Dec 4 2017
Orocobre Limited is pleased to provide an update on the brine sampling of diamond drill hole CAU16 in the previously undrilled NW Sector of the Cauchari JV property located in Jujuy Province, Argentina.
The exploration program is being managed by JV partner Advantage Lithium Corp. who hold 50% of Cauchari, earning up to 75%. Orocobre owns 35% of Advantage Lithium's issued capital.
Highlights:
- Systematic brine sampling is now complete in hole CAU16 which intersected permeable sandy sediments that are expected to yield relatively high pumping rates
- The brine body extends over >284 metres vertically starting at 14 metres and includes a 81 metre high grade interval from 118-199 metres, similar to CAU07, 3 kilomtres north
- The high grade brine interval averages 529 mg/l Lithium and 4,306 mg/l Potassium, including four samples averaging 619 mg/l Lithium from 169 to 199 metres
- The brine has a low Mg/Li ratio of 2.5:1, similar to CAU07 and the brine being processed at the Olaroz Lithium Facility making it suitable for the same processing route
- Diamond drill hole CAU15 (6.5 km south of CAU16) is currently at 205 metres and encountering intervals of sand in the hole similar to CAU16 and CAU07
- Pumping tests have commenced on wells installed in rotary holes CAU08 and CAU10
Managing Director and CEO, Richard Seville, commented, "We are very pleased with the results being generated by the drilling programs managed by JV partner, Advantage Lithium. The results from CAU16 confirm the continuation of the brine body south from CAU07 with good grades and good chemistry. The presence of sandy sediments throughout the hole is a very positive indicator for both porosity and potential flow rates and brine extraction. Drilling will continue in the SE and NW sectors into 2018 with three drill rigs now secured."
CAU16 Drilling Results
The average concentration over the sampled length of CAU16 (14 – 298 metres, total depth 321.5 metres) is 436 mg/l Lithium and 3,608 mg/l Potassium from 40 primary samples taken at systematic depth intervals.
Sampling delineated a high-grade brine interval averaging 529 mg/l Lithium and 4,306 mg/l Potassium over 81 metres (118 – 199 metres) within the larger brine body. Four brine samples within the previously reported 169 - 199 metre interval average 619 mg/l Lithium and are part of the 81 metre interval average of 529 mg/l Lithium.
The brine body defined to date continues from CAU07 in the north, through CAU16 and further south to hole CAU15, which is currently being drilled. This is a distance of over 12.5 km approximately north-south. These diamond core holes have all intersected relatively permeable sandy sediments that are expected to yield relatively high pumping rates from the NW Sector, which is very positive for future brine extraction.
Brine sampling was undertaken systematically at nominal six metre depth intervals using both bailer and packer sampling equipment, depending on the conditions encountered in the hole. The average concentration for the high-grade interval (118-199 metres) and average concentration over the entire length of CAU16 (to 298 metres) is based on both bailed and packer samples.
The Mg/Li ratio in all brine samples is consistently low, averaging 2.5:1 across all the samples, and 2.3:1 in the high-grade interval. The consistently low Mg/Li ratio confirms the suitability of the brine for conventional brine processing, as applied at the nearby Olaroz project.
Drill core samples from CAU07 and CAU16 have been sent to an experienced porosity laboratory in the United States, where they will be analysed for drainable porosity characteristics for use in the upcoming resource estimate.
SE Sector Drilling - CAU08 and CAU11 Progress
In the SE sector, well development and pump installations have been completed on rotary holes CAU08 and CAU11 in preparation for initial pumping tests and collection of composite brine samples.
Managing Director and CEO, Mr Richard Seville, also commented, "These results give us further confidence to continue exploration efforts in the very strategic NW sector, located immediately south of our Olaroz properties. The CAU16 results suggest the brine body on the NW side has the potential to be an important part of the overall resource base with the potential to support a stand-alone processing facility."
Source: https://www.allkem.co/