Xanadu Mines Ltd (ASX: XAM, TSX: XAM)
(
Xanadu, XAM or the
Company) is
pleased to provide an update on metallurgical testwork for the
Kharmagtai Copper-Gold Project (
Kharmagtai) in
Mongolia, being developed with the Company’s joint venture partner,
Zijin Mining Group Co., Ltd. (Zijin).
The Eriez HydroFloat test work for evaluating
coarse ore flotation has demonstrated excellent results for one of
the key uplift scenarios defined in the Kharmagtai Scoping Study1.
It has effectively improved upfront processing efficiencies,
producing a coarse reject of up to ~44% by mass for the main
mineralised sulphide orebody.
Highlights
-
Testwork for assessing coarser grind options (P80 grind sizes
ranging between 150 to 450 microns (µm) for
Kharmagtai sulphide mineralisation, using HydroFloat achieved
compelling results:
-
Up to 94% copper and 92% gold recovered in the
HydroFloat stage;
-
Enabling a peak coarse reject of 43.8% by mass, at
450µm; and
-
Rougher recoveries of 91% for copper and 83% for
gold, at 250 µm.
-
Coarse ore flotation may offer numerous benefits for Kharmagtai,
including:
-
Reduced power and water intensity per tonne of ore processed;
-
Increased mill capacity and overall plant capacity for an increased
production rate;
-
Reduction in consumables, such as grinding media and reagents;
and
-
Significant improvement in tailings stability with the production
of coarser tails, as well as water recycling at the back end of the
plant.
-
HydroFloat provides the opportunity for Kharmagtai to recover
valuable minerals in the 150 to 200µm range that processing through
conventional flotation alone is unable to perform.
-
More than 70 HydroFloat units are commercially used in global
operations, including Australia. The pilot program to date has
demonstrated significant potential for HydroFloat, with further
mineralogy and pilot tests to be conducted as new samples become
available.
Xanadu’s Executive Chairman and Managing Director, Colin
Moorhead said:
“These results provide strong support for our
Scoping Study uplift scenario using coarse ore flotation to improve
overall project economics. This uplift is achieved through
increasing throughput and accelerating mining and processing rates
which ultimately accelerate revenue generation at Kharmagtai.
It also promises to enhance the environmental
sustainability aspects of Kharmagtai through the early separation
of barren material and a coarser grind size, allowing for
significant reduction in power and water requirements, and better
tailings management. Given this separation method has been used
successfully by bulk miners for over 20 years, we intend to
leverage those learnings at Kharmagtai. We are now working with
DRA, our process design engineers, to determine the optimal timing
to include HydroFloat in the processing flowsheet, and maximise its
beneficial impact for Kharmagtai.”
Coarse Ore Flotation Metallurgical
Testwork Program
Summary
The existing conventional flowsheet
involves crushing and grinding ore to a P80 size of 150µm for Stage
1 (15Mtpa in Scoping Study) and 212µm for Stage 2 (30Mtpa in
Scoping Study)2.
Testwork to investigate coarser grind options
was completed at ALS’ laboratory in Perth and was supervised by
Eriez Australia using Eriez HydroFloat pilot equipment, returning
HydroFloat rougher recoveries of:
-
91% Cu recovery and 83.2% Au
recovery at 250µm; and
-
88.4% Cu recovery and 77.7% Au
recovery at 350µm.
Description
Composite samples were prepared from core
drilled at each of the Stockwork Hill, White Hill and Copper Hill
deposits Kharmagtai. Sample preparation consisted of combining
samples “as received” into a single 200kg composite, crushing to
3.35mm, followed by rotary blending and splitting and then grinding
individual samples to 150 (finer), 250, 350 and 450 (coarser)
µm.
Eriez supplied the CrossFlow classifier (XF),
rotary drum and HydroFloat (HF) units used for laboratory testing
at the ALS facility. The Eriez Laboratory CrossFlow is a hydraulic
classifier that separates particles according to size, shape, and
specific gravity. Samples were classified in the CrossFlow to
remove the fines and slimes with a target split size of 90µm and
the CrossFlow underflow was used as the feed for the coarse
particle flotation into the HydroFloat unit. Prior to that, the
HydroFloat feed was polished and conditioned with collector reagent
in a rotating drum before being pumped into the HydroFloat. The
entire HydroFloat overflow and HydroFloat underflow streams were
collected, split, and sub-sampled before assay analysis for
primarily copper and gold. Combined CrossFlow overflow and
HydroFloat overflow from the 250 and 350µm tests were tested by
flotation to produce a rougher concentrate, after grinding to
75µm.
HydroFloat Results
The coarse ore flotation evaluation included
head grade analysis and rougher flotation recovery testwork on a
composite sample taken from varying deposits, depths, sulphide and
alteration types to test coarser grind options. Results for the
Cross Flow (XF) stage at the tested P80 grind sizes are shown in
Table 1.
