Feb 20 2015
Ireland Inc. today provided a progress update on its new gold extraction process at the Columbus Project, located in Esmeralda County, Nevada. Testing of the new process was completed by Arrakis Inc. at its laboratory in Denver Colorado, and has increased gold extraction to +0.20 opt Au in batch tests (500g & 100g) of sands extracted from the North Sand Zone of the Columbus Project.
New Gold Extraction Process
The new gold extraction process was developed over the past year after scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD) and zeta potential tests identified the mineralogical character of the gold found in the sands located in the North Sand Zone and the metallurgical character of that gold after leaching. The new process, called “TPAC,” involves thermal pre-treatment (TP) of the sands, followed by autoclave leaching (AC). The TPAC process removes the refractory coatings from the gold sufficiently to allow, for the first time, the TPAC products to be assayed by standard fire assay. The fire assay results by Arrakis on samples processed using the TPAC method are as follows:
- Test 1: 500g head sand – 0.314 opt Au (TP and AC at Arrakis)
- Test 2: 100g head sand – 0.203 opt Au (TP at Columbus, AC at Arrakis)
- Weight Mean Average=0.296 opt Au; Average=0.259 opt Au
The samples were splits from a bulk sample taken at the S7A drill hole location in the North Sand Zone and then shipped to Arrakis for TPAC processing and assaying as indicated above. These tests also demonstrated that the gold is leachable by autoclaving (AC) after the temperature pre-treatment (TP).
These results have now caused Ireland to re-focus on the gold resources in the North and South sand zones by re-assaying the drill core samples from prior drill programs using the TPAC method. Ireland previously disclosed that the mineralized samples taken within the North and South sand zones had a weight mean average of 0.041 opt Au using a caustic fusion analytical method. Ireland expects to release the results from this re-assaying program as they become available. That first data is expected to be available before March 31, 2015, with all re-assaying work expected to be completed by June 30, 2015.
Concurrent with the re-assaying program, new concentration and leach methods will be tested for the pilot plant at the Columbus Project. This work will incorporate the new mineralogical and metallurgical data gained from developing the TPAC process into the pilot plant’s gold extraction circuit, to extract gold and to evaluate commercial viability at the Columbus Project. The final extraction costs of the TPAC treatment process have yet to be determined. Upon successful completion of these tests, the process will be scaled up in size to test larger volumes of material.
New Test Results Improve Gold Extraction
“Our goal has been to achieve commercial gold and silver extraction rates at the Columbus Project. These most recent results achieve markedly higher extractions (±0.26 opt Au) than earlier results,” stated Douglas D.G. Birnie, President of Ireland Inc.
“This TPAC process is the result of years of testing and analysis to understand the mineralogy of the Columbus Project,” continued Birnie. “The recent test work, which was completed over the past year, led us to develop, test and improve the TPAC process. I realize that our timelines and delays have been frustrating to us and to our investors. We are thrilled with these excellent recent extraction results and believe that this has been a significant breakthrough. We are encouraged and optimistic about the technical program at the Columbus Project.”
Prior to the TPAC method, no gold was extracted using standard fire assay techniques on samples extracted from the North Sand Zone due to the refractory nature of the minerals entombing the precious metals found in those sands. The TPAC process sufficiently removes these refractory coatings and allows, for the first time, extraction of gold by standard fire assaying as noted above. Readers should be cautioned that samples for the two reported tests were extracted from the same location, which was the same location as previously completed bulk sample tests. Reported results may not be representative of grades or recovery rates that can be expected for the rest of the North Sand Zone or the rest of the Columbus Project as a whole. Further, third party chain of custody protocols were not observed during these tests as Ireland staff assisted in sample collection and preparation.
A technical report with more details about these tests, including a process flow diagram, the next tests scheduled, and a summary of historical work done to date will be made available to the public. Ireland expects that its scheduled technical program for the next six months will cost approximately $2,000,000. Ireland will need to obtain additional financing in order to complete its planned technical program.
Source: http://irelandminerals.com/