REG - Castillo Copper Ltd - Test-work confirms 5-10x upgrade for Cu at Big One
19/07/2022 07:00
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RNS Number : 8903S Castillo Copper Limited 19 July 2022
19 July 2022
CASTILLO COPPER LIMITED
("Castillo" or the "Company")
Metallurgical test-work confirms ~10x upgrade for copper at Big One Deposit
Castillo Copper Limited (LSE and ASX: CCZ), a base metal explorer primarily
focused on copper across Australia and Zambia, is pleased to announce that
preliminary metallurgical test-work on samples from drill-hole BO_318RC at the
Big One Deposit(1) (NWQ Copper Project, Mt Isa copper-belt) delivered
encouraging initial results.
HIGHLIGHTS
· Preliminary metallurgical test-work on samples extracted from
drill-hole BO_318RC(1) at the Big One Deposit produced a concentrate with
confirmed upgrades ranging from 5x to 10x for copper metal (Appendix A &
B), with the best result:
o Copper: 0.72% head-grade to 7.2% post-test-work
· Further test-work is underway on samples from the Big One Deposit to
determine the final optimal results, since this is an important proof of
concept and de-risking exercise as part of the Board's strategic intent to
secure a processing agreement
· The Big One Deposit has already been significantly de-risked as the
current global inferred Mineral Resource Estimate ("MRE") stands at 21,886t
contained copper metal (2.1Mt @ 1.1% Cu(2)):
o Current forward plans include undertaking a third drilling campaign to
extend known mineralisation via focusing on a sizeable known bedrock conductor
north of the line of lode and incremental geophysical surveys to identify
fresh targets(2)
· Metallurgical test-work is being undertaken for cobalt on drill-core
samples from The Sisters Prospect in Broken Hill - results are due shortly
Dr Dennis Jensen, Managing Director of Castillo Copper, commented: "The Board
is delighted with the preliminary metallurgical test-work results, especially
with the beneficiation potentially transforming the ore from the Big One
Deposit into a viable copper concentrate. Moreover, receiving these initial
results now is timely as the Board is now ramping up efforts to secure a
processing agreement and clear path to market."
FIGURE 1: METALLURGICAL TEST-WORK COPPER HEAD GRADE IMPROVEMENT
Assay Head Weight% Cu % Improve % Distribution %
Ro Con 1 1.76 6.86 958.1 14.03
Ro Con 1-2 5.50 7.24 1011.3 46.29
Ro Con 1-3 11.66 5.31 741.2 71.91
Ro Con 1-4 22.69 3.38 472.5 89.22
Note: Using Danafloat. Source: ALS Metallurgy, Perth, Western Australia
FIGURE 2: METALLURGICAL TESTING - FROTHER PRODUCT EXAMPLE
Source: ALS Metallurgy, Perth, Western Australia
De-risking Big One Deposit
Although the preliminary metallurgical results deliver an encouraging start,
further test-work is underway to optimise the outcome. This is critical to
move beyond the proof-of-concept stage and boost the prospect of securing a
processing agreement with a blue-chip partner in the Mt Isa copper-belt.
To date, the Big One Deposit has already been significantly de-risked given
the current global inferred MRE is 21,886t contained copper metal (2.1Mt @
1.1% Cu(2)).
The Board has been revising plans for the Big One Deposit and plans to do the
following:
· Conducting a third drilling campaign to extend known mineralisation
through focusing on the sizeable known bedrock conductor that is north of the
line of lode; and
· Undertaking additional geophysical surveys to identify new targets
for test-drilling.
Methodology
Castillo contracted ALS Metallurgy, Perth, Western Australia, to undertake
test-work on a circa 33kg composite derived from drill-hole BO_318RC from the
Big One Deposit(1) (Figure 3). The material was fresh and taken wholly from
within the mineralised dacite/porphyritic syenite dyke intersected by most of
the drilling at the Big One Deposit.
FIGURE 3: BIG ONE DEPOSIT SAMPLE FOR METALLURGICAL TESTING
Borehole Sample # From (m) To (m) Thick-ness (m) ORIGINAL Weight (kg) COARSE REJECT Weight (kg) Au Ag Cr Co Cu Rb Rock type
BO_318RC CCZ01169 167 168 1.00 2.71 2.21 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01170 168 169 1.00 2.86 2.36 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01171 169 170 1.00 3.01 2.51 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01172 170 171 1.00 3.29 2.79 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01173 171 172 1.00 2.23 1.73 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01174 172 173 1.00 2.50 2.00 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01175 173 174 1.00 2.93 2.43 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01176 174 175 1.00 3.26 2.76 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01177 175 176 1.00 3.01 2.51 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01178 176 177 1.00 3.90 3.40 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01179 177 178 1.00 2.12 1.62 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01180 178 179 1.00 2.70 2.20 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01181 179 180 1.00 2.73 2.23 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01182 180 181 1.00 3.00 2.50 0.03 0.59 332 184 6553 157 Dacite
14 40.25 33.25
Source: ALS Metallurgy, Perth, Western Australia
Further work at the laboratory determined the head grade of the composite
sample was slightly better (Figure 4) than the calculated arithmetic average
shown selectively in Figure 3.