Table 1: Mass Split in Cross
Flow
Stream |
P80 450 µm |
P80 350 µm |
P80 250 µm |
P80 150 µm |
XF Overflow %Wt |
36.6 |
37.6 |
44.5 |
52.9 |
XF Underflow %Wt |
63.4 |
62.4 |
55.5 |
47.1 |
As the grind size gets coarser, less fines are
produced and hence the XF overflow mass reduces from 52.9% by
weight at 150 µm, to 36.6% at 450 µm. In a full-scale flowsheet,
the XF overflow would join the HF overflow for downstream
conventional rougher and cleaner flotation.
The results from the HydroFloat (HF) stage are
shown in Table 2. Both Cu and Au recoveries increase as the grind
size becomes finer, and at the same time the HydroFloat overflow Cu
and Au grades increase from 0.88% Cu to 1.24% Cu and from
0.97g/t Au to 1.70g/t Au, demonstrating improved
liberation at the finer sizes. The HydroFloat underflow grade
(final tailings) reduce from 0.08% Cu to 0.03% Cu and 0.08g/t Au to
0.06g/t Au as the sizing gets finer.
Table 2: HydroFloat Recovery and Mass
Pull Results
Stream |
Parameter |
P80 Grind Size |
450µm |
350µm |
250µm |
150µm |
HF Feed |
% Cu |
0.33 |
0.32 |
0.35 |
0.38 |
g/t Au |
0.35 |
0.25 |
0.40 |
0.54 |
HF Overflow |
%Wt |
30.6 |
32.1 |
33.6 |
28.9 |
% Cu |
0.88 |
0.88 |
0.98 |
1.24 |
g/t Au |
0.86 |
0.65 |
0.98 |
1.70 |
Recovery |
% Cu |
82.9 |
87.3 |
92.5 |
94.4 |
% Au |
84.2 |
77.5 |
90.8 |
92.1 |
HF Underflow |
% Cu |
0.08 |
0.06 |
0.04 |
0.03 |
g/t Au |
0.08 |
0.09 |
0.05 |
0.06 |
The combined XF overflow (minus 90 µm) and the
HydroFloat overflow represent the downstream feed in the process
flowsheet. For each of the 250 µm and 350 µm laboratory tests, the
XF and HF overflows were combined and ground to 75 µm for rougher
flotation. The results of this step, plus the HydroFloat (HF)
results are combined in Table 3 and compared with results from the
conventional flowsheet.
Table 3: Combined Results of HydroFloat
Test Products for Rougher Flotation Compared to Standard
Rougher Test
Product |
350µm HF Feed and 75 µm
Rougher |
250µm HF Feed and 75 µm
Rougher |
Typical conventionalResults |
|
Cu% |
Cu Rec% |
Au g/t |
Au Rec% |
Cu% |
Cu Rec % |
Au g/t |
Au Rec % |
Cu% |
Cu Rec% |
Au g/t |
Au Rec% |
Rougher Concentrate |
6.11 |
88.4 |
4.51 |
77.7 |
5.95 |
91.0 |
4.07 |
83.2 |
4.64 |
90.1 |
4.50 |
86.4 |
Rougher Tailings |
0.04 |
5.5 |
0.08 |
11.4 |
0.04 |
5.4 |
0.06 |
10.8 |
0.04 |
9.9 |
0.06 |
13.6 |
XF Underflow |
0.06 |
6.1 |
0.09 |
10.9 |
0.04 |
3.6 |
0.05 |
6.0 |
- |
- |
- |
- |
These results demonstrate that the 250 µm HydroFloat test,
followed by a 75 µm grind for rougher flotation, produced similar
results to a conventional flotation test at 150 µm. Furthermore,
improved rougher concentrate grade and recovery were achieved:
- 5.95% Cu grade and
91.0% recovery for HydroFloat, versus
- 4.64% Cu grade and
90.1% recovery for conventional flotation.
However, Au grade and recovery are both less favourable for
HydroFloat versus conventional flotation.
Results indicate that use of Eriez HydroFloat for
Kharmagtai ore achieved a high recovery while rejecting coarse,
barren ore.
Significance to Kharmagtai
The results achieved in these preliminary tests provide
sufficient encouragement to conduct further studies. Since the
comminution circuit is the major source of energy consumption,
investigating ways to reduce this through a coarser grind warrants
further work. This will take the form of mineralogical studies to
determine the liberation of sulphides at coarse grinds, followed by
further pilot testing on new samples, as they become available.
Figure 1: Eriez 6” Laboratory HydroFloat
Setup
Sample Selection and
Preparation
Metallurgical sample locations, zones and
assayed head grades are detailed in Table 3. Drill
hole collar locations for drill holes sampled are outlined in
Figure 2 and detailed in Appendix 1, Table
1.
