Prior to conducting a column leach study, an agitated cyanide leach study (bottle roll) was conducted on four samples at minus 10 mesh and 150 mesh (pulverized) crush sizes to compare oxide to sulfide recoveries and determine reagent consumption. The Moss Mine deposit contains minor pyrite below a depth of approximately 200 feet. The results of the 96 hour test, shown below, indicate similar extraction percentages for sulfide and oxide. This indicates that even the deeper, un-oxidized mineralization at Moss may be leachable. Reagent consumption was minimal.
Moss Mine Project Preliminary Bottle Roll Cyanide Leach Tests - Oxide and Sulfide Composite Samples
The locked cycle column leach tests were conducted on the Moss core at 80 percent passing 1 inch, 1/2 inch and 1/4 inch crush sizes. Three test charges were reconstituted and loaded into 4 inch diameter PVC columns to a height of approximately 3.5 meters. Prior to loading the columns, the sample was agglomerated with water and lime. The columns were leached for 109 days.
Gold extraction ranged from 39 to 66 percent and silver extraction ranged from 14 to 42 percent depending on crush size as shown in the table below. Reagent consumption was again minimal.
MOSS MINE PROJECT- Oxide Composite Sample
Crush Size Locked Cycle Column Leach Study
Summary of Results
Calculated Head (g/t)
P80 1 inch
P80 1/2 inch
P80 1/4 inch
Column leach results indicate the Moss mineralization is leachable. At the end of the 109 day test all three samples were still contributing gold/silver to the leach solution. This indicates longer leach times will improve recoveries. A graph of gold/silver recoveries is on the company's website.
At Round Mountain, Nevada and several other heap leach operations in Nevada leaching is conducted for several years on the same leach pile. The success of this initial metallurgy indicates the Moss Mine deposit may be minable at a lower cut-off grade thus allowing mining to greater depth. Patriot plans an additional drilling program to expand the resource down-dip, a resource calculation and further metallurgy using longer column leach times.
Disclaimer: This announcement may contain forward-looking statements which involve risks and uncertainties that include, among others, limited operating history, limited access to operating capital, factors detailed in the accuracy of geological and geophysical results including drilling and assay reports; the ability to close the acquisition of mineral exploration properties, and other factors which may cause the actual results, performance or achievements of the company to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. More information is included in the company's filings with the Securities and Exchange Commission, and may be accessed through the SEC's web site at http://www.sec.gov.