussion drill chips (5 holes ) to produce a total sample weight of 88.6 kg

(see Table 7). The holes sampled were spread out along the strike length and the entire vertical extent of the

sulphide mineralisation at Hamama West (Figure 3).

Metallurgical

sample ID Drill hole ID’s Zone Mineralisation

type

Estimated

grades1

Au (g/t) Ag (g/t)

HAMS-01

AHA-024, AHA-026, AHA-044, AHA-058,

AHA-061, AHA-067, HAD-002, HAD-004,

HAD-005, HAD-010, HAP-147, HAP-157,

HAP-193, HAP-195, HAP-199

Hamama

West (Main

Zone)

Sulphide 0.82 28.62

Notes:

1) Sample grade estimated from the weighted average assays of the sampled drill core and RC percussion chip intervals

Table 7: Details of the HAMS-01 bulk composite metallurgical sample

The HAMS-01 diamond half core and RC percussion chip samples were also dispatched from Egypt to WAI

in December 2022, for metallurgical testing at their laboratory located in Cornwall, UK, with testwork

commencing in January 2023. The half core intervals and RC percussion chips were composited in order to

prepare 2 composite sub-samples, which underwent a process evaluation testwork programme consisting of

head assays, diagnostic leach test, rougher and cleaner flotation testing, and bulk sulphide flotation, followed

by ultra-fine grinding and bottle roll cyanide leach testing.

Head assays

A sub-sample of the HAMS-01 metallurgical composite sample was sent by WAI for head assay analysis at

ALS Minerals’ geochemical laboratory at Loughrea, Ireland, and w as analysed for Au (by screen fire assay),

Ag, Cu and S. Additional analysis for deleterious elements was not undertaken, but this additional analytical

work is planned. The results of the head assays are provided below in Table 8:

Metallurgical

sample ID

Assay (ppm) Assay (%) Estimated grades 2

Au 1 Ag Cu S Au (g/t) Ag (g/t)

HAMS-01 0.94 29.26 0.021 3.01 0.82 28.62

Notes:

1) Au by screen fire assay (ALS Minerals. Loughrea, Ireland)

2) Sample grade estimated from the weighted average assays of the sampled drill intervals

Table 8: Head assay results

The Au and Ag head assays show good correlation with the estimated Au and Ag grades of the composited

drill core and RC samples (Table 2 above).

The correlation in assay results indicates that the HAMS-01 bulk composite sample prepared for metallurgical

testwork is representative of the drill core and RC percussion chip intervals sampled.

Flotation testwork – Hamama West

Rougher optimisation tests

A series of rougher flotation tests were conducted on the HAMS-01 sample to optimise suitable conditions for

gold and silver recovery by means of sulphide flotation. Results of the rougher optimisation tests are shown in

Table 9.

Table 9: Rougher optimisation test results

Gold grades in the rougher optimisation concentrates ranged from 2.66 g/t to 3.41 g/t gold, for tests FT3 and

FT1, respectively. Silver grades ranged from 80.3 g/t to 92.4 g/t, for tests FT2 and FT3, respectively.

Open cycle cleaner tests

A single cleaner test was carried out to determine the sample’s amenability to increas ing the flotation

concentrate gold and silver grades. Results of the open cycle cleaner test results are shown in Table 10.

Product Mass pull

(%)

Assay Recovery Assay Recovery

Au (g/t) Au (%) Ag (g/t) Ag (%)

FCT1 Ro conc. 25.1 2.75 82.2 94.4 81.0

FCT1 Cl conc. 1 20.9 2.95 73.6 101.1 72.4

FCT1 Cl conc. 2 19.3 3.08 71.0 105.7 69.8

Table 10: Open cycle cleaner test results

Final open circuit cleaner concentrate gold and silver assays indicate minimal upgrading of the material from

2.75 g/t to 3.08 g/t gold, and 94.4 g/t to 105.7 g/t silver, respectively. Based on results of the open cycle cleaner

test exploring the production of a saleable gold concentrate was abandoned.

Bulk sulphide float test

A bulk sulphide flotation test was carried out to produce bulk rougher concentrate for cyanidation leach

testwork. Results of the bulk sulphide float test are summarised in Table 11.

Table 11: Bulk sulphide flotation test results

The results shown in Table 11 indicate that 85.0% and 83.1% of the gold and silver were recovered to the bulk

sulphide concentrate assaying 2.98 g/t gold and 94.9 g/t silver, respectively.

Product Mass pull

(%)

Residence

time (mins)

Assay Recovery Assay Recovery

Au (g/t) Au (%) Ag (g/t) Ag (%)

FT1 final Ro conc. 25.5 15 3.41 81.2 84.8 75.7

FT2 final Ro conc. 16.5 15 2.80 53.5 80.3 50.1

FT3 final Ro conc. 21.3 15 2.66 70.2 92.4 69.9

Product Mass pull

(%)

Assay Distribution (%)

(ppm)

(%)

STOT

(%) Au Ag Cu STOT

BFT1 Ro conc. 24.9 2.7 94.8 0.1 27.7 82.6 82.3 78.6 90.7

BFT1 Ro tails 75.1 0.2 6.8 0.0 0.94 17.4 17.7 21.4 9.3

BFT1 feed 100 0.83 28.7 0.0 7.61 82.6 100 100 100

BFT2 Ro conc. 26.0 2.9 88.6 0.1 27.3 86.0 82.9 83.1 90.1

BFT2 Ro tails 74.0 0.2 6.4 0.0 1.0 14.0 17.1 16.9 9.9

BFT2 feed 100 0.9 27.7 0.0 7.9 100 100 100 100

Blended Ro conc. 25.4 2.98 94.9 0.09 27.7 85.0 83.1 81.6 90.5

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