Table 3: Drill hole sample details
incorporated in composite for HydroFloat testwork
Sample ID |
Drill Hole Number |
From (m) |
To (m) |
Cu Head
Grade(%) |
Au Head
Grade(g/t) |
CHCOM_001 |
KHDDH336 |
50 |
60 |
0.39 |
0.14 |
CHCOM_002 |
KHDDH416 |
150 |
160 |
0.85 |
2.03 |
CHCOM_003 |
KHDDH434 |
62 |
74 |
0.24 |
0.06 |
SHCOM_001 |
KHDDH457 |
64 |
74 |
0.27 |
0.07 |
SHCOM_001 |
KHDDH250 |
220 |
230 |
0.80 |
1.38 |
SHCOM_002 |
KHDDH394 |
112 |
122 |
0.65 |
1.61 |
SHCOM_003 |
KHDDH371 |
269 |
279 |
0.47 |
0.13 |
SHCOM_004 |
KHDDH527 |
66 |
76 |
0.05 |
0.04 |
SHCOM_005 |
KHDDH263 |
288 |
298 |
0.18 |
0.06 |
SHCOM_006 |
KHDDH565 |
195 |
205 |
0.14 |
0.24 |
SHCOM_007 |
KHDDH372 |
140 |
150 |
0.04 |
0.02 |
SHCOM_008 |
KHDDH277 |
204 |
214 |
0.09 |
0.11 |
SHCOM_009 |
KHDDH276 |
70 |
80 |
0.01 |
0.02 |
SHCOM_10 |
KHDDH359 |
200 |
210 |
0.22 |
0.14 |
SHCOM_11 |
KHDDH347 |
502 |
512 |
0.80 |
1.05 |
SHCOM_12 |
KHDDH343 |
180 |
190 |
0.48 |
0.09 |
SHCOM_13 |
KHDDH279 |
336 |
346 |
0.29 |
0.11 |
SHCOM_14 |
KHDDH346 |
364 |
374 |
1.46 |
0.76 |
SHCOM_15 |
KHDDH347 |
170 |
180 |
0.18 |
0.16 |
WHCOM_001 |
KHDDH473 |
63 |
74 |
0.31 |
0.15 |
WHCOM_002 |
KHDDH430 |
458 |
468 |
0.21 |
0.10 |
WHCOM_003 |
KHDDH477 |
263.2 |
274 |
0.33 |
0.44 |
WHCOM_004 |
KHDDH474 |
50 |
60 |
0.16 |
0.05 |
WHCOM_005 |
KHDDH444 |
64 |
74 |
0.36 |
0.14 |
WHCOM_006 |
KHDDH345 |
222 |
232 |
0.28 |
0.17 |
WHCOM_007 |
KHDDH366 |
352 |
362 |
0.17 |
0.08 |
Figure 2: Collar locations for drill
holes sampled in metallurgical testwork
Next Steps
The next step for coarse ore flotation is PFS
process flow sheet modelling and engineering design by DRA, the
engineering firm leading process design and engineering for the
study.
Coarse ore flotation is a subset of the broader
Kharmagtai metallurgical testwork program. The comprehensive
metallurgy program during the Pre-Feasibility Study includes
comminution properties of the mineralisation and alteration styles
at Kharmagtai to determine the optimum flowsheet and generate
inputs for engineering design. This will also generate data to
inform the copper and gold recovery models, and allow operating
costs estimates to be calculated. Concentrate samples will also be
generated for marketing studies as part of the broader metallurgy
program.
About Xanadu Mines
Xanadu is an ASX and TSX listed Exploration
company operating in Mongolia. We give investors exposure to
globally significant, large-scale copper-gold discoveries and
low-cost inventory growth. Xanadu maintains a portfolio of
exploration projects and remains one of the few junior explorers on
the ASX or TSX who jointly control a globally significant
copper-gold deposit in our flagship Kharmagtai project. Xanadu is
the Operator of a 50-50 JV with Zijin Mining Group in Khuiten
Metals Pte Ltd, which controls 76.5% of the Kharmagtai project.
For further information on Xanadu, please visit:
www.xanadumines.com or contact:
Colin MoorheadExecutive
Chairman and Managing DirectorE: colin.moorhead@xanadumines.com P:
+61 2 8280 7497
This Announcement was authorised for release by
Xanadu’s Executive Chair and Managing Director.