FIGURE 4: 14M BO_318RC BIG ONE DEPOSIT - TESTING HEAD GRADE
Analyte Grade Analyte Grade
Ag (ppm) 0.9 Mg (%) 1.84
Al (%) 8.20 Mn (ppm) 1,600
Au (g/t) <0.02 Mo (ppm) <5
Ba (ppm) 200 Na (ppm) 760
Be (ppm) 5 Ni (ppm) 105
Bi (ppm) 20 P (ppm) 600
Ca (%) 2.80 Pb (ppm) 20
Cd (ppm) <5 SiO2 (%) 38.0
Co (ppm) 275 Sr (ppm) 18
Cr (ppm) 260 Ti (ppm) 5,400
Cu (ppm) 7,160 V (ppm) 258
Fe (%) 3.94 Y (ppm) <10
K (%) 6.40 Zn (ppm) 32
Li (ppm) 15
Source: ALS Metallurgy, Perth, Western Australia
The testing process comprised a series of rougher tests with the following
sequences:
A) Sample preparation and screening analysis
· Receive samples and inventory
· Control crush P100 3.35mm (assumed no compositing)
· Rotary blending & splitting 1kg charges (12 x 1kg)
· PPS - Head assay submission
· Assay - Head sample (Ag, Au, Co, Cu, SiO(2), ICP Scan)
B) Flotation and gravity testing
· 1 kg grind establishment single grind target
· Rougher flotation (4 con 1 tail) (5 test allowance)
· PPS - Flotation product assay submission
· Assay - Flotation products (Ag, Au, Co, Cu, Zn, SiO2)
· Gravity separation - Wilfley table - Batch test
· PPS - Table product assay submission
· Assay - Table products (Ag, Au, Co, Cu, Zn, SiO(2))
Two runs were established comparing two common froth reagents (Aerofloat and
Danafloat - refer Appendix B). The batch froth flotation results were
partially affected by remanent drilling foam imbedded in the reverse
circulation chips (refer Figure 2 above).
However, when comparing the frother product concentrates, Danafloat produced
the best concentration of copper relative to Aerofloat (refer Figure 1 and 5).
FIGURE 5: COMPARING AEROFLOAT & DANAFLOAT CONCENTRATES
Source: ALS Metallurgy, Perth, Western Australia
Note, at this stage of the process, preliminary rougher testing is potentially
biased towards establishing a viable process configuration and recovery rather
than grade. However, when assessing other metals (Ag, Au & Co) using the
Danafloat for various concentrate runs, there were a range of material
improvements (refer Figure 6).
FIGURE 6: DANAFLOAT HEAD GRADE IMPROVEMENT FOR SILVER-GOLD-COBALT
Assay Head Weight% Ag (g/t) Improve % Distribution Au g/t Improve % Distribution Co ppm Improve % Distribution %
% %
Ro Con 1 1.76 5.00 555.6 13.65 0.05 500.0 1.66 760 276.4 5.17
Ro Con 1-2 5.50 6.36 706.7 54.25 0.05 500.0 5.18 848 308.4 18.04
Ro Con 1-3 11.66 4.59 509.5 82.89 0.08 764.1 16.78 770 280.0 34.70
Ro Con 1-4 22.69 2.84 315.8 100.00 0.06 635.7 27.18 697 253.5 61.15
To build on this preliminary work a larger sample - circa 50Kg ideally from
diamond core - would enable further beneficiation streams and trialling finer
crushed material.
In addition to this release, a PDF version with supplementary information and
images can be found on the Company's website:
https://castillocopper.com/investors/announcements/
(https://castillocopper.com/investors/announcements/)
For further information, please contact:
Castillo Copper Limited +61 8 6558 0886
Dr Dennis Jensen (Australia), Managing Director
Gerrard Hall (UK), Chairman
SI Capital Limited (Financial Adviser and Corporate Broker) +44 (0)1483 413500
Nick Emerson
Luther Pendragon (Financial PR) +44 (0)20 7618 9100
Harry Chathli, Alexis Gore
About Castillo Copper
Castillo Copper Limited is an Australian-based explorer primarily focused on
copper across Australia and Zambia. The group is embarking on a strategic
transformation to morph into a mid-tier copper group underpinned by its core
projects:
· A large footprint in the Mt Isa copper-belt district, north-west
Queensland, which delivers significant exploration upside through having
several high-grade targets and a sizeable untested anomaly within its
boundaries in a copper-rich region.
· Four high-quality prospective assets across Zambia's copper-belt
which is the second largest copper producer in Africa.
· A large tenure footprint proximal to Broken Hill's world-class
deposit that is prospective for zinc-silver-lead-copper-gold and platinoids.
· Cangai Copper Mine in northern New South Wales, which is one of
Australia's highest grading historic copper mines.
The group is listed on the LSE and ASX under the ticker "CCZ."
Competent Person's Statement
The information in this report that relates to Exploration Results and Mineral
Resource Estimates for "BHA Project, East Zone" is based on information
compiled or reviewed by Mr Mark Biggs. Mr Biggs is a director of ROM
Resources, a company which is a shareholder of Castillo Copper Limited. ROM
Resources provides ad hoc geological consultancy services to Castillo Copper
Limited. Mr Biggs is a member of the Australian Institute of Mining and
Metallurgy (member #107188) and has sufficient experience of relevance to the
styles of mineralisation and types of deposits under consideration, and to the
activities undertaken, to qualify as a Competent Person as defined in the 2012
Edition of the Joint Ore Reserves Committee (JORC) Australasian Code for
Reporting of Exploration Results, and Mineral Resources. Mr Biggs holds an
AusIMM Online Course Certificate in 2012 JORC Code Reporting. Mr Biggs also
consents to the inclusion in this report of the matters based on information
in the form and context in which it appears.
References
1) CCZ ASX Release- 30 November 2021
2) CCZ ASX Release - 28 February 2022
APPENDIX A: FULL METALLURGICAL TESTWORK RESULTS
Source: ALS Metallurgy, Perth, Western Australia
Source: ALS Metallurgy, Perth, Western Australia
APPENDIX B: JORC CODE, 2012 EDITION - TABLE 1
The following JORC Code (2012 Edition) Table 1 is primarily supplied for the
provision of metallurgy results at the Big One Deposit. There is additional
commentary provided at the end of Section 2.
Section 1 Sampling Techniques and Data
Criteria JORC Code explanation Commentary
Sampling techniques · Nature and quality of sampling (eg cut channels, random chips, or · For the 2022 Met Testing program, BO_318RC reverse circulation
specific specialised industry standard measurement tools appropriate to the samples were taken off a cyclone for every metre drilled, put through a three
minerals under investigation, such as down hole gamma sondes, or handheld XRF tier, 87.5/12.5 splitter where approximately 2.5 kg of RC chip samples were
instruments, etc.). These examples should not be taken as limiting the broad collected for every metre drilled. The remainder was bagged separately and
meaning of sampling. stored in case additional sub sampling is required before the end of the
program.
