Atacama Pacific Announces Continued Positive Metallurgical Results
From Cerro Maricunga Oxide Gold Project
TORONTO, ONTARIO--(Marketwired - Jun 9, 2014) - Atacama Pacific
Gold Corporation (TSX-VENTURE:ATM) ("Atacama Pacific") is pleased
to report the results from six column percolation leach tests
completed on gold mineralization from its Cerro Maricunga oxide
gold deposit located in northern Chile. The tests were undertaken
to compare the gold recoveries from mineralization crushed to
different sizes and to examine the impact of crushing using high
pressure grind rolls ("HPGR") on recoveries. The test work also
examined the impact of reducing the amount of lime used to control
leach solution pH.
Table 1 summarizes the results of the column tests. Highlights
from the current test work include:
- Only a minor decrease in gold recoveries was observed when
increasing crush size to 105 mm.
- HPGR crushed mineralization did not achieved significantly
higher gold recoveries compared to conventionally crushed
material.
- Majority of leachable gold was extracted in the first twenty
days at crush sizes less than 21 mm.
Table 1 - Summary of Column Test Results, Cerro
Maricunga Deposit |
Test # |
Head Grade |
Gold Recovery |
Crush Size |
NaCN1 |
Lime + Cement2 |
Note |
(g/t Au) |
(%) |
(P80 = mm) |
(kg/t) |
(kg/t) |
68801A |
0.33 |
72 |
105.0 |
0.96 |
1.0 |
Conventionally crushed |
68801B |
0.33 |
74 |
21.0 |
1.96 |
1.8 |
Conventionally crushed |
68811 |
0.44 |
83 |
7.6 |
2.42 |
2.0 |
Conventionally crushed |
68815 |
0.44 |
84 |
7.2 |
2.10 |
1.9 |
HPGR |
68813 |
0.58 |
86 |
6.4 |
2.47 |
1.8 |
HPGR |
68814 |
0.58 |
84 |
6.9 |
2.24 |
1.8 |
HPGR, fines processed separately |
1. Reduced levels of lime resulted in a tripling of
NaCN consumption due to the loss of solution pH control |
2. Totals include 1 kg of cement |
The current testing examined the impact of reducing the initial
amount of lime added to the columns, which has a direct impact on
leach solution pH and NaCN consumption. The solution pH of the
current tests averaged between 9.0 and 9.5 resulting in
significantly higher than previously determined NaCN consumption.
The solution pH of all previous columns had been maintained between
10 and 11 establishing heap leach NaCN consumption in the order of
0.24 kg/t.
Test Results
As confirmed by column tests 68801A and 68801B, coarser crushed
mineralization achieved slightly lower gold recoveries (72% at a
105 mm crush versus 74% at a 21 mm crush) similar to earlier column
test results. Previous testing undertaken on mineralization crushed
to 19 mm achieved gold recoveries of 78 to 89% compared to
recoveries of 76 to 80% from mineralization crushed between 50 and
150 mm.
Three tests were completed on material crushed with HPGR
following up on a HPGR-related column test announced on May 9, 2013
which attained a gold recovery of 85%. The current tests achieved
gold recoveries varying from 84% to 86%. Two columns, completed on
the same sample material, examined the impact of HPGR and
conventional crushing with the HPGR test (68815) achieving 84%
recoveries and the conventional test achieving 83% recoveries.
There appears to be no significant benefit to using HPGR
crushing.
Metallurgical Test
Details
The column tests, conducted by Kappes, Cassidy and Associates,
Reno, Nevada, were run 84 days. Table 2 summarizes the test
details. Column slump, the difference between the initial sample
height in a column compared to the height after test completion,
was low. The initial leach solution for each column test contained
1.0 g NaCN/l and an on-flow solution NaCN concentration of 0.6 g/l
was maintained during the test period.
Table 2 - Column Test Details |
Test # |
Head Grade |
Gold Recovery |
Test Period |
Crush Size |
Dry Weight |
Initial Height |
Final Height |
Column Slump |
(g/t Au) |
(%) |
days |
(P80= mm) |
kg |
m |
m |
% |
68801A |
0.33 |
72 |
84 |
105.0 |
699 |
3.09 |
3.07 |
0.6 |
68801B |
0.33 |
74 |
84 |
21.0 |
49 |
2.02 |
2.00 |
0.9 |
68811 |
0.44 |
83 |
84 |
7.6 |
49 |
1.77 |
1.73 |
1.8 |
68815 |
0.44 |
84 |
84 |
7.2 |
55 |
1.93 |
1.90 |
2.0 |
68813 |
0.58 |
86 |
84 |
6.4 |
55 |
1.91 |
1.88 |
2.0 |
68814 |
0.58 |
84 |
84 |
6.9 |
55 |
1.91 |
1.87 |
1.3 |
Prefeasibility Update
The Cerro Maricunga prefeasibility study is progressing well.
The mineral processing and the majority of the mining plans have
been completed and Atacama Pacific is waiting for supplier quotes
for fleet equipment and some infrastructural items. All quotes are
expected prior to the end of June and the PFS should be available
for release in early July 2014.