Appendix 1: Metallurgical Sample
Composition and Location
Table 1: Drill hole sample details for
rougher flotation testwork
Hole ID |
Sample ID |
Prospect |
East |
North |
RL |
Azimuth(°) |
Inc (°) |
KHDDH336 |
CHCOM_001 |
Copper Hill |
592647 |
4876448 |
1304 |
0 |
-60 |
KHDDH416 |
CHCOM_002 |
Copper Hill |
592698 |
4876440 |
1305 |
246 |
-50 |
KHDDH434 |
CHCOM_003 |
Copper Hill |
592554 |
4876456 |
1302 |
180 |
-62 |
KHDDH457 |
CHCOM_003 |
Copper Hill |
592388 |
4876430 |
1305 |
180 |
-65 |
KHDDH250 |
SHCOM_001 |
Stockwork Hill |
592456 |
4877956 |
1290 |
180 |
-55 |
KHDDH394 |
SHCOM_002 |
Stockwork Hill |
592460 |
4877833 |
1288 |
100 |
-59 |
KHDDH371 |
SHCOM_003 |
Stockwork Hill |
592768 |
4877899 |
1283 |
180 |
-80 |
KHDDH527 |
SHCOM_004 |
Stockwork Hill |
592274 |
4877961 |
1293 |
178 |
-72 |
KHDDH263 |
SHCOM_005 |
Stockwork Hill |
592636 |
4877991 |
1287 |
180 |
-75 |
KHDDH565 |
SHCOM_006 |
Stockwork Hill |
593128 |
4877885 |
1280 |
233 |
-55 |
KHDDH372 |
SHCOM_007 |
Stockwork Hill |
592915 |
4877882 |
1281 |
180 |
-75 |
KHDDH277 |
SHCOM_008 |
Stockwork Hill |
592344 |
4877662 |
1291 |
0 |
-45 |
KHDDH276 |
SHCOM_009 |
Stockwork Hill |
592612 |
4877623 |
1288 |
0 |
-60 |
KHDDH359 |
SHCOM_10 |
Stockwork Hill |
592443 |
4878038 |
1291 |
180 |
-68 |
KHDDH347 |
SHCOM_11 |
Stockwork Hill |
592636 |
4877890 |
1285 |
175 |
-80 |
KHDDH343 |
SHCOM_12 |
Stockwork Hill |
592680 |
4877890 |
1285 |
180 |
-80 |
KHDDH279 |
SHCOM_13 |
Stockwork Hill |
592693 |
4877582 |
1288 |
0 |
-45 |
KHDDH346 |
SHCOM_14 |
Stockwork Hill |
592849 |
4877851 |
1283 |
175 |
-80 |
KHDDH347 |
SHCOM_15 |
Stockwork Hill |
592636 |
4877890 |
1285 |
175 |
-80 |
KHDDH473 |
WHCOM_001 |
White Hill |
591894 |
4877307 |
1305 |
0 |
-60 |
KHDDH430 |
WHCOM_002 |
White Hill |
592097 |
4877422 |
1301 |
200 |
-60 |
KHDDH477 |
WHCOM_003 |
White Hill |
592100 |
4877097 |
1305 |
0 |
-60 |
KHDDH474 |
WHCOM_004 |
White Hill |
591900 |
4877496 |
1299 |
0 |
-60 |
KHDDH444 |
WHCOM_005 |
White Hill |
592159 |
4877565 |
1296 |
205 |
-60 |
KHDDH345 |
WHCOM_006 |
White Hill |
592065 |
4877380 |
1305 |
176 |
-73 |
KHDDH366 |
WHCOM_007 |
White Hill |
591943 |
4877319 |
1309 |
5 |
-82 |
KHDDH226 |
WHCOM_008 |
White Hill |
592041 |
4877274 |
1310 |
90 |
-50 |
KHDDH322 |
WHCOM_009 |
White Hill |
592248 |
4876940 |
1302 |
0 |
-60 |
KHDDH308 |
WHCOM_010 |
White Hill |
591674 |
4877243 |
1305 |
90 |
-53 |
Appendix 2: Statements and
Disclaimers
Competent Person Statements
The information in this announcement that
relates to exploration results is based on information compiled by
Dr Andrew Stewart, who is responsible for the exploration data,
comments on exploration target sizes, QA/QC and geological
interpretation and information. Dr Stewart, who is an employee of
Xanadu and is a Member of the Australasian Institute of
Geoscientists, has sufficient experience relevant to the style of
mineralisation and type of deposit under consideration and to the
activity he is undertaking to qualify as the Competent Person as
defined in the 2012 Edition of the Australasian Code for Reporting
Exploration Results, Mineral Resources and Ore Reserves and the
National Instrument 43-101. Dr Stewart consents to the inclusion in
the report of the matters based on this information in the form and
context in which it appears.
The information in this Announcement that
relates to metallurgy and metallurgical testwork has been reviewed
by Graham Brock, BSc (Eng), ARSM. Mr Brock is not an employee of
the Company but is employed as a contract consultant. Mr Brock is a
Fellow of the Australasian Institute of Mining and Metallurgy; he
has sufficient experience with the style of processing response and
type of deposit under consideration, and to the activities
undertaken, to qualify as a competent as defined in the 2012
Edition of the Australasian Code for Reporting Exploration Results,
Mineral Resources and Ore Reserves and the National Instrument
43-101. Mr Brock consents to the inclusion in this report of the
contained technical information in the form and context as it
appears.