· Include reference to measures taken to ensure sample
representivity and the appropriate calibration of any measurement tools or · Weights recovered for each 1m sample from riffle splitting varied
systems used. between 1-2kg for both the 1970 and 1993 drilling programs.
· Aspects of the determination of mineralisation that are Material · For the 2021 program, samples were also composited every four
to the Public Report. metres where visual inspection did not initially indicate copper
mineralisation. All samples were collected to maximise optimal
· In cases where 'industry standard' work has been done this would representation for each sample.
be relatively simple (e.g., 'reverse circulation drilling was used to obtain 1
m samples from which 3 kg was pulverised to produce a 30 g charge for fire · Each metre sample had an amount removed for washing and cleaning
assay'). In other cases, more explanation may be required, such as where there and sieving then place into metre allocated chip trays. These chips were
is coarse gold that has inherent sampling problems. Unusual commodities or logged on site by the rig geologists and those logs have been saved into a
mineralisation types (e.g., submarine nodules) may warrant disclosure of spreadsheet and stored on the Company server. Any visible mineralisation,
detailed information. alteration or other salient features were recorded in the logs.
Industry-wide, acceptable, standard practices were adhered to for the drilling
and sampling of each metre as per the drilling and sampling Procedures set out
before commencement of the drilling programme.
Drilling techniques · Drill type (e.g., core, reverse circulation, open-hole hammer, · Reverse Circulation, RC, and HQ-sized diamond wireline drilling
rotary air blast, auger, Bangka, sonic, etc) and details (e.g., core diameter, techniques were utilised for all holes drilled at the Big One Deposit.
triple or standard tube, depth of diamond tails, face-sampling bit, or other
type, whether core is oriented and if so, by what method, etc).
Drill sample recovery · Method of recording and assessing core and chip sample recoveries · For the 2021 program, within acceptable industry standard limits,
and results assessed. all samples collected were of near equal mass and recoveries were also within
acceptable limits for RC drilling and all recorded in the daily logs. Every
· Measures taken to maximise sample recovery and ensure effort was made on site to maximise recovery including cleaning out the sample
representative nature of the samples. trays, splitter and cyclone and ensuring that the drillers progressed at a
steady constant rate for the rig to easily complete each metre effectively.
· Whether a relationship exists between sample recovery and grade
and whether sample bias may have occurred due to preferential loss/gain of
fine/coarse material.
Logging · Whether core and chip samples have been geologically and · For all drilling programs, every metre drilled and sampled was
geotechnically logged to a level of detail to support appropriate Mineral logged geologically in accordance with industry-wide acceptable standard for
Resource estimation, mining studies and metallurgical studies. RC logging and the logging was qualitative in nature with every metre logged.
Unfortunately, lithology dictionaries and descriptions varied between
· Whether logging is qualitative or quantitative in nature. Core programs. The 2021 programs also recorded visible sulphide and carbonate
(or costean, channel, etc) photography. concentrations and alteration minerals, such as orthoclase, epidote, chlorite,
and sericite.
· The total length and percentage of the relevant intersections
logged.
Sub-sampling techniques and sample preparation · If core, whether cut or sawn and whether quarter, half or all · For the 2021 program, samples with pXRF copper >200ppm were
core taken. composited every four metres and all samples were collected to maximise
optimal representation for each sample. If XRF is not available, then all
· If non-core, whether riffled, tube sampled, rotary split, etc and samples with no visible mineralisation will be sampled as above.
whether sampled wet or dry.
· Each metre sample had an amount removed for washing and cleaning
· For all sample types, the nature, quality, and appropriateness of and sieving then place into metre allocated chip trays. These chips were
the sample preparation technique. logged on site by the rig geologists and those logs have been saved into a
spreadsheet and stored on the Company server. Any visible mineralisation,
· Quality control procedures adopted for all sub-sampling stages to alteration or other salient features were recorded in the logs. Industry wide,
maximise representivity of samples. acceptable, standard practices were adhered to for the drilling and sampling
of each metre as per the Drilling and Sampling Procedures set out before
· Measures taken to ensure that the sampling is representative of commencement of the drilling programme.
the in-situ material collected, including for instance results for field
duplicate/second-half sampling. · For BO_318RC the mineralised intervals were composited on a
received apparent thickness x interval calculation (i.e., thickness averaged).
· Whether sample sizes are appropriate to the grain size of the See Table B1-1.
material being sampled.
Quality of assay data and laboratory tests · The nature, quality and appropriateness of the assaying and · Castillo's's DDH and RC holes have been assayed by an independent
laboratory procedures used and whether the technique is considered partial or laboratory, ALS at Mt Isa, Townsville, or Brisbane Australia. Methods used
total. were as follows:
· For geophysical tools, spectrometers, handheld XRF instruments, o Gold - by method Au-AA25 30g charge (fire Assay with AAS finish).
etc, the parameters used in determining the analysis including instrument make
and model, reading times, calibrations factors applied and their derivation, o High gold values within oxide zone/supergene zone may need further testing
etc. by method Au-SCR21.
· Nature of quality control procedures adopted (eg standards, o Copper and 32 other - by method ME-ICP41 (HF-HN03-HCL04 acid digest, HCL
blanks, duplicates, external laboratory checks) and whether acceptable levels leach and ICP-AES finish).
of accuracy (i.e. lack of bias) and precision have been established.
o Over-limit copper (>10,000 ppm 0.01% ) to be re assayed for copper by
method Cu-OC62 (HF-HN03-HCL04 acid digest, HCL leach and ICP-AES finish).
· These analytical methods are considered as suitable and
appropriate for this type of mineralisation.
