Altamira Gold Reports over 90% Gold Recoveries from Initial Metallurgical Tests on Drill Samples from the Maria Bonita Target, Cajueiro Project, Brazil
Altamira Gold Reports over 90% Gold
Recoveries from Initial Metallurgical Tests on
Drill Samples from the Maria Bonita Target,
Cajueiro Project, Brazil
Vancouver, British Columbia--(Newsfile Corp. - March 2, 2023) -
Altamira Gold Corp. (TSXV: ALTA)
(FSE: T6UP) (OTC Pink: EQTRF),
("
Altamira
" or the "
Company
") is pleased to announce that it has
received the results of initial metallurgical characterisation tests on two composite drill core samples
from the recently completed scout diamond drill campaign at the Maria Bonita target within the Cajueiro
project in Para state, Brazil.
Highlights:
Cyanide leach in a 24-hour agitated leach test at a grind size of 80% passing the 75µm screen
recovered
92% of total gold content
in a saprolite composite (oxide) sample, while the fresh
rock composite sample recovered
90% of gold content
.
Drill assay composite head grades for the saprolite (1.2g/t gold) and fresh rock (1.1g/t gold)
correspond well with the laboratory head grades of 1.3g/t and 1.07g/t gold respectively.
Average cyanide (0.11kg/t) consumptions were very low by industry standards (0.45-0.75kg/t) as a
result of very low sulphide contents in the mineralized material.
Consulting metallurgist Ian Gordon Hall Dun BSc (Eng), MSc. (who has 45 years of experience as a
metallurgist in Brazil) observed, "The main body of tests were conducted at a specialist laboratory in
Brazil (Testwork Desenvolvimento de Processo Ltda) which is highly regarded for its evaluation of
gold ores. Initial results show excellent gold recoveries from both the saprolite and hard rock samples
in an agitated cyanide leach test. These initial results point successfully in the direction of a heap
leach scenario with high Au recovery and modest reagent consumptions. More laboratory testing will
now be focused on that heap leach scenario."
Altamira Gold President and CEO, Michael Bennett, commented, "The excellent assay results from
the initial drillholes at Maria Bonita were sufficiently encouraging for us to immediately commission
metallurgical tests on the mineralized material. We are very pleased with these initial test results as
they show the potential for high gold recoveries in the 90% range for both saprolite and fresh rock.
Importantly, key leach reagent consumptions were low and the tests confirmed that the mineralization
does not contain significant deleterious elements. With these positive metallurgical results in hand,
we will continue the planning of a follow up drill campaign aimed at determining the size of the
mineralized body."
CAJUEIRO PROJECT
The Cajueiro project is located approximately 75km NW of the town of Alta Floresta in the state of Mato
Grosso (Figure 1) in central western Brazil and is easily accessible by road and has grid power.
Cajueiro forms one of three key projects that Altamira controls in the region, the other two being Apiacas
and Santa Helena (Figure 1).
Figure 1: Location of the Cajueiro, Apiacas and Santa Helena projects.
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The Cajueiro project has current NI 43-101 resources of 5.66Mt @ 1.02 g/t gold for a total of 185,000 oz
in the Indicated Resource category and 12.66Mt @ 1.26 g/t gold for a total of 515,000 oz in the Inferred
Resource category.
Several strong mainly untested gold-in-soil anomalies occur within a short radius of the Cajueiro
resource area and include Maria Bonita, Sossego and Novo Sonho (Figure 2). Maria Bonita is the
strongest of these peripheral gold-in-soil anomalies and is open to the west, with the current footprint of
the geochemical anomaly covering an area comparable in size to the entire Cajueiro mineral resource
area.
Figure 2: Location of the Cajueiro (Baldo) mineral resource and the Maria Bonita target showing
relative size and intensity of the soil responses. The Maria Bonita soil anomaly remains open to the
west and north.
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Maria Bonita Target
The Maria Bonita target is located approximately 7km northwest of the Cajueiro resource area (Figure 2)
and is defined by a gold-in-soil anomaly which is at least 800 x 800m in size and open to the west. The
central part of the anomaly returned gold values in excess of 1g/t gold in soils (Figure 3).
Figure 3: Gold-in-soil values at the Maria Bonita target over background aero-magnetic data
(derivative of total magnetic intensity - TMI) with structural interpretation.
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Following completion of holes MBA001-MBA004 (see press releases dated September 7 and
November 16, 2022), representative composite samples of saprolite and fresh rock were prepared from
assay sample coarse rejects, returned from the analytical laboratory. Each sample weighed 20kg and
was comprised of 15 subsamples of individual core intervals, each of which measured 0.77-1.5m.
The calculated head grades from prior assay results were 1.2g/t Au for the saprolite and 1.1g/t Au for the
fresh rock samples.
The samples were submitted to Testwork Desenvolvimento de Processo Ltda in Nova Lima, Minas
Gerais, Brasil. The testwork was conducted under the observation of the Company's consulting
metallurgist Ian Gordon Hall Dun BSc (Eng), MSc. who specialises in gold and tin processing and has
wide experience in Latin American projects, having resided in the region for 45 years.