Forward-Looking Statements
Certain statements contained in this
Announcement, including information as to the future financial or
operating performance of Xanadu and its projects may also include
statements which are ‘forward‐looking statements’ that may include,
amongst other things, statements regarding targets, estimates and
assumptions in respect of mineral reserves and mineral resources
and anticipated grades and recovery rates, production and prices,
recovery costs and results, capital expenditures and are or may be
based on assumptions and estimates related to future technical,
economic, market, political, social and other conditions. These
‘forward-looking statements’ are necessarily based upon a number of
estimates and assumptions that, while considered reasonable by
Xanadu, are inherently subject to significant technical, business,
economic, competitive, political and social uncertainties and
contingencies and involve known and unknown risks and uncertainties
that could cause actual events or results to differ materially from
estimated or anticipated events or results reflected in such
forward‐looking statements.
Xanadu disclaims any intent or obligation to
update publicly or release any revisions to any forward‐looking
statements, whether as a result of new information, future events,
circumstances or results or otherwise after the date of this
Announcement or to reflect the occurrence of unanticipated events,
other than required by the Corporations Act 2001 (Cth) and the
Listing Rules of the Australian Securities Exchange
(ASX) and Toronto Stock Exchange
(TSX). The words ‘believe’, ‘expect’,
‘anticipate’, ‘indicate’, ‘contemplate’, ‘target’, ‘plan’,
‘intends’, ‘continue’, ‘budget’, ‘estimate’, ‘may’, ‘will’,
‘schedule’ and similar expressions identify forward‐looking
statements.
All ‘forward‐looking statements’ made in this
Announcement are qualified by the foregoing cautionary statements.
Investors are cautioned that ‘forward‐looking statements’ are not
guarantee of future performance and accordingly investors are
cautioned not to put undue reliance on ‘forward‐looking statements’
due to the inherent uncertainty therein.
For further information please visit the Xanadu
Mines’ Website at www.xanadumines.com.
Appendix 3: Kharmagtai Table 1 (JORC
2012)
Set out below is Section 1 and Section 2 of
Table 1 under the JORC Code, 2012 Edition for the Kharmagtai
project. Data provided by Xanadu. This Table 1 updates the JORC
Table 1 disclosure dated 8 December 2023.
JORC TABLE 1 - SECTION 1 - SAMPLING
TECHNIQUES AND DATA
(Criteria in this section apply to all succeeding sections).
Criteria |
Commentary |
Sampling techniques |
- Representative ½
core samples were split from PQ, HQ and NQ diameter diamond drill
core on site using rock saws, on a routine 2m sample interval that
also honours lithological/intrusive contacts.
- The orientation
of the cut line is controlled using the core orientation line
ensuring uniformity of core splitting wherever the core has been
successfully oriented.
- Sample intervals
are defined and subsequently checked by geologists, and sample tags
are attached (stapled) to the plastic core trays for every sample
interval.
- Reverse
Circulation (RC) chip samples are ¼ splits from
one-meter (1m) intervals using a 75%:25% riffle
splitter to obtain a 3kg sample
- RC samples are
uniform 2m samples formed from the combination of two ¼ split 1m
samples.
|
Drilling techniques |
- The Mineral
Resource Estimation has been based upon diamond drilling of PQ, HQ
and NQ diameters with both standard and triple tube core recovery
configurations, RC drilling and surface trenching with channel
sampling.
- All drill core
drilled by Xanadu has been oriented using the “Reflex Ace”
tool.
|
Drill sample recovery |
- Diamond drill
core recoveries were assessed using the standard industry (best)
practice which involves removing the core from core trays;
reassembling multiple core runs in a v-rail; measuring core lengths
with a tape measure, assessing recovery against core block depth
measurements and recording any measured core loss for each core
run.
- Diamond core
recoveries average 97% through mineralisation.
- Overall, core
quality is good, with minimal core loss. Where there is localised
faulting and or fracturing core recoveries decrease, however, this
is a very small percentage of the mineralised intersections.
- RC recoveries
are measured using whole weight of each 1m intercept measured
before splitting
- Analysis of
recovery results vs grade shows no significant trends that might
indicate sampling bias introduced by variable recovery in
fault/fracture zones.
|
Logging |
- All drill core
is geologically logged by well-trained geologists using a modified
“Anaconda-style” logging system methodology. The Anaconda method of
logging and mapping is specifically designed for porphyry Cu-Au
mineral systems and is entirely appropriate to support Mineral
Resource Estimation, mining and metallurgical studies.
- Logging of
lithology, alteration and mineralogy is intrinsically qualitative
in nature. However, the logging is subsequently supported by 4 Acid
ICP-MS (48 element) geochemistry and SWIR spectral mineralogy
(facilitating semi-quantitative/calculated mineralogical,
lithological and alteration classification) which is integrated
with the logging to improve cross section interpretation and 3D
geological model development.
