Shares in West Perth-based Bass Metals have risen slightly in early trade after the company commissioned a metallurgical consultancy to undertake a scoping study at its Hellyer Tails resource in Tasmania.
Shares in West Perth-based Bass Metals have risen slightly today after the company commissioned a metallurgical consultancy to undertake a scoping study at its Hellyer Tails resource in Tasmania.
BatteryLimits and Como Engineers have been appointed to under take the study on the processing option for the economic recovery of gold, silver and possibly base metals from the project.
Bass Metals said the resource contains 0.8 million ounces of gold and 32 million ounces of silver.
In a statement Bass Metals said, "The results are preliminary in nature but do demonstrate potential for a viable new operational component at Hellyer to recover precious metals."
At the close of trade Bass Metals was up 5.26 per cent or 1 cent to 20 cents.
See company statement below:
Bass Metals Ltd (ASX:BSM) commissioned metallurgical consultancy, BatteryLimits Pty Ltd and Como Engineers Pty Ltd to undertake a scoping study on the processing options for the economic recovery of gold, silver and possibly base metals from the Hellyer Tails resource.
The resource contains 0.8 million ounces of gold and 32 million ounces of silver, with the gold being highly refractory associated with sulphide minerals and hence specialized recovery processes.
BatteryLimits has provided a metallurgical review, process descriptions, process schematics, and process design criteria for each of the three short-listed process routes.
Como Engineers has estimated capital and operating costs for each option.
Gold Processing Scoping Study Findings
The process routes identified following an assessment of the historical testwork and feasibility studies were:
1. Direct Cyanide Leach with Cyanide Recycling - Option 1.
This involves attritioning, followed by cyanidation in a high cyanide environment with cyanide recovery (SART) and recycling before a gold and silver recovery phase to a dorè.
2. Fine Grinding with Oxidation (Albion Process) and Cyanide Leach - Option 2.
This involves flotation recovery to a bulk sulphide concentrate which would be fed to an
IsaMill and subjected to fine grinding before being leached at atmospheric pressure and 90-100oC, using Xstrata's Albion Process. The oxidised residue would be then fed to standard cyanidation circuit with gold and silver recovery to dorè. The Albion Process is marketed globally by Core Resources and has been previously tested using Hellyer tailings (Xstrata, 1999).
3. Partial Pressure Oxidative Leach - Option 3
A bulk flotation concentrate is finely ground and fed into an autoclave for oxidation. Testwork indicates that optimum recoveries are achieved at partial oxidation of the sulphides reducing the autoclave residence time and hence the capital costs. Base metals will dissolve and report to the autoclave leach solution where zinc and copper could be recovered as a saleable intermediate product. The gold and silver remain in the partially oxidised residue and are recovered by standard cyanidation and elution techniques as in Option 2 above.