Au g/t
>35#
<35#
Calc head
Est head
Saprolite
1.39
1.24
1.30
1.2
Fresh Rock
0.91
1.15
1.07
1.1
Table 1: Estimated head grades (from drill assay composites) versus calculated head grades (from
laboratory sizing analysis)
The laboratory calculated head grades for the samples were 1.30g/t Au and 1.07g/t Au respectively
which correlate well with the estimated head grades from the individual drill core residue composites.
The testwork programme included leaching, gravity, magnetic and froth flotation characterisation tests.
The samples were submitted in a crushed state, nominally passing 3mm. A screening of a 3kg sub-
sample of the head material at 35# (500µm), showed that 43% (saprolite) and 72% (fresh rock) of the
contained gold is in the <35# fraction.
The sample material was reduced to 80% passing 75µm for successive tests.
Direct agitated leaching tests were conducted on two sub-samples of each main sample (saprolite and
fresh rock). The results showed 89.9 to 92.8% gold recoveries at low reagent consumption rates as
outlined below.
Au recovery %
Test 1
Test 2
Saprolite
91.3
92.8
Fresh Rock
89.9
90.5
Table 2: Gold recovery from direct leach tests
Lime kg/t
Na CN g/t
Test 1
Test 2
Test 1
Test 2
Saprolite
4.5
4.2
284
220
Fresh Rock
0.8
0.75
88
92
Table 3: Main reagent consumption for direct leach tests
Industry average cyanide (CN) consumption rates generally lie in the range 450-750g/t (grams per tonne
of ore treated). Therefore, the initial tests are highly encouraging that a low cyanide consumption may be
anticipated. Consumption of lime for pH modification in fresh rock is also well below an industry
benchmark of ~2kg/t.
A combination of gravity and flotation tests produced average gold recoveries of 68% (fresh) and 69%
(saprolite), which suggest that further work is warranted via those routes to optimise a metallurgical plan,
underpinned by the 90% recoveries obtained from direct leaching.
As a next-step, the Company plans to conduct preliminary tests on crushing and grinding characteristics
plus amenability of the leach dynamics to heap leaching.
Qualified Person
Guillermo Hughes, FAIG and M AusIMM., a consultant to the Company as well as a Qualified Person as
defined by National Instrument 43-101, supervised the preparation of the technical information in this
news release.
About Altamira Gold Corp.
The Company is focused on the exploration and development of gold projects within western central
Brazil. The Company holds 8 projects comprising approximately 190,000 hectares, within the prolific
Juruena gold belt which historically produced an estimated 7 to 10Moz of placer gold. The Company's
advanced Cajueiro project has NI 43-101 resources of 5.66Mt @ 1.02 g/t gold for a total of 185,000 oz
in the Indicated Resource category and 12.66Mt @ 1.26 g/t gold for a total of 515,000oz in the Inferred
Resource category.
On Behalf of the Board of Directors,
ALTAMIRA GOLD CORP.
"Michael Bennett"
Michael Bennett
President & CEO
Tel: 604.676.5660
Toll-Free:1-833-606-6271
www.altamiragold.com
Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in
policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this
release.
The securities described herein have not been registered under the U.S. Securities Act or any state
securities laws, and may not be offered or sold in the United States absent registration or an
applicable exemption from registration requirements under the U.S. Securities Act and any applicable
state securities laws.
Forward-looking Statements
Certain information contained herein constitutes "forward-looking information" under Canadian
securities legislation.
Forward-looking information includes, but is not limited to, statements with
respect to the extension of the Warrants.
Generally, forward-looking information can be identified by
the use of forward-looking terminology such as "will", "intends" or variations of such words and
phrases or statements that certain actions, events or results "will" occur.
Forward-looking statements
are based on the opinions and estimates of management as of the date such statements are made
and they are subject to known and unknown risks, uncertainties and other factors that may cause the
actual results to be materially different from those expressed or implied by such forward-looking
statements or forward-looking information, including the receipt of all necessary regulatory approvals.
Although management of the Company has attempted to identify important factors that could cause
actual results to differ materially from those contained in forward-looking statements or forward-looking
information, there may be other factors that cause results not to be as anticipated, estimated or
intended.
There can be no assurance that such statements will prove to be accurate, as actual results
and future events could differ materially from those anticipated in such statements.
Accordingly,
readers should not place undue reliance on forward-looking statements and forward looking
information.
The Company will not update any forward-looking statements or forward-looking
information that is incorporated by reference herein, except as required by applicable securities laws.
Notes
Gold analysis has been conducted by SGS method FAA505 (fire assay of 50g charge), with higher
grade samples checked by FAA525. Analytical quality is monitored by certified references and
blanks. Until dispatch, samples are stored under the supervision the Company's exploration office.
The samples are couriered to the assay laboratory using a commercial contractor. Pulps are returned
to the Company and archived. Drill holes results are quoted as down-hole length weighted
intersections.
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