Vancouver, BC – Los Andes Copper Ltd. (“Los Andes” or the “Company”, TSX
Venture Exchange: LA) is pleased to present an update on the work conducted in
order to progress the Pre-Feasibility Study (“PFS”) on the Company’s Vizcachitas
Project (“Vizcachitas” or the “Project”).
The Preliminary Economic Assessment (PEA) delivered in June 2019 provided a
conceptual plan for developing the Vizcachitas Project. A PFS is currently
underway and areas of work being advanced include, processing, tailings facility,
infrastructure, geology, mine plan, environment and social and community
The current COVID-19 situation, while delaying some of the metallurgical testwork
and field work, has not delayed the progress of the main engineering study. All
employees and subcontractors are working from home where possible and only a
small group of individuals are working to prepare samples in the Company’s
Santiago core storage area.
Highlights of the main advances in the PFS
• Testwork has shown that a HPGR circuit is feasible for the Project and could
provide enhanced project economics with lower energy consumption and
increased operating flexibility.
• The mineral is amenable to filtering and dry-stack tailings. This change
would significantly reduce the Project’s water consumption, footprint and
• Due to the reduced footprint required for dry stacked tailings, it is possible
to have all project infrastructure in one operating complex in the Rocin
Valley. The PEA outlined infrastructure in both the Rocin Valley and the
Fernando Porcile, Executive Chairman of Los Andes, commented:
“I am delighted that we are continuing to make significant progress with the PFS
during these difficult times.
“The results from the testwork carried out to date are encouraging and now with
the approval of the environmental declaration for the PFS drill programme allowing
us to carry out further drilling in the coming months, we will be able to complete
certain other aspects of the study, therefore further contributing to the delivery of
a robust PFS.”
“I look forward to keeping the market up to date with our progress.”
Studies on the feasibility of using a HPGR circuit are progressing and show the
potential for enhanced project economics, lower energy consumption, reduced
maintenance and increased operational flexibility. HPGR technology has been
identified as the most attractive grinding alternative, given the data obtained from
the preliminary testwork conducted to date.
The flotation optimisation testwork conducted to date has shown revised conditions
(when compared to the PEA) which should increase overall copper and
molybdenum recoveries by improving floatability with reduced grinding
requirements. Flotation testing was conducted on the “Upper Zone” composite
from the 2018 testwork which had the lowest metallurgical recoveries from those
The mineral characterisation carried out in 2017-2019 on over 80 variability
samples showed that the mineralized rock, with copper head grades between 0.18
– 1.00%, molybdenum head grades between 30 – 500 ppm, had a low presence
of clays (mainly kaolinite), favouring flotation and water recovery performance.
The settling and filtering testwork conducted to date is indicating that filtered drystacked tailings are a viable alternative to thickened tailings. The 2019 laboratory
settling testwork with four composite samples from the 2018 testwork shows good
settling rates for tailings, even for the worst samples. The Vizcachitas
mineralisation has favorable filtration rates suitable for belt filters. Nevertheless,
belt filters are being considered in combination with pressure filters to treat the
finer fraction of tailings and retain excess filtering capacity to reduce operational
Dry-stacked tailings would:
• Reduce water consumption by approximately 50%
• Reduce the Project’s footprint
• Be better suited for areas of high seismic activity
• Be transported by trucks or conveyors
• Eliminate the need for a traditional dam wall
• Reduce the environmental risk by avoiding contact with ground water
All the project infrastructure is located in the Rocin Valley, reducing the Project’s
footprint and environmental impact.
• The PFS layout has the crushing and grinding area built over a mine waste
backfill platform close to the mine and the concentrator is built on the east
side of the Rocin Valley. CAPEX related to excavations and earthworks is
reduced as pre-stripping is used as the backfill.
• Dry filtered tailings are stacked within the Rocin Valley.
• A 220 kV power line would be routed to a substation near the city of Los
Andes, reducing its length from a 105 km line in the PEA to 65 km line.
• The concentrate would be loaded into sealed contains (Rotainers) and
transported by truck to a transfer station near San Felipe, where its freighted
by railway to the Ventanas, Valparaíso or San Antonio ports.
Ongoing and outstanding tasks
The Company has also been progressing a number of other areas of the PFS.
With the environmental approval obtained in April 2020 and the corresponding
resolution issued this week, additional drilling can commence during the third
quarter of this year. The information from this drilling programme will be used to
update the geological and domain models and the Company expects to then be
able to generate an updated resource estimate.
Work to date has included operational pit design for the definition of PFS drilling,
push-back sequence strategy, waste dump strategy and preliminary design, and
definition of early earth movement and upper level access for the process plant
and infrastructure engineering.
With the results of the upcoming drilling, the Company expects to be able to finalize
an operational mine plan and prepare a reserve statement. As part of this process,
the drilling results will also be used to prepare an updated geotechnical
A program of additional composite preparation and testing is underway, as well as
the definition of further variability samples which are to be included in the testwork.
Pending work also includes selective molybdenum and copper flotation testing,
critical water content testing (Atterberg limits) and environmental characterization
of the tailings.
The main ongoing items include the trade-off studies for water procurement
infrastructure and preliminary engineering, and the design of the Rocín River
diversion intake and tunnel.
Approval of the environmental declaration (“DIA”) for PFS drilling has been
obtained. The work for the environmental impact assessment (“EIA”) for the
construction and operation of the Project is underway, including the identification
of environmentally sensitive areas to be avoided during project design, seasonal
environmental baseline work and the implementation of the river monitoring
stations for hydrology and water quality baseline studies. Further impact studies
and baseline work (air quality, paleontological, archeological, etc.) will be required
once the Project is further defined.
Social & Community Engagement
Meetings with community organizations and authorities to present the Project have
been taking place on an ongoing basis. The Company has implemented a program
of community engagement activities which has included funding educational and
other social programs. The recent environmental approval has included
commitments for social programs which are being implemented.
As the Project is further defined, the social baseline work needs to be updated and
expanded. A formal community consultation process has to be conducted as part
of the EIA preparation This process can only be carried out once the key elements
of the Project are determined.
Depending on how the COVID-19 situation develops, the Company expects the
Pre-Feasibility Study to be completed by the end of the first quarter in 2021.