Big Sandy Lithium Project
About Big Sandy
Hawkstone Mining Limited (ASX: HWK) is an Australian Securities Exchange (ASX) listed Company focussed on the exploration and development of its 100% owned flagship ‘Big Sandy’ lithium project, located in Arizona, in the United States Battery Corridor.
Big Sandy is characterised largely by flat-lying basin sediments comprising predominantly of analcime and potassic alteration zones. The green lacustrine lithium bearing horizon is traceable for over 11km from north to south and extends at least 2km to the east as a flat sheet at or near surface.
Tenement map of the flagship Big Sandy lithium project
In February 2019, the Company commenced a fully funded 37-hole diamond drilling program on the Big Sandy project, which has produced exceptional results and high grade intercepts with a peak lithium value of 4,380ppm to date.
Maiden Mineral Resource
On 26 September 2019, the Company announced a Maiden Mineral Resources at the Big Sandy Lithium project, which was estimated by Cube Consulting, in accordance with the guidelines set out by the JORC Code (2012).
The Total Indicated and Inferred Resources were for a total 32.5 Million Tonnes (Mt) grading 1,850 parts per million (ppm) Li or 320,800 tonnes Lithium Carbonate Equivalent (LCE), reported above an 800 ppm Li cut-off. The Resource also included a higher-grade zone of 12.7 Mt grading 2,360 ppm Li above a cut-off of 2,000 ppm Li for 159,500 tonnes LCE, representing 49% of the total contained LCE.
Table 1 – Big Sandy Project Mineral Resource Statement (above 800 ppm Li cut-off)
Table 2 – Big Sandy Project Mineral Resource Statement (above 2,000 ppm Li cut-off)
Big Sandy Lithium Project Maiden Mineral Resource
The Maiden Mineral Resource was delivered 14 months after first drilling commenced at Big Sandy, in line with the Company’s rapid de-risking strategy. Significant potential tofurther expand the size of the Mineral Resource exists, with further drilling planned targeting Blocks B and C in the Northern Mineralised Zone (Figure 1), which remains open to the north, south and west. It should also be noted that the area drilled for the calculation of the maiden Resource represents a mere 4% of the landholding at the Big Sandy Lithium project.
This estimate follows the successful completion of the Phase 2 diamond drilling program (37 HQ diamond holes totalling 2,881m), focused on Block A. Please see the below part of this page for drilling results from the best intercepts.
Project Geology with Current and Planned Drill Hole Locations
The best intercepts to date include:
- 54.0m @ 2,041 ppm Li from 10.0m to 64.0m
- 34.0m @ 1,941 ppm Li from 32.0m to 66.0m
- 36.0m @ 1,892 ppm Li from 31.0m to 67.0m
- 44.0m @ 2,040 ppm Li from 12.0m to 56.0m
- 52.0m @ 1,953 ppm Li from 11.0m to 63.0m
- 47.0m @ 2,130 ppm Li from 12.0m to 59.0m
Diamond drilling on site at the Big Sandy project (May 2019)
Hawkstone Managing Director, Paul Lloyd, on site at the Big Sandy project during the 37 hole diamond drill program
The diamond drill rig used at the Big Sandy 37 hole diamond drill program
Project Location & Strategic Relevance
The Big Sandy lithium project is located on interstate I93 between Phoenix and Las Vegas, comprising of 331 Bureau of Land Management (BLM) claims in Arizona, covering approximately 25km².
The development of lithium projects is a priority for Federal U.S. agencies following the signing of the Executive Order ‘Federal Strategy to Ensure Secure and Reliable Supplies of Critical Minerals’ on 20 December 2017. Big Sandy is of strategic relevance, given the Tesla Gigafactory is located approximately 960km by sealed interstate highway to the north-west.
Project map showing the location of the Big Sandy Lithium project
Metallurgical Test Work
On 29 November 2019, Hawkstone Mining announced the results of the preliminary metallurgical test work, completed on a limited number of core samples from the Big Sandy lithium project, located in Arizona, USA. The testing program followed a successful maiden drill program and was purely designed as proof of concept that lithium could be extracted from the Big Sandy fresh material through the use of sulphuric acid as a metallurgical process.
The preliminary test work program proved highly successful, as samples recorded lithium recoveries of between 85% to 97%, during a maximum leaching time period of 24 hours. Following the success of this initial program, the Company will continue to further optimise the results on a wider range of samples, with the aim of reducing acid consumption and leaching time.
Leach test results, ambient temperature minus 1.7mm materials
Diagram showing a traditional lithium extraction process