- Drill core is
also systematically logged for both geotechnical features and
geological structures. Where drill core has been successfully
oriented, the orientation of structures and geotechnical features
are also routinely measured.
- Both wet and dry
core photos are taken after core has been logged and marked-up but
before the drill core has been cut.
|
Sub-sampling techniques and sample
preparation |
- All drill core
samples are ½ core splits from either PQ, HQ or NQ diameter cores.
A routine 2m sample interval is used, but this is varied locally to
honour lithological/intrusive contacts. The minimum allowed sample
length is 30cm.
- Core is
appropriately split (onsite) using diamond core saws with the cut
line routinely located relative to the core orientation line (where
present) to provide consistency of sample split selection.
- The diamond saws
are regularly flushed with water to minimize potential
contamination.
- A field
duplicate ¼ core sample is collected every 30th sample to ensure
the “representivity of the in-situ material collected”. The
performance of these field duplicates is routinely analysed as part
of Xanadu’s sample QC process.
- Routine sample
preparation and analyses of DDH samples were carried out by ALS
Mongolia LLC (ALS Mongolia), who operates an
independent sample preparation and analytical laboratory in
Ulaanbaatar.
- All samples were
prepared to meet standard quality control procedures as follows:
Crushed to 75% passing 2mm, split to 1kg, pulverised to 85% passing
200 mesh (75 microns) and split to 150g sample pulp.
- ALS Mongolia
Geochemistry labs quality management system is certified to ISO
9001:2008.
- The sample
support (sub-sample mass and comminution) is appropriate for the
grainsize and Cu-Au distribution of the porphyry Cu-Au
mineralization and associated host rocks.
- Sample
preparation at ALS Perth Labs consisted of homogenising and
splitting samples “as received” into a single 150kg composite. The
composite was crushed to 3.35mm, followed by rotary blending and
splitting, and then 1kg grind samples were separated for head
assay, size fractions and testwork.
|
Quality of assay data and laboratory tests |
- All samples were
routinely assayed by ALS Mongolia for gold.
- Au is determined
using a 25g fire assay fusion, cupelled to obtain a bead, and
digested with Aqua Regia, followed by an atomic absorption
spectroscopy (AAS) finish, with a lower detection
(LDL) of 0.01 ppm.
- All samples were
also submitted to ALS Mongolia for the 48-element package ME-ICP61
using a four-acid digest (considered to be an effective total
digest for the elements relevant to the Mineral Resource Estimate
(MRE)). Where copper is over-range (>1% Cu), it
is analysed by a second analytical technique (Cu-OG62), which has a
higher upper detection limit (UDL) of 5%
copper.
- Quality
assurance has been managed by insertion of appropriate Standards
(1:30 samples – suitable Ore Research Pty Ltd certified standards),
Blanks (1:30 samples), Duplicates (1:30 samples – ¼ core duplicate)
by XAM.
- Assay results
outside the optimal range for methods were re-analysed by
appropriate methods.
- Ore Research Pty
Ltd certified copper and gold standards have been implemented as a
part of QC procedures, as well as coarse and pulp blanks, and
certified matrix matched copper-gold standards.
- QC monitoring is
an active and ongoing processes on batch-by-batch basis by which
unacceptable results are re-assayed as soon as practicable.
- Prior to 2014:
Cu, Ag, Pb, Zn, As and Mo were routinely determined using a
three-acid-digestion of a 0.3g sub-sample followed by an AAS finish
(AAS21R) at SGS Mongolia. Samples were digested with nitric,
hydrochloric and perchloric acids to dryness before leaching with
hydrochloric acid to dissolve soluble salts and made to 15ml volume
with distilled water. The LDL for copper using this technique was
2ppm. Where copper was over-range (>1% Cu), it was analysed by a
second analytical technique (AAS22S), which has a higher upper
detection limit (UDL) of 5% copper. Gold analysis method was
essentially unchanged.
- Assays were
carried out at ALS’ laboratory in, Perth. Gold and copper solid
assays were determined using Fire Assay followed by AAS. Solution
assays were determined using AAS.
|
Verification of sampling and assaying |
- All assay data
QA/QC is checked prior to loading into XAM’s Geobank data
base.
- The data is
managed by XAM geologists.
- The data base
and geological interpretation is managed by XAM.
- Check assays are
submitted to an umpire lab (SGS Mongolia) for duplicate
analysis.
- No twinned drill
holes exist.
- There have been
no adjustments to any of the assay data.
|
Location of data points |
- Diamond drill
holes have been surveyed with a differential global positioning
system (DGPS) to within 10cm accuracy.
