Bryah Resources Limited (ASX: BYH) has announced significant gold recovery from the leaching testwork undertaken on samples from the Windalah Gold Prospect located within its Bryah Basin Project in central Western Australia.
The company reported an average of 94% gold recovery from cyanide leaching testwork of 15 samples from hole BBRC049.
The hole BBRC049 had recorded high-grade gold interval of 12 metres @ 5.13 g/t Au from surface, including 2 metres @ 21.48 g/t Au from 3 metres in latest testwork.
BYH said that total gold assay results correlate well with initial laboratory analysis, and the results from follow-up gold drilling program are expected this week.
Bryah Basin project
The Bryah Basin project is located approximately 100-150km north of the town of Meekatharra in central Western Australia.
Significant prospects of the 1,135 km2 Bryah Basin Project include the Forrest gold, Brumby Creek, Black Hill, Cheval, Black Beauty, Windalah, Wodger, and Labouchere prospect.
OMM presently holds a 10% Joint Venture interest with Bryah retaining a 90% Joint Venture Interest in manganese and 100% in respect to all remaining minerals on the tenements.
Drilling at Windalah
The company had recently reported the Reverse Circulation (RC) drilling results from 3 drill holes BBRC047, BBRC048, and BBRC049 at Windalah.
The drill hole BBRC049 had reported the best gold interval of 12 metres @ 4.32 g/t Au from surface, including 2 metres @ 17.19 g/t Au from 3 metres.
Bryah has recently completed further drilling at Windalah with the results of seven holes (BBRC052-57 and BBRC060) due to be received later this week.
Leaching testwork
The company announced that to confirm this result from RC hole BBRC049, residual drill samples were delivered for testing for gold recovery by cyanide using a 6-hour bottle roll leach test at a laboratory in Perth.
Total of 15 samples
BYH reported that a total of 15 residual drill samples from BBRC049 were tested for gold recovery by cyanide using a 6-hour bottle roll leach test at Intertek Australasia’s laboratory in Perth.
The company said that the sample bags containing all the residual RC sample from the drilled metres were recovered from site and delivered to Intertek for analysis by their LeachWELLTM technique.
The full bags, weighing about 20 kg each, were crushed and split to produce a 1,000-gram sample for testing.
It may be noted that high-grade cyanide leaching utilises the LeachWELLTM accelerant to determine the cyanide extractable gold and provides an indication of potential recoveries in metallurgical processes and circuits. Recovery and analysis of the residues (tailings) allows reporting of total gold values.
The results of the LeachWELLTM and the tailings gold assay are added together for the total gold grade.
Average leaching recoveries of 94%
The company announced that the leaching recoveries ranged from 85% to 96%. BYH said that overall, the average across the 15 samples is 94% recovery.
BYH said that this is a very positive result, demonstrating the potential gold recoveries from Windalah using conventional cyanide leaching.
Overall grade of gold mineralisation increased
The company announced that the results from this testwork confirmed and increased the overall grade of the gold mineralised interval in BBRC049 (using a 0.5 g/t Au cut-off grade) to 12 metres @ 5.13 g/t Au from surface, including 2 metres @ 21.48 g/t from 3 metres
The results of the LeachWELL TM and the tailings gold assay, as well as the grade received from the initial RC sample analysis, undertaken using a 50-gram Fire Assay (FA50) method are listed below.
The company noted that the correlation check of the LeachWELL TM tests with the original FA50 results show a greater variance within the higher gold grades; up to +6.52 g/t Au higher in the case of BBRC049 (3-4m). Byrah said that this is likely to be a result of coarse gold causing nuggety effects.
Next steps
The company said that whilst these testwork results provide positive information in respect to gold recovery from conventional cyanide leaching, further definitive testwork will be required as this project is progressed towards development.
Bryah said that it has completed further drilling at Windalah and the results of seven holes (BBRC052-57 and BBRC060) is expected to be received later this week.
Management comments
Bryah Resources Managing Director, Neil Marston said: “We are delighted with these test results. These results confirm and increase the high-grade gold interval which was reported previously for hole BBRC049. Overall, the mineralised zone is 12 metres at 5.13 g/t gold from surface in this drill hole.
A very high-grade interval within this gold mineralised zone, which we originally reported as 2 metres @ 17.19 g/t gold from 3 metres, using conventional fire assay techniques, has reported an even higher grade of 2 metres @ 21.48 g/t gold from this bulk leaching testwork.
These results support our view that the gold from Windalah will be amenable to processing using conventional cyanide leaching techniques.
We have completed a follow-up drilling program at Windalah last month and expect to receive the assay results for seven new drill holes from the laboratory later this week.”