· For the 2021 drilling program ALS Mt Isa analysed all samples.
All elements except for gold were analysed by method ME-MS61 (41 element
testing via Aqua Regia digest then ICP-AES) and with any copper assays >1%,
the copper will be redone using method Cu-OG46 with ICP-AES. The gold was done
by method AA25. All methods used were both suitable and appropriate for the
styles of mineralisation present in the Big One Deposit at the time of
sampling.
Regarding the metallurgical testing, a series of rougher tests were carried
out based on the following methodology:
· Sample Preparation and Screening Analysis
· Receive Samples and Inventory
· Control Crush P100 3.35mm (assumed no compositing)
· Rotary Blending & Splitting 1kg charges (12 x 1kg)
· PPS - Head Assay Submission
· Assay - Head Sample (Ag, Au, Co, Cu, SiO2, ICP Scan)
· Flotation and Gravity Testing
· 1 kg Grind Establishment Single grind target
· Rougher Flotation (4 con 1 tail) (5 test allowance)
· PPS - Flotation Product Assay Submission
· Assay - Flotation Products (Ag, Au, Co, Cu, Zn, SiO2)
· Gravity Separation - Wilfley Table - Batch Test
· PPS - Table Product Assay Submission
· Assay - Table Products (Ag, Au, Co, Cu, Zn, SiO2)
· Two runs were established comparing two common froth reagents
(Aerofloat and Danafloat; see main text). Batch froth flotation results were
somewhat affected by remanent drilling foam imbedded in the reverse
circulation chips, as illustrated by the Figure in the previous main text.
· Testing parameters were as noted below:
COMPOSITE Big One BO_318RC
TEST # BF2865, 66
WATER TYPE Perth Tap Water
GRIND SIZE P80 75µm
PULP DENSITY 35%
pH 8.3
Verification of sampling and assaying · The verification of significant intersections by either · All CCZ's DDH and RC hole assay results from ALS have been
independent or alternative company personnel. reviewed by two independent consultant geologists. For current the rock chip
sampling, Independent Laboratory assaying by ALS has confirmed, within
· The use of twinned holes. acceptable limits, the occurrences of high-grade copper inferred from the
initial XRF readings. Laboratory standards and duplicates were used in
· Documentation of primary data, data entry procedures, data accordance with standard procedures for geochemical assaying.
verification, data storage (physical and electronic) protocols.
· Discuss any adjustment to assay data.
Location of data points · Accuracy and quality of surveys used to locate drill holes · All twenty holes done by CCZ in 2021 have had their location
(collar and down-hole surveys), trenches, mine workings and other locations surveyed by GPS and then, at the completion of drilling, were surveyed by
used in Mineral Resource estimation. differential GPS by independent licensed surveyors (GMC Surveys).
· Specification of the grid system used. · The spatial location for these holes has been differentially
surveyed into MGA94 - Zone 54. Collar heights are to the Australian Height
· Quality and adequacy of topographic control. Datum.
· The locations of the 1970 drillholes and 1993 drillholes have
been determined from georeferencing several plans and utilizing tables in
historical reports. Location errors for the 1970 drilling is ±20m whereas
it is about ±12m that for the 1993 holes.
Data spacing and distribution · Data spacing for reporting of Exploration Results. · The final 20 RC holes were part of a 35-hole program that was set
out on a nominal 100m pattern or to redrill 2020 holes that were found to be
· Whether the data spacing, and distribution is sufficient to too short. The 1970 drilling was set at a 30m spacing and the 1993 drilling
establish the degree of geological and grade continuity appropriate for the also at a 50m spacing. At the completion of all the planned holes, the
Mineral Resource and Ore Reserve estimation procedure(s) and classifications drillhole collars were differentially surveyed by an independent, licensed
applied. surveyor and the grid pattern verified. A drone survey over a 2.3Ha area was
flown over the exploration area and covered the outcrop length of the dyke.
· Whether sample compositing has been applied. Data was supplied as spot height clouds, orthophoto and topographic contours
in DXF / DWG format.
Orientation of data in relation to geological structure · Whether the orientation of sampling achieves unbiased sampling of · The 2021 CCZ RC drilling programme (Figure A2-1) has had all
possible structures and the extent to which this is known, considering the holes oriented to intersect the mineralised structure/zone subsurface
deposit type. perpendicularly and therefore does not constitute any perceived bias. The
typical dip direction of the new drillholes is 335-350 deg (Grid North).
· If the relationship between the drilling orientation and the
orientation of key mineralised structures is considered to have introduced a · Rock chip samples have also been taken at areas of interest from
sampling bias, this should be assessed and reported if material. observed mineralisation along the line of lode of the mineralised dyke,
secondary structures, and surrounding spoil heaps.
Sample security · The measures taken to ensure sample security. · Each day's RC samples were removed from site and stored in a
secure location off site.
· The RC chip samples taken were securely locked within the vehicle
on site until delivered to Mt Isa for dispatch to the laboratory in person by
the field personnel.
Audits or reviews · The results of any audits or reviews of sampling techniques and · This was completed once all 20 holes in CCZ's Stage 2021 program,
data. and their assay results have been verified. Additional hyperspectral and XRD
analyses were returned in Feb 2022.
· For the historical drilling, the sampling techniques and the data
generated from the Laboratory Assay results have been peer reviewed by
consultant geologists familiar with the overall Mt Oxide Project and deemed to
be acceptable. To facilitate this, six (6) sites have twinned drillholes,
with the current drilling spudded immediately adjacent to the historical 1970,
1993 and 2020 drilling programs.
Verification of sampling and assaying
· The verification of significant intersections by either
independent or alternative company personnel.
· The use of twinned holes.
· Documentation of primary data, data entry procedures, data
verification, data storage (physical and electronic) protocols.
· Discuss any adjustment to assay data.
