Orocobre Completes Long-Term Pump Testing at the Cangrejillos/Salinas Grandes Potash-Lithium Project

Orocobre Completes Long-Term Pump Testing at the Cangrejillos/Salinas Grandes 
Potash-Lithium Project 
Highlights 
- Long-term pump testing completed on five test-production wells. 
- Pump testing shows that brine volumes can be extracted from wells
from the shallow potassium-lithium resource at a sufficient rate and
concentration to support modest potash and lithium production. 
- Brine grades stabilized during the pumping tests with some
variation in average grade between holes.  
- Test work since 2010 suggests the attractive brine chemistry; with
a low Mg/Li ratio, high K/Li ratio and low sulphate and calcium
levels; will result in high recoveries of potassium and lithium. 
- Internal studies are underway to develop the strategy for further
project advancement. 
BRISBANE, AUSTRALIA -- (Marketwired) -- 06/10/13 -- Orocobre Limited
(TSX:ORI)(ASX:ORE) (the Company or Orocobre) reports completion of
long-term pump tests at the 85% owned Salinas Grandes Potash-Lithium
project ("Salinas Grandes") in Salta Province, North West Argentina. 
Salinas Grandes has an inferred resource, to a depth of 13.3m,
estimated to contain 56.5 million cubic metres of brine at 795 mg/L
lithium and 9,550 mg/L potassium, which is equivalent to 239,200
tonnes of lithium carbonate and 1.03 million tonnes of potash
(potassium chloride) based on 5.32 tonnes of lithium carbonate being
equivalent to 1 tonne of lithium and 1.91 tonnes of potash being
equivalent to one tonne of potassium. 
To view Figure 1, please visit the following link:
http://media3.marketwire.com/docs/orl0610fig1.pdf. 
Following completion of the resource estimate in 2012 the company has
conducted long-term pump tests on five test production wells and two
trenches within the central area of the salar. The purpose of the
test work was: 


 
--  to ascertain whether a sufficiently high pumping rate could be achieved
    from the aquifer (being only to 13.3m depth) 
--  to investigate changes in permeability over the salar and to determine
    whether there are preferred areas for possible future extraction 
--  to ascertain whether the brine would maintain a stable grade during
    extraction and not be diluted by brackish water beneath the brine body

 
An extensive array of monitoring wells was established around test
production wells and trenches. These provided information on the
drawdown cones of wells and variations in brine chemistry with time. 
Drilling and Geology 
Orocobre previous drilled a total of 12 diamond drill holes in the
Salinas Grandes salar to an average depth of 71.4 metres, with
certain holes as deep as 180 metres and 47 shallow auger holes to a
typical depth of 12m. 
The shallow brine body is hosted in a sequence of silt and clay
units, with minor intercalated sand - which generally increase in
proportion towards the north of the salar. Halite extends to a
maximum thickness of 0.5 metres below surface in the center-south of
the salar. Drilling established there are higher permeability zones
within the salar, associated with intervals of higher sand content
and as channels within lower permeability silts and clays. 
Pump Testing Methodology 
To evaluate the potential for long term brine extraction from the
Salinas Grandes salar pump testing was completed on five
purpose-constructed test production wells. These wells were drilled
to between 12.5 and 13.5 m below surface, using a rotary drilling
rig, with the wells reamed to an outside diameter of 18 inches. Well
casing with a diameter of 12 or 8 inches was installed in the wells,
with the length of the casing perforated throughout. A clean well
sorted 1-2 mm sand pack was installed as a filter around the casing
in the holes. The location of the wells is shown in figure 2. 
To view Figure 2, please visit the following link:
http://media3.marketwire.com/docs/orl0610fig2.pdf. 
A network of monitoring wells was established at distances of 5, 10
and 15 metres from each pump well. Additional monitoring wells were
installed around the higher yielding hole CJB005, 50 and 100 metres
from this pump well. Monitoring was conducted using a Solinst down
hole water level dipper and using data loggers in the pump well and
surrounding wells. 
Wells were pump tested by installing submersible pumps near the base
of the five wells and monitoring changes in the standing water level
in the pump well and the surrounding monitoring well network over a
period of up to 91 days (in HCJ009HY). 
Pump Test Results 
Representative hydraulic conductivity (K) values calculated from the
long term pump tests are in the range of 0.3 to 8.9 m/day. These pump
test details are summarized in Table 1. These values are comparable
to the range of values from 0.3 to 52 m/day from 12 short term tests
in undertaken in 2011from the auger drilling programme. 
Table 1: Pump test results from the five long-term pump tests carried
out at Salinas Grandes 