- The grid system
used for the project is UTM WGS-84 Zone 48N
- Historically,
Eastman Kodak and Flexit electronic multi-shot downhole survey
tools have been used at Kharmagtai to collect down hole azimuth and
inclination information for the majority of the diamond drill
holes. Single shots were typically taken every 30m to 50m during
the drilling process, and a multi-shot survey with readings every
3-5m are conducted at the completion of the drill hole. As these
tools rely on the earth’s magnetic field to measure azimuth, there
is some localised interference/inaccuracy introduced by the
presence of magnetite in some parts of the Kharmagtai mineral
system. The extent of this interference cannot be quantified on a
reading-by-reading basis.
- More recently
(since September 2017), a north-seeking gyro has been employed by
the drilling crews on site (rented and operated by the drilling
contractor), providing accurate downhole orientation measurements
unaffected by magnetic effects. Xanadu have a permanent calibration
station setup for the gyro tool, which is routinely calibrated
every 2 weeks (calibration records are maintained and were
sighted)
- The project
Digital Terrain Model (DTM) is based on 1m
contours from satellite imagery with an accuracy of ±0.1 m.
|
Data spacing and distribution |
- Holes spacings
range from <50m spacings within the core of mineralization to
+500m spacings for exploration drilling. Hole spacings can be
determined using the sections and drill plans provided.
- Holes range from
vertical to an inclination of -60 degrees depending on the attitude
of the target and the drilling method.
- The data spacing
and distribution is sufficient to establish anomalism and targeting
for porphyry Cu-Au, tourmaline breccia and epithermal target
types.
- Holes have been
drilled to a maximum of 1,304m vertical depth.
- The data spacing
and distribution is sufficient to establish geological and grade
continuity, and to support the Mineral Resource
classification.
|
Orientation of data in relation to geological
structure |
- Drilling is
conducted in a predominantly regular grid to allow unbiased
interpretation and targeting.
- Scissor
drilling, as well as some vertical and oblique drilling, has been
used in key mineralised zones to achieve unbiased sampling of
interpreted structures and mineralised zones, and to assist in
constraining the geometry of the mineralised hydrothermal
tourmaline-sulphide breccia domains.
|
Sample security |
- Samples are
delivered from the drill rig to the core shed twice daily and are
never left unattended at the rig.
- Samples are
dispatched from site in locked boxes transported on XAM company
vehicles to ALS lab in Ulaanbaatar.
- Sample shipments
from Ulaanbaatar to ALS’ laboratory in Perth are dispatched in
locked barrels and transported via air freight.
- Sample shipment
receipt is signed off at the Laboratory with additional email
confirmation of receipt.
- Samples are then
stored at the lab and returned to a locked storage site.
|
Audits or reviews |
- Internal audits
of sampling techniques and data management are undertaken on a
regular basis, to ensure industry best practice is employed at all
times.
- External reviews
and audits have been conducted by the following groups:
- 2012: AMC
Consultants Pty Ltd was engaged to conduct an Independent Technical
Report which reviewed drilling and sampling procedures. It was
concluded that sampling and data record was to an appropriate
standard.
- 2013: Mining
Associates Ltd was engaged to conduct an Independent Technical
Report to review drilling, sampling techniques and QAQC. Methods
were found to conform to international best practice.
- 2018: CSA Global
reviewed the entire drilling, logging, sampling, sample shipping
and laboratory processes during the competent persons site visit
for the 2018 MRE and found the systems and adherence to protocols
to be to an appropriate standard.
|
JORC TABLE 1 - SECTION 2 - REPORTING OF
EXPLORATION RESULTS
(Criteria in this section apply to all succeeding sections).
Criteria |
Commentary |
Mineraltenementand
landtenurestatus |
- The Project comprises two Mining
Licences (MV-17129A Oyut Ulaan and (MV-17387A Kharmagtai):
- Xanadu now owns 90% of Vantage LLC,
the 100% owner of the Oyut Ulaan mining licence.
- The Kharmagtai mining license
MV-17387A is 100% owned by Oyut Ulaan LLC. Xanadu has an 85%
interest in Mongol Metals LLC, which has a 90% interest in Oyut
Ulaan LLC. The remaining 10% in Oyut Ulaan LLC is owned by Quincunx
(BVI) Ltd.
- The Mongolian Minerals Law (2006)
and Mongolian Land Law (2002) govern exploration, mining and land
use rights for the project.
|
Explorationdone
byotherparties |
- Previous exploration at Kharmagtai
was conducted by Quincunx Ltd, Ivanhoe Mines Ltd and Turquoise Hill
Resources Ltd including extensive drilling, surface geochemistry,
geophysics, mapping.
- Previous exploration at Red
Mountain (Oyut Ulaan) was conducted by Ivanhoe Mines.
|
Geology |
- The mineralisation is characterised
as porphyry copper-gold type.