· All CCZ's DDH and RC hole assay results from ALS have been
reviewed by two independent consultant geologists. For current the rock chip
sampling, Independent Laboratory assaying by ALS has confirmed, within
acceptable limits, the occurrences of high-grade copper inferred from the
initial XRF readings. Laboratory standards and duplicates were used in
accordance with standard procedures for geochemical assaying.
Location of data points
· Accuracy and quality of surveys used to locate drill holes
(collar and down-hole surveys), trenches, mine workings and other locations
used in Mineral Resource estimation.
· Specification of the grid system used.
· Quality and adequacy of topographic control.
· All twenty holes done by CCZ in 2021 have had their location
surveyed by GPS and then, at the completion of drilling, were surveyed by
differential GPS by independent licensed surveyors (GMC Surveys).
· The spatial location for these holes has been differentially
surveyed into MGA94 - Zone 54. Collar heights are to the Australian Height
Datum.
· The locations of the 1970 drillholes and 1993 drillholes have
been determined from georeferencing several plans and utilizing tables in
historical reports. Location errors for the 1970 drilling is ±20m whereas
it is about ±12m that for the 1993 holes.
Data spacing and distribution
· Data spacing for reporting of Exploration Results.
· Whether the data spacing, and distribution is sufficient to
establish the degree of geological and grade continuity appropriate for the
Mineral Resource and Ore Reserve estimation procedure(s) and classifications
applied.
· Whether sample compositing has been applied.
· The final 20 RC holes were part of a 35-hole program that was set
out on a nominal 100m pattern or to redrill 2020 holes that were found to be
too short. The 1970 drilling was set at a 30m spacing and the 1993 drilling
also at a 50m spacing. At the completion of all the planned holes, the
drillhole collars were differentially surveyed by an independent, licensed
surveyor and the grid pattern verified. A drone survey over a 2.3Ha area was
flown over the exploration area and covered the outcrop length of the dyke.
Data was supplied as spot height clouds, orthophoto and topographic contours
in DXF / DWG format.
Orientation of data in relation to geological structure
· Whether the orientation of sampling achieves unbiased sampling of
possible structures and the extent to which this is known, considering the
deposit type.
· If the relationship between the drilling orientation and the
orientation of key mineralised structures is considered to have introduced a
sampling bias, this should be assessed and reported if material.
· The 2021 CCZ RC drilling programme (Figure A2-1) has had all
holes oriented to intersect the mineralised structure/zone subsurface
perpendicularly and therefore does not constitute any perceived bias. The
typical dip direction of the new drillholes is 335-350 deg (Grid North).
· Rock chip samples have also been taken at areas of interest from
observed mineralisation along the line of lode of the mineralised dyke,
secondary structures, and surrounding spoil heaps.
Sample security
· The measures taken to ensure sample security.
· Each day's RC samples were removed from site and stored in a
secure location off site.
· The RC chip samples taken were securely locked within the vehicle
on site until delivered to Mt Isa for dispatch to the laboratory in person by
the field personnel.
Audits or reviews
· The results of any audits or reviews of sampling techniques and
data.
· This was completed once all 20 holes in CCZ's Stage 2021 program,
and their assay results have been verified. Additional hyperspectral and XRD
analyses were returned in Feb 2022.
· For the historical drilling, the sampling techniques and the data
generated from the Laboratory Assay results have been peer reviewed by
consultant geologists familiar with the overall Mt Oxide Project and deemed to
be acceptable. To facilitate this, six (6) sites have twinned drillholes,
with the current drilling spudded immediately adjacent to the historical 1970,
1993 and 2020 drilling programs.
Table B2-1: Big One Sample for Metallurgical Testing
Borehole Sample # From (m) To (m) Thickness (m) ORIGINAL Weight (kg) COARSE REJECT Weight (kg) Au Ag Cr Co Cu Rb Rock type
BO_318RC CCZ01169 167 168 1.00 2.71 2.21 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01170 168 169 1.00 2.86 2.36 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01171 169 170 1.00 3.01 2.51 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01172 170 171 1.00 3.29 2.79 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01173 171 172 1.00 2.23 1.73 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01174 172 173 1.00 2.50 2.00 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01175 173 174 1.00 2.93 2.43 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01176 174 175 1.00 3.26 2.76 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01177 175 176 1.00 3.01 2.51 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01178 176 177 1.00 3.90 3.40 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01179 177 178 1.00 2.12 1.62 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01180 178 179 1.00 2.70 2.20 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01181 179 180 1.00 2.73 2.23 0.03 0.59 332 184 6553 157 Dacite
BO_318RC CCZ01182 180 181 1.00 3.00 2.50 0.03 0.59 332 184 6553 157 Dacite
14 40.25 33.25
Figure B2-1: Big One Deposit - Location of BO_318RC and Sample for
Metallurgical Testing
Notes: (1) Big One View looking northwest.
(2) Purple bodies are IP anomalies
(3) Assay shown on drillholes is Cu >1,000ppm
Section 2 Reporting of Exploration Results
Criteria JORC Code explanation Commentary
Mineral tenement and land tenure status · Type, reference name/number, location and ownership including · The following mineral tenures are held 100% by subsidiaries of
agreements or material issues with third parties such as joint ventures, Castillo Copper Limited, totalling an area of 736.8 km(2) in the "Mt Oxide
partnerships, overriding royalties, native title interests, historical sites, North Project":
wilderness or national park and environmental settings.
o EPM 26574 (Valparaisa North) - encompasses the Big One historical mineral
· The security of the tenure held at the time of reporting along resource, Holder Total Minerals Pty Ltd, granted 12-June-2018 for a 5-year
with any known impediments to obtaining a licence to operate in the area. period over 100 sub-blocks (323.3Km(2)), Expires 11-June-2023.
o EPM 26462 (Big Oxide North) - encompasses the 'Boomerang' historical mine
and the 'Big One' historical mine, Holder: QLD Commodities Pty Ltd, granted:
29-Aug-2017 for a 5-year period over 67 sub-blocks (216.5 Km(2)), Expires:
28-Aug-2022.
o EPM 26525 (Hill of Grace) - encompasses the Ayra (previously Myally Gap)
significant airborne EM anomaly, Holder: Total Minerals Pty Ltd for a 5-year
period over 38 sub-blocks (128.8Km(2)), Granted: 12-June-2018, Expires:
11-June-2023.
o EPM 26513 (Torpedo Creek/Alpha Project) - Granted 13-Aug-2018 for a 5-year
period over 23 sub-blocks (74.2 Km(2)), Expires 12-Aug-2023; and
o EPM 27440 (The Wall) - An application lodged on the 12-Dec-2019 over 70
sub-blocks (~215 Km(2)) by Castillo Copper Limited. The tenure was granted
on the 18(th of) March 2021.
