Home |  News |  Conferences |  Commodities |  Publications |  Business Directory |  Resources |  Help
Go to the MEI Online homepage

Search Site:

MEI Online: Plant Operation News: North America: June 28th 2012


click to find out about MEI Conferences


:: Ireland Inc. Completes Installation of New Gravity Circuit and Reports First Precious Metals Extraction


First 10,000 Pound Test Yields Encouraging Gold and Silver Metal Recovery

Ireland Inc. today reported it has recently completed the installation of the gravity concentration circuit at its Columbus Project in Esmeralda County, Nevada. The pilot plant is now capable of both producing and leaching concentrates from the sand material that is located in the northwest section of the Columbus Project Property.

Ireland also reports encouraging gold and silver metal extraction results from the first gravity concentrates produced by this new circuit. A gravity concentration test was completed on 10,821 pounds of sand material extracted from the North Sand Zone and processed through the new circuit. Concentrates produced by the extraction circuit resulted in precious metals recovery of 0.5467 ounces of gold (Au) and 0.8295 ounces of silver (Ag). This equates to a recovered head grade of 0.101 ounces per ton (opt) Au and 0.153 opt Ag.

Precious Metals Extraction Process Optimization

Ireland completed a bulk test of 10,821 lbs (5.411 tons) of sand material taken from the same area in the Columbus Project's North Sand Zone as the concentration tests previously reported in January and February 2012. The extracted materials were processed through Ireland’s onsite pilot plant, producing concentrates weighing 1,873.6 lbs, an approximately 5.8:1 concentration ratio. The concentrates were then sent to AuRIC Metallurgical Laboratories, LLC for leach testing, resin collection and precious metal recovery. The concentrates were leached using sodium thiosulphate and collected on resins for ashing. The net precious metals recovered from the ashed resins totalled 0.5467 oz (17.004 g) Au and 0.8295 oz (25.80g) Ag. This equates to a recovered head grade of 0.101 opt Au and 0.153 opt Ag based on precious metals recovered.

"Although this was the first bulk leach test of the concentrates produced from the onsite pilot plant, we believe this represents another significant achievement as it reflects positively on the gravity concentration components of our pilot plant,” said Douglas D.G. Birnie, Ireland’s Chief Executive Officer. “While we are pleased with these net extraction results, we will conduct additional offsite batch leach tests in the laboratory to confirm the precious metal extraction results before we scale up at the pilot plant to continuous onsite leaching, resin collection and precious metal extraction testing. We also continue to optimize the operating parameters of our onsite pilot plant."

Readers should note that the results released today are from a single bulk test and may not be representative of grades or recovery rates that can be expected for the overall project. This latest gravity concentration test was completed on material that is probably significantly higher in head grade than the overall average head grade of the North Sand Zone as determined by caustic fusion assays of hundreds of drill samples to a depth of 200 feet below the surface of the Columbus Basin. Based on these recent test results, Ireland makes no assumptions or assertions that the overall head grade of the North Sand Zone differs from the previously disclosed average of 0.038 opt AuE (0.034 opt Au, 0.179 opt Ag). While the most recent tests have shown greater recovery rates than 0.038 opt AuE, the area from which these samples were taken may represent an anomaly within the North Sand Zone and may not be representative of the entire zone. Additional gravity concentration tests on bulk samples from different sites within the North Sand Zone will follow.

Ireland continues to work on optimizing the precious metals extraction circuit at its Columbus Project. During earlier evaluation tests, limited quantities of gold and silver were produced, as previously disclosed. This new test represents the largest quantity of gold and silver extracted to date. If further batch testing continues to be successful, Ireland intends to progress to continuous processing and precious metals extraction at its onsite pilot plant at the Columbus Project.




Click for more info on Process Mineralogy '20

Select the list(s) you'd like to join below, enter your email address, choose a content format and click "Join."
[more info]

MEI Online Update
MEI Online Job Vacancies


© 1998-2017, Minerals Engineering International

Email: amanda@min-eng.com