Share Issuance
As announced on May 15, 2014, Atacama Pacific entered into an
agreement with Hydro Exploraciones SpA under which it agreed to
issue 350,000 common shares at a price of $1.15 per share to settle
all obligations under two water exploration agreements. These
agreements are related to water concessions located 70 km to the
east of the Cerro Maricunga and subject to a water exploration
joint venture agreement with Exeter Resources Corporation. These
shares were issued on June 6, 2014 following approval of the
transaction by the TSX Venture Exchange. The hold period on these
shares will expire on October 7, 2014.
About Atacama Pacific Gold Corporation
Atacama Pacific's primary mineral property is the Cerro
Maricunga oxide-associated, breccia-hosted gold project, located in
Region III, 140 kilometres by road northeast of the city of
Copiapo. In Atacama Pacific's January 2013 PEA envisions a large
open pit operation mining 80,000 tonne per day with a conventional
heap leach processing facility producing 2.7 million ounces of gold
over a 10 year mine life with cash costs of US$652 per ounce. On
January 28, 2014, Atacama Pacific announced an updated pit confined
resource estimate of 3.47 million ounces of gold (248.8 million
tonnes grading 0.43 g/t gold) in the measured and indicated
category with a further 0.043 million ounces (3.1 million tonnes
grading 0.43 g/t gold) in the inferred category. The resource
estimate was based upon a cut-off grade of 0.18 g/t gold.
National Instrument
43-101
As defined by Section 1.5 of National Instrument 43-101 ("NI
43-101") of the Canadian Securities Administrators, the Qualified
Person for the Cerro Maricunga Property is Sergio Diaz, a resident
of Santiago, Chile and a registered member of the "Comisión
Calificadora de Competencias en Recursos y Reservas Mineras"
(Chilean Mining Commission, registry n° 051), an accepted foreign
association as defined by NI 43-101 (Appendix A). Mr. Diaz has
reviewed the contents of this press release.
The Cerro Maricunga resource estimate was prepared under CIM
Definition Standards (2005). Dr. Eduardo Magri, a mining engineer
(University of Witwatersrand) and a Fellow of the Southern African
Institute of Mining and Metallurgy with over 30 years of industry
experience, is the Independent Qualified Person for the resource
estimate.
FORWARD-LOOKING STATEMENTS
This news release contains forward-looking statements, including
predictions, projections and forecasts. Forward-looking statements
include, but are not limited to, statements with respect to the
PEA, including the potential total gold production of 2.7 million
ounces over a 10.1 year mine life, initial life of mine estimated
operating cash costs of US$652/oz Au, preliminary initial capital
cost estimate of US$514.6 million with sustaining capital of
US$249.0 million, pre-tax pay-back period of 2.5 years at
US$1,450/oz Au and 1.7 years at US$1,700/oz Au, pre-tax NPV of $741
million at US$1,450/oz Au and a 5% discount rate After-tax NPV5% of
US$531 million, pre-tax NPV5% of US$1,247 million and an after-tax
NPV5% of US$923 million at US$1,700/oz Au, pre-tax IRR) of 33.9% at
US$1,450/oz Au (after-tax IRR of 26.6%), statements regarding the
expectation to increase mineral resources, statements regarding
expectations for receipt of permits and environmental approvals,
exploration results (including with respect to water resources),
the success of exploration activities generally, mine development
prospects, and potential future gold production. Often, but not
always, forward-looking statements can be identified by the use of
words such as "plans", "planning", "expects" or "does not expect",
"continues", "scheduled", "estimates", "forecasts", "intends",
"potential", "anticipates", "does not anticipate", or "belief", or
describes a "goal", or variation of such words and phrases or state
that certain actions, events or results "may", "could", "would",
"might" or "will" be taken, occur or be achieved.
Forward-looking statements involve known and unknown risks,
future events, conditions, uncertainties and other factors which
may cause the actual results, performance or achievements to be
materially different from any future results, prediction,
projection, forecast, performance or achievements expressed or
implied by the forward-looking statements. Such factors include,
among others, the results of due diligence activities, changes in
economic parameters and assumptions, the interpretation and actual
results of current exploration activities; changes in project
parameters as plans continue to be refined; the results of
regulatory and permitting processes; future prices of gold;
possible variations in grade or recovery rates; failure of
equipment or processes to operate as anticipated; labour disputes
and other risks of the mining industry; the results of further
economic and technical studies, delays in obtaining governmental
approvals or financing or in the completion of exploration, as well
as those factors disclosed in Atacama Pacific's publicly filed
documents.
Although Atacama Pacific has attempted to identify important
factors that could cause actual actions, events or results to
differ materially from those described in forward-looking
statements, there may be other factors that cause actions, events
or results not to be as anticipated, estimated or intended. There
can be no assurance that forward-looking 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.
Neither the TSX
Venture Exchange nor its Regulation Services Provider (as that term
is defined in the policies of the TSX Venture Exchange) accepts
responsibility for the adequacy or accuracy of this release.
Atacama Pacific Gold CorporationCarl B. HansenPresident and
CEO416 861 8267416 861
9116info@atacamapacific.comwww.atacamapacific.com
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