- Porphyry copper-gold deposits are
formed from magmatic hydrothermal fluids typically associated with
felsic intrusive stocks that have deposited metals as sulphides
both within the intrusive and the intruded host rocks. Quartz
stockwork veining is typically associated with sulphides occurring
both within the quartz veinlets and disseminated thought out the
wall rock. Porphyry deposits are typically large tonnage deposits
ranging from low to high grade and are generally mined by large
scale open pit or underground bulk mining methods. The deposits at
Kharmagtai are atypical in that they are associated with
intermediate intrusions of diorite to quartz diorite composition;
however, the deposits are in terms of contained gold significant,
and similar gold-rich porphyry deposits.
|
Drill holeInformation |
- Diamond drill holes are the
principal source of geological and grade data for the Project.
- See figures in this ASX/TSX
Announcement.
|
DataAggregation methods |
- The CSAMT data was converted into
2D line data using the Zonge CSAMT processing software and then
converted into 3D space using a UBC inversion process. Inversion
fit was acceptable, and error was generally low.
- A nominal cut-off of 0.1% CuEq is
used in copper dominant systems for identification of potentially
significant intercepts for reporting purposes. Higher grade
cut-offs are 0.3%, 0.6% and 1% CuEq.
- A nominal cut-off of 0.1g/t AuEq is
used in gold dominant systems like Golden Eagle for identification
of potentially significant intercepts for reporting purposes.
Higher grade cut-offs are 0.3g/t, 0.6g/t and 1g/t AuEq.
- Maximum contiguous dilution within
each intercept is 9m for 0.1%, 0.3%, 0.6% and 1% CuEq.
- Most of the reported intercepts are
shown in sufficient detail, including maxima and subintervals, to
allow the reader to make an assessment of the balance of high and
low grades in the intercept.
- Informing samples have been
composited to two metre lengths honouring the geological domains
and adjusted where necessary to ensure that no residual sample
lengths have been excluded (best fit).
The copper equivalent (CuEq) calculation
represents the total metal value for each metal, multiplied by the
conversion factor, summed and expressed in equivalent copper
percentage with a metallurgical recovery factor applied. The copper
equivalent calculation used is based off the CuEq calculation
defined by CSA Global in the 2018 Mineral Resource Upgrade.Copper
equivalent (CuEq) grade values were calculated
using the following formula:
CuEq = Cu + Au * 0.62097 * 0.8235,Gold Equivalent
(AuEq) grade values were calculated using the
following formula:
AuEq = Au +
Cu / 0.62097 * 0.8235.Where:Cu - copper grade (%)Au - gold grade
(g/t)0.62097 - conversion factor (gold to copper)0.8235 - relative
recovery of gold to copper (82.35%)The copper equivalent formula
was based on the following parameters (prices are in USD):
- Copper price - $3.10/lb (or
$6,834/t)
- Gold price $1,320/oz
- Copper recovery - 85%
- Gold recovery - 70%
- Relative recovery of gold to copper
= 70% / 85% = 82.35%.
|
Relationship between
mineralisation on
widths and
intercept lengths |
- Mineralised structures are variable
in orientation, and therefore drill orientations have been adjusted
from place to place in order to allow intersection angles as close
as possible to true widths.
- Exploration results have been
reported as an interval with 'from' and 'to' stated in tables of
significant economic intercepts. Tables clearly indicate that true
widths will generally be narrower than those reported.
|
Diagrams |
- See figures in the body of this
ASX/TSX Announcement.
|
Balanced reporting |
- Resources have been reported at a
range of cut-off grades, above a minimum suitable for open pit
mining, and above a minimum suitable for underground mining.
|
Other substantiveExploration
data |
- Extensive work in this area has
been done and is reported separately.
|
FurtherWork |
- The mineralisation is open at depth
and along strike.
- Current estimates are restricted to
those expected to be reasonable for open pit mining. Limited
drilling below this depth (-300m RL) shows widths and grades
potentially suitable for underground extraction.
- Exploration ongoing.
|
JORC TABLE 1 - SECTION 3 - ESTIMATION
AND REPORTING OF MINERAL RESOURCES
Mineral Resources are not reported so this is
not applicable to this Announcement. Please refer to the Company’s
ASX Announcement dated 8 December 2023 for Xanadu’s most recent
reported Mineral Resource Estimate and applicable Table 1, Section
3.
JORC TABLE 1 - SECTION 4 - ESTIMATION
AND REPORTING OF ORE RESERVES
Ore Reserves are not reported so this is not
applicable to this Announcement.
________________
1 ASX/TSX Announcement 8 April 2022 – Scoping Study Kharmagtai
Copper-Gold Project2 ASX/TSX Announcement 4 March 2024 –
Metallurgical Tests at Kharmagtai Show Strong Sulphide Rougher
Flotation Recovery
Photos accompanying this announcement are available
at:https://www.globenewswire.com/NewsRoom/AttachmentNg/cb00cc1d-566d-4f90-95a6-20093f14e37c
https://www.globenewswire.com/NewsRoom/AttachmentNg/ca3f93b2-7a36-45bb-9517-50abdc853379
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