· This check on the tenures in 'granted' status was completed in
'GeoResGlobe' on the 12(th of) Feb 2022.
Exploration done by other parties · Acknowledgment and appraisal of exploration by other parties. · Historical QDEX / mineral exploration reports have been reviewed
for historical tenures that cover or partially cover the Project Area in this
announcement. Federal and State Government reports supplement the historical
mineral exploration reporting (QDEX open file exploration records).
· Most explorers were searching for Cu-Au-U, and, proving satellite
deposit style extensions to the several small sub-economic copper deposits
(e.g., Big Oxide and Josephine).
· With the Mt Oxide North Project in regional proximity to Mt Isa
and numerous historical and active mines, the Project area has seen portions
of the historical mineral tenure subject to various styles of surface
sampling, with selected locations typically targeted by shallow drilling
(Total hole depth is characteristically less than 50m).
· The Mt Oxide North project tenure package has a significant
opportunity to be reviewed and explored by modern exploration methods in a
coherent package of EPM's, with three of these forming a contiguous tenure
package.
· Various Holders and related parties of the 'Big One' historical
mining tenure (ML8451) completed a range of mining activities and exploration
activities on what is now the 'Big One' prospect for EPM 26574. The
following unpublished work is acknowledged (and previously shown in the
reference list):
o Katz, E., 1970, Report on the Big One, Mt Devine, and Mt Martin Mining
Lease Prospects, Forsayth Mineral Exploration NL, report to the Department of
Mines, CR5353, 63pp
o West Australian Metals NL, 1994. Drill Programme at the "Big One" Copper
Deposit, North Queensland for West Australian Metals NL.
o Wilson, D., 2011. 'Big One' Copper Mine Lease 5481 Memorandum - dated 7
May 2011.
o Wilson, D., 2015. 'Big One' Mining Lease Memorandum - dated 25 May 2015:
and
o Csar, M, 1996. Big One & Mt Storm Copper Deposits. Unpublished field
report.
· The reader of the current ASX Release is referred to the CCZ's
first publication of the 1993 historical reverse circulation drilling results
for additional diagrams and drilling information ("Historic drill data
verifies grades up to 28.40% Cu from <50m in supergene ore at Mt Oxide
Pillar") released on the ASX by CCZ on the 14-January-2020.
· The SRK Independent Geologists Report released by CCZ on the ASX
on 28-July-2020 contains further details on the 'Exploration done by other
parties - Acknowledgment and appraisal of exploration by other parties' this
report is formally titled "A Competent Persons Report on the Mineral Assets of
Castillo Copper Limited" Prepared as part of the Castillo Copper Limited (ASX:
CCZ, LSE: CCZ) LSE Prospectus, with the effective date of the 17-July-2020.
Geology · Deposit type, geological setting, and style of mineralisation. · The Mt Oxide North project is located within the Mt Isa Inlier of
western Queensland, a large, exposed section of Proterozoic (2.5 billion- to
540-million-year-old) crustal rocks. The inlier records a long history of
tectonic evolution, now thought to be like that of the Broken Hill Block in
western New South Wales.
· The Mt Oxide North project lies within the Mt Oxide Domain,
straddling the Lawn Hill Platform and Leichhardt River Fault Trough. The
geology of the tenement is principally comprised of rocks of the Surprise
Creek and Quilalar Formations which include feldspathic quartzites,
conglomerates, arkosic grits, shales, siltstones and minor dolomites and
limestones.
· The Project area is cut by a major fault zone, trending north-
northeast - south- southwest across the permits. This fault is associated with
major folding, forming several tight synclines- anticline structures along its
length.
· The Desktop studies commissioned by CCZ on the granted mineral
tenures described four main styles of mineralisation account for most mineral
resources within the rocks of the Mt Isa Province (after Withnall &
Cranfield, 2013).
o Sediment hosted silver-lead-zinc - occurs mainly within fine-grained
sedimentary rocks of the Isa Super basin within the Western Fold Belt.
Deposits include Black Star (Mount Isa Pb-Zn), Century, George Fisher North,
George Fisher South (Hilton) and Lady Loretta deposits.
o Brecciated sediment hosted copper - occurs dominantly within the
Leichhardt, Calvert, and Isa Super basin of the Western Fold Belt, hosted in
brecciated dolomitic, carbonaceous, and pyritic sediments or brecciated rocks
proximal to major fault/shear zones. Includes the Mount Isa copper orebodies
and the Esperanza/Mammoth mineralisation.
o Iron-oxide-copper-gold ("IOCG") - predominantly chalcopyrite-pyrite
magnetite/hematite mineralisation within high grade metamorphic rocks of the
Eastern Fold Belt. Deposits of this style include Ernest Henry, Osborne, and
Selwyn; and
o Broken Hill type silver-lead-zinc - occur within the high-grade
metamorphic rocks of the Eastern Fold Belt. Cannington is the major example,
but several smaller currently sub-economic deposits are known.
· Gold is primarily found associated with copper within the IOCG
deposits of the Eastern Fold Belt. However, a significant exception is noted
at Tick Hill where high grade gold mineralisation was produced, between 1991
and 1995 by Carpentaria Gold Pty Ltd, some 700 000 tonnes of ore was mined at
an average grade of 22.5 g/t Au, producing 15 900 kg Au. The Tick Hill deposit
style is poorly understood (Withnall & Cranfield, 2013).
