Orocobre Limited - Cauchari Drilling Update

Orocobre Limited
2018-10-18 13:17 637

BRISBANE, Australia, Oct. 18, 2018 /PRNewswire/ -- Orocobre Limited (ASX: ORE, TSX: ORL) ("Orocobre" or "the Company") is pleased to provide this update on the brine sampling of diamond core hole CAU22 in the SE Sector of 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 75% of Cauchari. Orocobre owns 33.5% of Advantage Lithium's issued capital and 25% directly in the joint venture.


  • Systematic brine sampling completed in CAU22 averaged 549 mg/l lithium and 3,630 mg/l potassium from 146.5 – 290.5 m depth, with samples not yet received below this depth. The brine shows a similar grade and very low average Mg/Li ratio of 2.4:1, similar to that demonstrated during pumping of CAU11 – excellent for conventional brine processing
  • Results from CAU22, together with recently acquired TEM electrical geophysics in this area, confirm the extension of brine mineralisation in the SE sector to the fault forming the eastern boundary of the Cauchari basin
  • The Phase III infill drilling is the resource conversion program that aims to convert Inferred to Measured and Indicated resources by early 2019, with drilling on track for this timing
  • Drilling of holes CAU25 and CAU26 will further define the eastern extent of the SE sector, with the aim of adding to the existing resource
  • Drilling encountered interbedded units of clay, halite and sand in this area, a combination of lithologies which are known to be productive in other parts of the Cauchari-Olaroz basin
  • Pumping test equipment has been installed for the 30 day pump tests in CAU11 and CAU07, with pumping underway in CAU11.

Orocobre Managing Director Mr Richard Seville commented "Continuing excellent results from CAU22 highlight the understanding of the Cauchari basin and the likelihood the JV can grow the resource base. The Phase III systematic drilling and sampling program has confirmed the extension of mineralised brine below the 300 m depth of the existing resource in the east of the SE Sector, with geophysics suggesting the brine mineralisation extends further east than in the current resource. The Mg/Li continues to be low in this area, with positive brine chemistry. With four drilling rigs operating, the JV is on schedule with the resource conversion program that aims to upgrade the resource to Measured and Indicated status. Additionally extended pumping tests in test wells CAU07 and CAU11 are commencing, which will give us important hydraulic characteristics to complete the dynamic model for potential reserves."

CAU22 SE Sector Drilling Results

CAU22 is the first resource hole drilled along the eastern side of the SE Sector. The brine analyses confirm the high quality of the brine in this area averaging 549 mg/l lithium and 3,630 mg/l potassium from 146.5 – 290.5 m depth, with consistent results throughout the hole and a maximum value of 647 mg/l Li. A total of eight primary brine samples were taken with a bailer device and the result of one duplicate sample confirms the value of the primary sample. Samples were taken at nominal systematic 12 m intervals, considered an appropriate sampling interval, given the relatively thick and consistent lithologies encountered. QA/QC results are awaited from the secondary laboratory.

The brine samples have a very low average Mg/Li ratio of 2.4:1, similar to test production well CAU11. Results are similar to those of the adjacent Olaroz project of Orocobre and Lithium Americas Corp and Ganfeng in Cauchari. Similarity of brine characteristics across these properties confirms the Cauchari-Olaroz brine is very extensive and relatively homogeneous and suitable for conventional processing.

NW Sector Drilling Update

Drilling is continuing in the NW Sector with hole CAU28 underway. This hole is located 2.5 km south of CAU24, which is the southern-most hole drilled in the NW Sector. The results of CAU24 are awaited from the laboratory. Holes CAU28 and CAU29 are planned with the aim of extending the brine resource further south where high permeability sands and gravels are likely to exist relatively close to surface. Results will be released as they become available.

SE Sector Drilling Update

Further drilling is underway in the SE Sector in Hole CAU19, which aims to define the continuation of the deep sand unit from previously drilled holes CAU11, CAU12 and CAU13.

Pumping Tests

Preparations have been completed to carry out 30 day pumping tests on test production well CAU11 in the SE Sector and CAU07 in the NW Sector. All monitoring wells and equipment are installed. The first pumping test on CAU11 commenced on October 14 and will be followed immediately by CAU07.

The tests will provide additional information on aquifer characteristics as an input to the three-dimensional groundwater model that is being developed to estimate lithium reserves and to develop a production schedule for the project.

For more information please contact:

Andrew Barber
Investor Relations Manager                                                                              
Orocobre Limited                                                                                                                              
T: +61 7 3871 3985                                                                                            
M:+61 418 783 701                                                                                                           

Qualified Person's/Competent Person's 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 33.5% interest in Advantage Lithium.

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Source: Orocobre Limited
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Keywords: Mining Mining/Metals