82.7% Au recovery rate in a 73 day leach cycle
Vancouver, BC - Northern Vertex Mining Corp. (the "Company") (TSX.V: NEE) is pleased to provide the metallurgical results obtained from heap leach cyanidation (column leach) testwork on a mineralized material low grade bulk sample from the Moss Mine Gold-Silver project located in Mohave County, Arizona, USA with highlights as follows:
- Lower grade mineralized material was readily amenable to agglomeration - heap leach cyanidation treatment at the 95% -1/4" crush size with respect to Au recovery
- Gold recovery rate was more rapid for the lower grade mineralized material vs. the higher grade mineralized material (previously reported in the Amended Preliminary Economic Assessment dated June 18, 2013)
- The column leach test recoveries were 82.7% for Au and 36% for Ag
- Lower NaCN consumption was observed for the low grade mineralized material vs. high grade mineralized material
- A relatively low cement addition (4 lb/ton ore) was required for agglomeration pretreatment of the low grade mineralized material
McClelland Laboratories, Inc., Sparks, Nevada, specialists in heap leach processing, have completed metallurgical test work on the low grade mineralized material from the Moss Mine Gold-Silver Project. The primary focus was to determine if there was a relationship between grade and recovery for the higher grade mineralized material and the lower grade mineralized material.
Metallurgical lab test results indicate that lower grade mineralized material was readily amenable to agglomeration - heap leach cyanidation treatment at the 95% -1/4" crush size with respect to Au recovery. The sample tested was a bulk sample of mineralized rock, characteristic of the lower grade material that is expected during Pilot Plant Operations. The sample was prepared using a jaw/cone crusher circuit to 95%-3/4". The crushed material was then passed twice through a modified rolls crusher located in Phoenix, Arizona.
The low grade material can be leached for shorter leach times compared to the high grade material, as indicated in the Amended Preliminary Economic Assessment dated June 18, 2013. Column test gold recoveries at a 73 day leach time on the low grade material, processed 2 x thru rolls, 95%-¼" inch were 82.7% for gold and 36% for silver whereas recoveries at a 112 day leach time on the high grade material, processed 2 x thru rolls, 95%-¼ inch were 84.6% for gold and 76.6% for silver.
NaCN consumption was lower for the low grade mineralized material vs. the high grade mineralized material. As well, a relatively low quantity of cement (4 lb/ton ore) was added during agglomeration pre-treatment. Leached agglomerates were not significantly degraded during leaching and remained strong and stable. Geotechnical characterization ("load/permeability" type testing) will be required to confirm permeability of the agglomerates under planned commercial heap stack heights.
Gold and silver leach rates profiles are outlined in the chart below:
Note: "HG" = High grade and "LG" = Low Grade
Qualified Person:
The foregoing technical information contained in this news release has been approved by Mr. Jack McPartland, B Sc., M Sc., Metallurgist / VP Operations, McClelland Laboratories, Inc., a Qualified Person ("QP") for the purpose of National Instrument 43-101 (Disclosure Standards for Mineral Projects).
Ownership:
Northern Vertex has the right to earn a 70% interest in the Moss Gold-Silver Property located in Mohave County, Arizona from Patriot Gold Corp. Subsequent to the Northern Vertex earn-in, financing of the project will be on a 70:30 proportional basis. The Company paid $500,000 in an upfront cash payment, and that, along with an $8 million work expenditure requirement and the preparation of a feasibility study (as defined in the earn-in agreement) are conditions of the 70% earn-in.
About Northern Vertex:
Northern Vertex Mining Corp. is a Canadian based exploration and mining company focused on the reactivation of the Moss Mine Gold-Silver Project located in NW Arizona, USA. The Moss gold-Silver Project is an epithermal, low sulphidation quartz-calcite vein and stockwork system which extends over a strike length of 1,400 meters and has been drill tested to depths of 200 meters vertically. It is a potential heap leach, open pit project being advanced under a three phase business plan, specifically designed to ensure that technical, economic, permitting and funding requirements are met prior to each phase proceeding. The Company's management comprises an experienced management team with a strong background in all aspects of acquisition, exploration, development, operations and financing of mining projects worldwide. The Company is focused on working effectively and respectfully with our stakeholders in the vicinity of the historical Moss Mine and enhancing the capacity of the local communities in the area.
ON BEHALF OF THE BOARD OF DIRECTORS
J.R.H. (Dick) Whittington, President & CEO
For further information, please visit www.northernvertex.com
or contact Investor Relations at: 604-601-3656 or 1-855-633-8798
Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.
Cautionary Note About Forward Looking Information
This news release contains statements about our future business and planned activities. These are "forward-looking" because we have used what we know and expect today to make a statement about the future. Forward-looking statements including but are not limited to comments regarding the timing and content of upcoming work and analysis, including the completion of a feasibility study. Forward-looking statements usually include words such as may, intend, plan, expect, anticipate, believe or other similar words. We believe the expectations reflected in these forward-looking statements are reasonable. However, actual events and results could be substantially different because of the risks and uncertainties associated with our business or events that happen after the date of this news release. You should not place undue reliance on forward-looking statements. As a general policy, we do not update forward-looking statements except as required by securities laws and regulation.
Cautionary Note to U.S. Investors:
This news release uses the terms "Measured", "Indicated", and "Inferred" resources. U.S. investors are advised that while such terms are recognized and required by Canadian regulations, the United States Securities and Exchange Commission does not recognize them. "Inferred Mineral Resources" have a great amount of uncertainty as to their existence, and as to their economic and legal feasibility. It cannot be assumed that all or any part of an Inferred Mineral Resource will ever be upgraded to a higher category. Under Canadian rules, estimates of Inferred Mineral Resources may not form the basis of feasibility or other economic studies. U.S. investors are cautioned not to assume that all or any part of Measured or Indicated Mineral Resources will ever be converted into Mineral Reserves. U.S. Investors are also cautioned not to assume that all or any part of a Mineral Resource is economically or legally mineable.
2013 number 14