3D Resources Limited has announced metallurgical test results and provided an update on progress for the Adelong Goldfield.
In May 2020, 3D Resources took control of the Adelong Gold Project which covers 70 square kilometres and comprises the old Adelong Goldfield.
The Adelong Goldfield is situated in Southern New South Wales, approximately 20 kilometres from Tumut and 80 kilometres from Gundagai.
The company had been investigating options for gold recovery in a pre-concentration stage for the Adelong Goldfield ores using gravity techniques at a coarse grind size of 80 per cent passing 300 and 1000 microns.
3D Resources notes that the test results to date have shown some very positive results that would indicate that this approach will recover the vast majority of the gold and can also generate a high-grade concentrate.
As part of the program two tests have been completed to date, with further testing underway to prove the initial gravity stage of the planned upgraded plant at Adelong:
1) A 60kg sample of ore was taken from the Run of Mine Stockpiles extracted from the 1380mRL level in the Challenger underground mine, and was tested at laboratories in Perth using techniques designed to emulate the Falcon Continuous Concentrator.
This test was run at 80 per cent passing 300µ on higher-grade ores from the Challenger underground mine. This test generated the following results:
Image credit: 3D Resources Limited.
The results (Table 1) highlight that 70 per cent of the gold can be recovered directly to a saleable concentrate of 45 grams per tonne (g/t) of gold (Au) (Con 1 and 2) and 87.5 per cent of the gold have reported to Con 1-5 (15 per cent Mass pull) with a grade of 24.1g/t Au.
3D Resources states that this clearly shows that the gravity system can be used as a low-cost process for recovering a major portion of the gold. These concentrates can then be upgraded, smelted or sold.
2) An approximately 1,000kg sample of lower grade ore was drawn from the run of mine stockpiles at the Adelong plant site.
This ore had been mined from a lower grade part of the 1380mRL level of the Challenger underground mine. The sample was shipped to Mineral Technologies in Brisbane to test the performance of spirals on the Adelong Goldfield ores.
The company noted that it has received the first test results based on an initial coarse grind to 80 per cent passing 1mm (1000µ).
Further tests are scheduled to be carried out using spirals including:
- Upgrading of the concentrates from this initial -1mm spiral test to a saleable concentrate using “cleaner spirals” (or more likely using shaking tables to emulate a cleaner spiral); and
- Reprocessing the “tailings” from the first spiral test after these tailings are reground down to 80 per cent passing 350µ with a similar set of spiral tests applied to the stage 1 test.
Exploration Program
The company is also progressing with plans for more than 2,000 metres of drilling as part of a phase two exploration program at the Adelong Goldfield.
The program, which is expected to be completed by the end of Q1 2021, aims to target extensions to resources that were outlined in the resource reports previously released (see 3D Resource’s ASX announcement 17 August 2020).
Additional drilling has also been planned at Challenger where there is potential for a parallel vein structure that could add to resources as well as a possibility of a southern extension to this deposit.
Phase two of the exploration plans to include:
- Completion of additional drilling on targets generated from the Maiden Resource estimation at Donkey Hill, Caledonian and Currajong East to upgrade those resources;
- Targeting of additional areas of mineralisation that have been identified by historic drilling that could add to future resource assessments or discoveries of new deposits;
- Completion of additional geophysics over areas where detailed interpretation is required to properly target drilling and better assess resources;
- Undertaking geochemical sampling over approximately 2 square kilometres to generate further drill targets; and
- Completion of geophysical and geological interpretation to target structures with potential mineralisation that have not been drilled previously.
The program depicted in Figure 1 includes the more than 3,000 metres of Reverse Circulation drilling that is planned.
The company outlines that further land access agreements to the Sawpit deposit and some of the potential to the north will be followed up once border restrictions into NSW are removed.
The full announcement can be found here.