 
----------------------------------------------------------------------------
Test                                       Screened Total  Pump         Pump
hole     Predominant                          depth Depth  rate Average time
number   lithology                                m     m   l/s  Km/day Days
----------------------------------------------------------------------------
CJB004   Clay with 0.2 m sand unit at 6 m      0-10  12.5  0.51     0.3   27
----------------------------------------------------------------------------
CJB005   Clay with fine sandy silt 9-11.5                                   
          m                                    0-10  12.5  2.71     8.9   88
----------------------------------------------------------------------------
HCJ009HY Clay with sand and sandy silt                                      
          3.2-5.8; 11.5-12                   0-11.5  12.5  1.55     1.1   91
----------------------------------------------------------------------------
HCJ028HY Clay with 0.15-0.6 m fine silty                                    
          sand                               0-11.4  12.5  1.62     0.9   55
----------------------------------------------------------------------------
HCJ033HY Clay with gypsiferous sand from                                    
          0.5-1.8 m                            0-13  13.5  0.61     0.4   61
----------------------------------------------------------------------------

 
Although pump production declined to less than 1 l/s in two wells the
remaining three wells sustained pump rates of between 1.55 and 2.71
l/s, with continuous pumping (interrupted for routine refueling of
generators and maintenance) over a period of up to 91 days, before
the test program was terminated. This suggested that wells are
capable of supporting long-term brine production, although there is
little available drawdown in most wells, with water levels close to
the depth at which the pumps were installed. For production pumping
this would probably require periods where wells are allowed to
recover, with pumping switched to other wells during the recovery
periods. 
The highest yielding well (CJB005) is located in the central eastern
part of the salar, with well HCJ028HY approx. 1.5 km to the NW. Well
HCJ009HY is located near the northern boundary of the salar. Overall
the pump tests show there is considerable variation in permeability
within the salar. 
Brine Chemistry 
Lithium and potassium concentrations declined during the initial 15
day period of the 2012 pump tests prior to stabilizing or showing
only minor declines in concentration (Figure 3 below). Overall
results suggest that relatively constant brine concentrations can be
produced from a well following this initial period of decline. The
initial decline in concentrations is interpreted to reflect depletion
of particularly concentrated brine from the surficial halite layer
and underlying surficial sand intervals, relative to long-term
contributions from silt, clay and minor sand units deeper within the
well. 
To view Figure 3, please visit the following link:
http://media3.marketwire.com/docs/orl0610fig3.pdf. 
Trenching Pump Test 
Two trenches were constructed in the north west of the salar, in the
area established by auger drilling to host Li values of greater than
800 mg/l. These were constructed with dimensions of 50 m by 3 m, and
1.5 m deep. The objective of this test program was to evaluate
whether trenches could be used to extract brine from the shallow
aquifer and to solar pre-concentrate the brine prior to extraction.
Samples of brine taken following trench construction showed Li values
exceeding 1700 mg/l. An evaluation of the economics of trench versus
pump well construction will be evaluated as part of the scoping
study. 
Data Collection and QA/QC 
Measurements of water levels and brine physical parameters (pH,
density, Eh, TDS, temperature) were made systematically throughout
the pump tests, with 272 primary samples collected for analysis.
Brine samples were sent to the Orocobre Olaroz project laboratory for
chemical analysis, including Li, K, B, Mg SO4 and Cl. 
Additional brine samples were sent for chemical analysis to the Alex
Stuart Assayers Mendoza, Argentina laboratory, which has been used by
the company since 2010. This laboratory has extensive experience
analyzing brines from salar projects. They are ISO 9001:2000
accredited and operate their own internal standards consistent with
ISO 17025. 
Four different laboratory prepared standards were used as part of the
Quality Assurance-Quality Control program, comprising 36 standard
samples. In addition 42 blank samples were submitted with primary
samples during the program. A total of 24 duplicate pairs were
analysed as part of the pump testing program. 
Analytical values generally fell within +/-10% of the standard values
for samples. Overall duplicate samples showed a reasonable level of
sample repeatability (precision). 
During pump testing the brine extracted from wells was pumped through
PVC pipes a distance greater than 300 metres from the pump well. The
brine was then released onto the salar surface and allowed to