· ROM Resources had noted in a series of recent reports for CCZ on
the granted tenures, that cover the known mineralisation styles including:
o Stratabound copper mineralisation within ferruginous sandstones and
siltstones of the Surprise Creek Formation.
o Disseminated copper associated with trachyte dykes.
o Copper-rich iron stones (possible IOCG) in E-W fault zones; and
o possible Mississippi Valley Type ("MVT") stockwork sulphide mineralisation
carrying anomalous copper-lead-zinc and silver.
· The Mt Oxide and Mt Gordon occurrences are thought to be breccia
and replacement zones with interconnecting faults. The Mt Gordon/Mammoth
deposit is hosted by brittle quartzites, and Esperanza by carbonaceous shales.
Mineralisation has been related to the Isan Orogeny (1,590 - 1,500 Ma).
· Mineralisation at all deposits is primarily
chalcopyrite-pyrite-chalcocite, typically as massive sulphide within breccias.
· At the Big One prospect, West Australian Metals NL described the
mineralisation as (as sourced from the document "West Australian Metals NL,
1994. Drill Programme at the "Big One" Copper Deposit, North Queensland for
West Australian Metals NL."):
o The targeted lode / mineralised dyke is observable on the surface. The
mineralisation targeted in the 1993 drilling programmed is a supergene copper
mineralisation that includes malachite, azurite, cuprite, and tenorite, all
associated with a NE trending fault (062(o) to 242(o)) that is intruded by a
porphyry dyke.
o The mineralised porphyry dyke is vertical to near vertical (85(o)), with
the 'true width' dimensions reaching up to 7m at surface.
o At least 600m in strike length, with strong Malachite staining observed
along the entire strike length, with historical open pits having targeted
approximately 200m of this strike. Exact depth of mining below the original
ground surface is not clear in the historical documents, given the pits are
not battered it is anticipated that excavations have reached 5m to 10m beneath
the original ground surface.
o Associated with the porphyry dyke are zones of fractured and/or sheared
rock, the siltstones are described as brecciated, and sandstones around the
shear as carbonaceous.
o The known mineralisation from the exploration activities to date had
identified shallow supergene mineralisation, with a few drillholes targeting
deeper mineralisation in and around the 200m of strike historical open cut
pits.
o A strongly altered hanging wall that contained malachite and cuprite
nodules. Chalcocite mineralization has been identified but it is unclear on
the prevalence of the Chalcocite; and
o The mineralisation was amenable to high grade open pit mining methods of
the oxide mineralization (as indicated by numerous historical open pit shallow
workings into the shear zone).
· Desktop studies commissioned by CCZ and completed by ROM
Resources and SRK Exploration have determined that the Big One prospect is
prospective for Cu, Co, and Ag.
· Desktop studies commissioned by CCZ have determined the Boomerang
prospect contains:
o Secondary copper staining over ~800m of strike length.
o Associated with a major east-west trending fault that juxtaposes the upper
Surprise Creek Formation sediments against both the underlying Bigie Formation
and the upper Quilalar Formation units.
· At the 'Flapjack' prospect there is the additional potential for:
o Skarn mineralisation for Cu-Au and/or Zn-Pb-Cu from replacement carbonate
mineralisation, particularly the Quilalar Formation.
o Thermal Gold Auroele mineralisation is a potential model due to the high
silica alteration in thermal aureole with contact of A-Type Weberra Granite -
related to the Au mineralisation; and/or
o IOCG mineralisation related to chloride rich fluids.
· At the 'Crescent' prospect there is the additional potential for:
o Skarn mineralisation for Cu-Au and/or Zn-Pb-Cu from replacement carbonate
mineralisation, particularly the Quilalar Formation; and/or
o Thermal Gold Auroele mineralisation is a potential model due to the high
silica alteration in thermal aureole with contact of A-Type Weberra Granite -
related to the Au mineralisation; and
o IOCG mineralisation related to potassic rich fluids.
· At the 'Arya' prospect there is the additional potential for:
o Supergene mineralisation forming at the surface along the fault, fault
breccia, and the Surprise Creek Formation 'PLrd' rock unit ('Prd' historical).
o Epigenetic replacement mineralisation for Cu (with minor components of
other base metals and gold) from replacement carbonate mineralisation,
particularly the Surprise Creek Formation.
o Skarn mineralisation for Cu-Au and/or Zn-Pb-Cu from replacement carbonate
mineralisation, particularly the Surprised Creek Formation.
o Sulphide mineralisation within breccia zones, along stress dilation
fractures, emplaced within pore spaces, voids, or in other rock fractures;
and/or
o IOCG mineralisation related to chloride rich fluids.
· A selection of publicly available QDEX documents / historical
exploration reports have been reviewed, refer to Section 2, sub-section
"Further Work" for both actions in progress and proposed future actions.
· The SRK Independent Geologists Report released by CCZ on the ASX
on 28-July-2020 contains further details on the 'Geology - Deposit type,
geological setting and style of mineralisation': this report is formally
titled "A Competent Persons Report on the Mineral Assets of Castillo Copper
Limited" Prepared as part of the Castillo Copper Limited (ASX: CCZ, LSE: CCZ)
LSE Prospectus, with the effective date of the 17-July-2020.
Drill hole Information · A summary of all information material to the understanding of the · For the 2021 program, all drillhole information was coded to the
exploration results including a tabulation of the following information for same formatted spreadsheets used by CCZ, being hand-encoded from hard-copy
all Material drill holes: reports, plans, and cross-sections.
o easting and northing of the drill hole collar · For CCZ's current drilling program, this information has been
recorded in formatted spreadsheets during the drilling and will be checked and
o elevation or RL (Reduced Level - elevation above sea level in metres) of verified at the conclusion of the current program. The 2021 reported holes
the drill hole collar (315-334DD) are listed in previous drilling collars listed in the 11(TH) and
26th July ASX release and (in Tables B2-2 and B2-3) and in the maiden ASX
o dip and azimuth of the hole release on the 28(th) February 2022.
o down hole length and interception depth
o hole length.
