Commencement of Copper Recovery Trials
Kapunda Copper ISR Project, South Australia
The directors of Thor Mining Plc (“Thor”) (AIM, ASX: THR, OTCQB: THORF) are pleased to advise that a tracer test and in-situ lixiviant trials have commenced at the Kapunda Copper ISR Project in South Australia.
EnviroCopper Ltd (“EnviroCopper” or “ECL”), in which Thor holds a 30% equity interest, has completed the installation of test well arrays and has commenced in-situ recovery trials (“ISR”), including tracer and push pull test work. These tests are the final hydrometallurgical assessments before ECL commences Site Environmental Lixiviant Trials (SELT).
The purpose of lixiviant trials, or ‘push pull tests’, is to assess the solubility of copper mineralisation, and therefore copper recovery, using a specially designed solution called a lixiviant under in-situ conditions. The trial is to be undertaken in two stages. The first stage involves injecting and extracting a tracer solution (Sodium Bromide – NaBr) from the same well to demonstrate hydraulic connectivity between wells and the environmental monitor well network. This is followed by injecting and extracting lixiviant from the same well to test copper solubility from the mineralisation.
The trials are anticipated to take three to four weeks.
Nicole Galloway Warland, Managing Director of Thor Mining, commented:
“These in-situ lixiviant trials are a critical step in the assessment of the ISR process in determining the copper solubility hence recovery from the Kapunda copper mineralisation.
This is a significant milestone for the Kapunda ISR Project, which Thor is delighted to be a part of.
I would also like to congratulate and acknowledge the efforts of the ECL team on winning this year’s award for Innovation and Collaboration in the Resources Sector by the Department of Energy and Mining, South Australia for the Kapunda Copper ISR Project.”
https://www.energymining.sa.gov.au/premiers_awards_in_energy_and_mining
About Kapunda and EnviroCopper
The Kapunda ISR Copper Project is located approximately 90 kilometres north north-east of Adelaide in South Australia (Figure 1).
Thor holds a 30% interest in EnviroCopper, which in turn holds rights to earn up to a 75% interest in the mineral rights over metals which may be recovered via ISR contained in the Kapunda deposit from Australian listed company, Terramin Australia Limited (“Terramin” ASX:TZN) (AIM:THR Announcement 11 November 2020).
For detail of the ISR process, investors are invited to view the EnviroCopper website:
https://www.envirocopper.com.au/
Figure 1: The Tenement & Prospect Location Plan may be viewed by the following link:
https://www.thormining.com/sites/thormining/media/maps/17-007-1b-kapunda-alford-location.jpg
Lixiviant Trials – Push Pull Test
The purpose of lixiviant trials is to test the solubility of copper mineralisation using a lixiviant under in-situ conditions. The trial involves injecting and extracting tracer and/or lixiviant from the same well. Details of tasks/stages are as follows:
1. The installation of test well array and well house, which is now completed (Figure 2 and 3):
o One push-pull well screened across mineralisation
o Two observation wells – oriented along main line of lithology/structure
o Compliance monitoring wells located down gradient – nominally 25 to 50m from push pull well, screened across the same interval as injection and extraction wells
2. Well connectivity ‘tracer’ test using sodium bromide (NaBr). The tracer test is designed to demonstrate hydraulically the connectivity between the tracer test well and the observation and monitoring wells. The tracer test has commenced, with monitoring every 2 hours and is anticipated to be completed within 24-48 hours.
3. A lixiviant injection and extraction ‘push pull’ test including the installation of a well house (Figure 3). This is designed to test the solubility of copper in lixiviant under in-situ conditions.
o Drain lixiviant to injection well under gravity. Maintain water level in well at least 2m below ground surface
o Allow lixiviant to react with rock. 12 hourly samples for pH and copper.
o Reaction is complete when parameters are stable. Estimated to take up to 14 days.
4. Well rehabilitation. Restore Groundwater to baseline conditions
o Extract lixiviant from well until water quality returns to baseline conditions. Water is disposed of offsite at an approved EPA facility.
Key outcomes anticipated from lixiviant trials:
1. Hydraulic connectivity between wells
2. Copper solubility and recovery
3. Establish lixiviant and time parameters for design of the Site Environmental Lixiviant Trials (SELT).
The trials are anticipated to take three to four weeks to complete.
Figure 2: Lixiviant Push Pull Layout may be viewed by the following link:
https://www.thormining.com/sites/thormining/media/maps/push-pull-layout.png
Figure 3: Photos of well house may be viewed by the following link:
https://www.thormining.com/sites/thormining/media/maps/wellhouse.jpg
Next Step
Based on the results of the lixiviant trials, the Site Environmental Lixiviant Trials will be designed and permitted.
A scoping study is currently underway for the Kapunda ISR project including the optimal copper processing options and saleable copper product.
This announcement is authorised for release to the market by the Board of Directors.
– Ends –
For further information on the Company, please visit www.thormining.com or contact the following:
Thor Mining PLC
Nicole Galloway Warland, Managing Director
Ray Ridge, CFO / Company Secretary
Tel: +61 (8) 7324 1935
Tel: +61 (8) 7324 1935
