Cauchari hole CAU11 - pumping at 19l/s at 515 mg/l Lithium

BRISBANE, Australia, Feb. 6, 2018 /PRNewswire/ -- Orocobre Limited (ASX: ORE, TSX: ORL ) ("Orocobre" or "the Company") is pleased to provide an update on the brine sampling of diamond drill hole CAU11 in the Cauchari JV property located in Jujuy Province, Argentina.

The exploration program is being managed by JV partner Advantage Lithium Corp. ("Advantage Lithium") (TSX Venture: AAL) (OTCQX: AVLIF) who hold 50% of Cauchari, earning up to 75%.  Orocobre owns 33% of Advantage Lithium's issued capital.

Highlights:

• Brine flow rate of 19 litres per second (l/s) at 515 mg/l Lithium and 4,577 mg/l Potassium in hole CAU11 in the SE Sector, from a newly discovered deep sand unit

• Lithium concentration of 517 mg/l Lithium and 5,319 mg/l Potassium in hole CAU08 in the SE Sector

• The brine from CAU11 and CAU8 has low Mg/Li ratios averaging 2.6:1 and 2.4:1 respectively

• Rotary hole CAU07 was completed and will undergo pumping tests in February 2018

• Core holes CAU12 and CAU13 in the SE Sector have advanced to depths of 377 m and 439 m, respectively

SE Sector - CAU11 drilling results

CAU11 is located in the SE Sector of the property; 5.6 km southeast of CAU09. This drill hole intersected sediments comprising halite, clay and some sand to 405 m depth.  An important interval of sand dominated material was encountered from 405 m to 480 m depth and corresponds to a deeper sand unit which the company was exploring for. Further exploration will be undertaken to evaluate the extent and thickness of this sand dominated unit.

The initial constant rate pumping test conducted on hole CAU11 sustained a flow rate of 19 l/s over a period of 48 hours, which is promising for future brine production. This flow rate was at the upper limit of the pump capacity used for the test. A total of 18 brine samples were taken during the pumping test, with the average concentration of 515 mg/l Lithium and 4,577 mg/l Potassium and a Mg/Li ratio of 2.6:1.

SE Sector - CAU08 drilling results

CAU08 was drilled to a depth of 400 m in the south of the SE sector of the project, approximately 3.5 km south from CAU09 and 5 km south-southeast of CAU10. CAU08 intersected a sequence of clay, silt and some sand and halite, with significantly less halite intersected than in CAU09 and CAU10 further to the north. Drilling was not sufficiently deep to intersect the target sand dominated unit encountered in CAU11, due to the physical limitations of the drilling rig. Consequently it is not yet clear if the deeper sand unit extends this far north and east.

Screened and blank casing along with gravel pack were installed to the 400 m depth. The hole was subsequently cleaned and developed prior to the preliminary pumping test and brine sampling. A pumping test was carried out at a flow rate of 2 l/s over a 48 hour period.  A total of 34 brine samples were taken during the pumping test. Brine analyses averaged 517 mg/l Lithium and 5,319 mg/l Potassium, with the Mg/Li ratio at 2.4:1 very similar to the ratio in holes further north in the properties and to results in the producing Olaroz lithium project.

All brine analyses were completed in a commercially accredited laboratory in Argentina, accompanied by QA/QC samples, comprising brine standards and duplicates¹. This information confirms the importance of the sand dominated units that Advantage has been exploring for and encountered in CAU11 and which will be the focus of further exploration in the SE Sector. Confirmation of the deeper sand unit compliments the presence of extensive sandy material and similar brine grades in the NW Sector.

SE Sector – Additional drilling

Diamond holes CAU12 and CAU13 in the SE Sector are at depths of 377 m and 439 m respectively and have both encountered sandy material. Continuation of these holes will establish whether this is related to the sand unit encountered in CAU11. Brine assays results will be reported from these holes when they are received from the laboratory.

NW Sector – Additional drilling

Well CAU07 has now been completed to a final depth of 348m in the north of the NW Sector and will be cleaned and developed prior to undertaking a pumping test in February. Results of initial brine sample analyses were reported on 8 November 2017 with concentrations of 635 mg/l Lithium and 4,772 mg/l Potassium at a depth of 236 m.

The pre-collar for diamond hole CAU18 in the far north of the NW Sector is near completion. Drilling of the pre-collar for CAU17, also in the north of the NW Sector will be completed following CAU18.

For more information please contact:

Andrew Barber
Investor Relations Manager
T: +61 7 3871 3985                                                                                           
M: +61 418 783 701                         
E: [email protected]

Competent Persons Statement
The information in this report that relates to exploration reporting at the Cauchari JV project has been prepared by Mr Murray Brooker. Murray Brooker is a geologist and hydrogeologist and is a Member of the Australian Institute of Geoscientists. Mr Brooker is an employee of Hydrominex Geoscience Pty Ltd and is independent of Orocobre. Murray has sufficient relevant experience to qualify as a competent person as defined in the 2012 edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves. He is also a "Qualified Person" as defined in NI 43-101. Murray Brooker consents to the inclusion in this announcement of this information in the form and context in which it appears.

About Orocobre Limited
Orocobre Limited (Orocobre) is a dynamic global lithium carbonate supplier and an established producer of boron. Orocobre is dual listed on the Australia and Toronto Stock Exchanges (ASX: ORE), (TSE: ORL). Orocobre's operations include its Olaroz Lithium Facility in Northern Argentina, Borax Argentina, an established Argentine boron minerals and refined chemicals producer and a 35% interest in Advantage Lithium.

For further information, please visit www.orocobre.com  

¹ Assaying completed at Alex Stewart Laboratories in Jujuy city, Argentina under strict QA/QC protocols.

SOURCE Orocobre Limited

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