· If the exclusion of this information is justified on the basis
that the information is not Material and this exclusion does not detract from
the understanding of the report, the Competent Person should clearly explain
why this is the case.
Data aggregation methods · In reporting Exploration Results, weighting averaging techniques, · Queries on some assays from CCZ's current drilling program were
maximum and/or minimum grade truncations (e.g., cutting of high grades) and resolved in January 2022.
cut-off grades are usually Material and should be stated.
· For historical surface sampling, Independent Laboratory Assay
· Where aggregate intercepts incorporate short lengths of results for soil and rock chip samples from the Big One Deposit were averaged
high-grade results and longer lengths of low-grade results, the procedure used if more than one reading or determination was given.
for such aggregation should be stated and some typical examples of such
aggregations should be shown in detail. · Copper grades were reported in this ASX release as per the
received laboratory report, i.e., there was no cutting of high-grade copper
· The assumptions used for any reporting of metal equivalent values results as they are directly relatable to high grade mineralisation styles
should be clearly stated. readily visible in the relevant samples and modelling methodologies employed
used lower cut-off grades and suitable top-cuts.
· There were no cut-off grades factored into any assay results
reported, however once modelling commences a high cut-off grade of 10,000ppm
or 10% copper will be used.
Relationship between mineralisation widths and intercept lengths · These relationships are particularly important in the reporting · When available, all mineralised intervals (i.e., >500ppm) have
of Exploration Results. been reported in this and previous ASX releases as the "as-intersected"
apparent thickness (in metres) and given that most drillholes dip at -60 to
· If the geometry of the mineralisation with respect to the drill -70 degrees from the horizontal, true intersection widths will be calculated
hole angle is known, its nature should be reported. during the block modelling process.
· If it is not known and only the down hole lengths are reported,
there should be a clear statement to this effect (eg 'down hole length, true
width not known').
Diagrams · Appropriate maps and sections (with scales) and tabulations of · This part will be done once CCZ's current drilling program is
intercepts should be included for any significant discovery being reported completed, and all samples have been assayed and verified.
These should include, but not be limited to a plan view of drill hole collar
locations and appropriate sectional views. · Appropriate diagrams are presented in the body and the Appendices
of the current ASX Release. Where scales are absent from the diagram, grids
have been included and clearly labelled to act as a scale for distance.
· Maps and Plans presented in the current ASX Release are in MGA94
Zone 54, Eastings (mE), and Northing (mN), unless clearly labelled otherwise.
· A series of cross-sections have been generated at Big One
displaying copper analyses in ppm to aid interpretation and exploration
planning (in previous ASX releases in July and August 2021)
Balanced reporting · Where comprehensive reporting of all Exploration Results is not · Comprehensive reporting was undertaken for the EPM 26574
practicable, representative reporting of both low and high grades and/or 2020-2021 Annual Report and documentation associated with the mineral resource
widths should be practiced avoiding misleading reporting of Exploration estimate.
Results.
· Appropriate diagrams are presented in the body and the Appendices
of the current ASX Release. Where scales are absent from the diagram, grids
have been included and clearly labelled to act as a scale for distance.
Other substantive exploration data · Other exploration data, if meaningful and material, should be · Several airborne EM and magnetic surveys have been conducted
reported including (but not limited to): geological observations; geophysical nearby by historical explorers and Castillo Copper has conducted its own
survey results; geochemical survey results; bulk samples - size and method of surface sampling program prior to drilling commencing as noted above. A
treatment; metallurgical test results; bulk density, groundwater, geotechnical major IP survey was completed during May 2021 across five (5) north-east
and rock characteristics; potential deleterious or contaminating substances. trending survey lines (dipole-dipole array). Historical work has focussed on
drilling and geochemical sampling, with no detailed geophysical data
collection. The copper intersected to date appears to be associated with a
NE-SW trending dyke. It occurs in two zones - oxidised (malachite, azurite,
tenorite, cuprite) and chalcocite. The aim of the IP survey was to ascertain
if the copper mineralisation intersected to date has a discernible electrical
response (chargeable and / or conductive). If so, it is hoped that other zones
of similar electrical response can be highlighted to better focus the upcoming
drill program.
As a result of the evaluation of data from the IP surveys carried out, the
following recommendations by consultancy GeoDiscovery were made:
· The 2D section models are likely to give the most accurate
representation of the earth's conductivity and chargeability variations and
should be used when drill targeting. The 3D model output allows trends and
structures to be mapped and may give some indications of off-line anomalies.
· 50m DP-DP is shown to be a cost-effective method to cover ground
relatively quickly and map the electrical properties of the top 150m or so. If
drill testing the regions of elevated chargeability proves successful, a
larger 100m DP-DP or P-DP campaign may be considered to cover more ground and
to greater depth.
· Incorporate the 3D and 2D IP models into the available geological
database to determine the extent to which the chargeable zones may or may not
have been tested, as well as their geological / stratigraphic significance.
· It is recommended that where IP anomalies occur near surface, a
field visit is undertaken to see if anomaly can be explained by surficial
clays / lithology.
Further work · The nature and scale of planned further work (e.g., tests for · Future potential work is described within the body of the ASX
lateral extensions or depth extensions or large-scale step-out drilling). Release, and will include:
· Diagrams clearly highlighting the areas of possible extensions, o A third drilling campaign to extend known mineralisation via focusing on a
including the main geological interpretations and future drilling areas, sizeable known bedrock conductor north of the line of lode and incremental
provided this information is not commercially sensitive. geophysical surveys to identify fresh targets.
o Detailed mapping and rock chip sampling.
o Detailed surface gravity and magnetic surveys.
o Diamond Coring.
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