New Talisman Gold Mines (ASX: NTL) has managed to recover 94% and 93.6% gold without chemicals during metallurgical test work on ore from the Dubbo and Mystery zones at its Talisman project in New Zealand’s Hauraki goldfield.
According to New Talisman, the Mystery gold vein was recently discovered and a potential contributor to the mine.
Test work on the ore yielded a 94% gold recovery on Dubbo ore after mining and crushing, grinding, gravity concentration and flotation. The same process extracted 9.36% gold from Mystery ore.
“The completion of this test work demonstrates the successful ability to extract high grade concentrate from the existing ore bodies without the use of hazardous chemicals,” New Talisman chief executive officer Matthew Hill said.
“From a processing perspective, this is about as clean and environmentally friendly for treatment of gold ore as it gets with natural rock being reused as backfill,” Mr Hill added.
He said the test results were a “key milestone” for the company and enabled it to develop a saleable product without assistance from external parties.
Testing produced similar recovery rates to those obtained by using cyanide leaching.
The company will incorporate these latest results into its pilot plant design, which will be planned to be modular and scalable to accommodate production increases.
New Talisman has developed a resource at Talisman of more than 469,000 ounces of contained gold equivalent.
The average gold grade is higher than 15g/t.
Additionally, drilling across the project has returned numerous high-grade intersections including a notable 1.8m grading 656g/t gold and 2,080g/t silver.
New Talisman is refurbishing the historic underground mine at the project, with the company’s crew undertaking remedial works to depths of 600m and further.
The Talisman mining permit includes historical mines with more than 1 million ounces of gold and 3moz of silver intermittently produced across the permitted area between 1875 and 1992.
Shares in New Talisman had risen more than 23% A$0.016 by late afternoon trade.