evaporate, to minimize the possibility of infiltration and recharge
of the pump and monitoring wells. 
Management Commentary 
Orocobre's Managing Director, Richard Seville, stated: "The
completion of the long-term pump tests is an important milestone for
the Salinas Grandes project. The work completed at Salinas Grandes to
date confirms the potential that brine can be extracted from the
shallow resources at potentially commercial rates and with stable
grades that could allow for modest annual production of potassium and
lithium to augment our flagship Olaroz project, now under
construction. 
"The Salinas Grandes shallow brine body has attractive grades and
excellent chemistry, with a low magnesium to lithium ratio, high
potassium to lithium ratio and low sulphate levels, which should
result in high recoveries and low operating costs. To better
understand the potential for Salinas Grandes the company has
initiated an internal study which will set determine the strategy for
advancing the project further." 
About Orocobre Limited 
Orocobre Limited is listed on the Australian Securities Exchange and
Toronto Stock Exchange (ASX:ORE)(TSX:ORL) and is the leading
lithium-potash developer in the lithium and potassium rich Puna
region of Argentina. For further information, please visit
www.orocobre.com. 
Competent Person's and Qualified Person's Statement 
The technical information in this announcement has been prepared by
Murray Brooker. Murray Brooker is a geologist and hydrogeologist and
is a Member of the Australian Institute of Geoscientists. Murray has
sufficient relevant experience to qualify as a competent person as
defined in the 2004 edition of the Australasian Code for Reporting of
Exploration Results, Mineral Resources and Ore Reserves. He is also a
"Qualified Person" as defined by Canadian Securities Administrators'
National Instrument 43-101. Murray Brooker consents to the inclusion
in this announcement of this information in the form and context in
which it appears. 
Additional information relating to the Company's Salinas Grandes
project is available in the existing technical report entitled
"Technical Report - Salinas Grandes Project, Argentina" dated April
30, 2010, which was prepared by John Houston. 
Caution Regarding Forward-Looking Information 
This report contains "forward-looking information" within the meaning
of applicable securities legislation. Forward-looking information
contained in this report may include, but is not limited to, the
estimation and realization of resources at the Salinas Grandes
project, the viability, recoverability and processing of such
resources, potential operating synergies between the Salinas Grandes
project and the Olaroz project, and other matters related to the
development of the Salinas Grandes project. 
Such forward-looking information is subject to known and unknown
risks, uncertainties and other factors that may cause actual results
to be materially different from those expressed or implied by such
forward-looking information, including but not limited to the risk
that further funding may be required, but unavailable, for the
ongoing development of the Company's projects; changes in government
regulations, policies or legislation; fluctuations or decreases in
commodity prices; the possibility that required permits may not be
obtained; uncertainty in the estimation or economic viability of
mineral resources; general risks associated with the feasibility and
development of the Salinas Grandes project; unexpected capital or
operating cost increases; uncertainty of meeting anticipated program
milestones; as well as those factors disclosed in the Company's
Annual Information Form for the year ended June 30, 2012 filed at
www.sedar.com. 
The Company believes that the assumptions and expectations reflected
in such forward-looking information are reasonable. Assumptions have
been made regarding, among other things: the Company's ability to
carry on its exploration and development activities, the timely
receipt of required approvals, the prices of lithium and potash, the
ability of the Company to operate in a safe, efficient and effective
manner and the ability of the Company to obtain financing as and when
required and on reasonable terms. Readers are cautioned that the
foregoing list is not exhaustive of all factors and assumptions which
may have been used. 
There can be no assurance that forward-looking information will prove
to be accurate, as actual results and future events could differ
materially from those anticipated in such information. Accordingly,
readers should not place undue reliance on forward-looking
information. The Company does not undertake to update any
forward-looking information, except in accordance with applicable
securities laws. 
ABN 31 112 589 910
Contacts:
Australia and Asia: Orocobre Limited
David Hall
Business Development Manager
+61 7 3871 3985 or M: +61 407 845 052
dhall@orocobre.com 
North America: Orocobre Limited
James Calaway
Chairman
+1 (713) 818 1457
jcalaway@orocobre.com
www.orocobre.com
 
 
Press spacebar to pause and continue. Press esc to stop.