N E W S R E L E A S E
Grayd Reports Excellent Gold Recoveries in Column Tests at La India
Vancouver, BC, August 11, 2008 . . .. Grayd Resource Corporation (TSX-V: GYD) announces results from recently completed cyanide column leach tests on mineralized samples from its wholly owned La India Gold Project located in the state of Sonora, Mexico. Test work indicates that average gold recoveries of 78% should be achievable in a heap leach processing operation if the rock is crushed to -12.5 to -50 mm (1/2 to 2 inch). These recoveries, combined with relatively low estimated cyanide and lime consumptions, are very positive factors for potential project economics. An estimated stripping ratio of 0.35:1 (waste to ore) based on the January 2008 inferred resource is another positive economic factor.
Thirteen column tests with material derived from 2007 core drilling were conducted at Kappes, Cassiday & Associates (KCA) of Reno, Nevada. Tests were run on seven composites of different rock types and gold grades. Six composites were run at crush sizes of -50 mm and -12.5 mm. One composite, of high grade material from the Cieneguita zone, was only run at -12.5 mm as there was insufficient material to produce a -50 mm sample.
Recoveries for the -12.5 mm columns ranged from 62% to 94% and for the -50 mm columns ranged from 46% to 90%. Average recoveries for the columns are 79% (-12 mm) and 69% (-50 mm, does not include a Cieneguita high-grade column). Three of the -50 mm columns had about the same recovery as the -12.5 mm columns with an average of 86% for the three columns. The other three composites had 15% higher average gold recovery in the -12.5 mm over the -50 mm columns. The geological model for the property is currently being revised. Preliminary interpretations of rock type volumes in the deposit in conjunction with the column test results indicate a weighted average recovery for all rock types in the deposit would be 78% in an operating heap leach operation based on crushing all the rock to -50 mm and half to -12.5 mm. Additional work to determine recoveries on run-of-mine material will be undertaken on rock types with high recoveries at -50 mm. Additional testing on higher grade material is also planned.
A preliminary evaluation of open pit potential was undertaken by Moose Mountain Technical Services on the January 2008 inferred resource model. This work determined that waste to ore ratios would be in the range of 0.2:1.0 to 0.35:1.0 depending upon gold price, recovery and mining costs.
Core and reverse circulation (RC) drilling are continuing on the site. Core will be used to help create the new geological model, verify RC results and provide material for additional metallurgy. Core drilling will be completed by mid August. RC drilling to upgrade and expand the resource areas should be completed in the first half of September. Drilling thereafter will evaluate new targets derived from ongoing mapping and sampling. A new resource will be calculated in the fourth quarter of 2008 incorporating the additional drilling and the new geological model.
A summary table of column test results is attached. Maps showing resource areas are posted on Grayd?s website (www.grayd.com). Hans Smit, P.Geo., VP Exploration for Grayd, is the Qualified Person directing the exploration at La India. Test work at KCA was under the supervision of Terence Albert, Manager of Laboratory Services and Daniel Kappes, P.Eng., Qualified Person for KCA. Jim Gray, P.Eng. was the Qualified Person for the preliminary evaluation by Moose Mountain Technical Services.
Sample Identification |
Average Head Assay, gms Au/MT |
Calculated Head, gms Au/MT |
Extracted, gms Au/MT |
Weighted Avg. Tail Screen, gms Au/MT |
Extracted, % Au |
Tail Calculated P80 Ore Size, mm |
Crush Size, mm |
Days of Leach |
Consumption NaCN, kg/MT |
Addition Hydrated Lime, kg/MT |
Silica Structure - La Cruz, Cerro de Oro |
1.69 |
1.71 |
1.31 |
0.40 |
77% |
43.45 |
-50 |
126 |
0.53 |
1.00 |
Silica Structure - La Cruz, Cerro de Oro |
1.69 |
1.77 |
1.44 |
0.33 |
81% |
8.90 |
-12.5 |
140 |
0.88 |
2.00 |
|
|
|
|
|
|
|
|
|
|
|
Silica Clay - La Cruz |
0.48 |
0.51 |
0.46 |
0.05 |
90% |
35.68 |
-50 |
126 |
2.43 |
2.26 |
Silica Clay - La Cruz |
0.48 |
0.45 |
0.40 |
0.05 |
89% |
7.72 |
-12.5 |
126 |
2.03 |
0.00 |
|
|
|
|
|
|
|
|
|
|
|
Dacite - SC/SA - Viruela |
1.24 |
0.97 |
0.88 |
0.09 |
91% |
37.08 |
-50 |
126 |
0.86 |
2.00 |
Dacite - SC/SA - Viruela |
1.24 |
1.12 |
1.01 |
0.11 |
90% |
7.96 |
-12.5 |
126 |
1.29 |
0.00 |
|
|
|
|
|
|
|
|
|
|
|
Silica Massive - Viruela |
1.15 |
1.06 |
0.49 |
0.57 |
46% |
45.08 |
-50 |
126 |
0.64 |
1.00 |
Silica Massive - Viruela |
1.15 |
0.98 |
0.70 |
0.28 |
71% |
8.89 |
-12.5 |
126 |
0.78 |
1.00 |
|
|
|
|
|
|
|
|
|
|
|
Andesite SA/SV |
2.45 |
2.27 |
1.27 |
1.00 |
56% |
43.87 |
-50 |
126 |
0.68 |
1.00 |
Andesite SA/SV |
2.45 |
2.35 |
1.54 |
0.81 |
66% |
8.51 |
-12.5 |
126 |
1.03 |
3.00 |
|
|
|
|
|
|
|
|
|
|
|
Silica Massive - Cieneguita |
0.40 |
0.39 |
0.20 |
0.19 |
51% |
41.97 |
-50 |
126 |
0.57 |
1.00 |
Silica Massive - Cieneguita |
0.40 |
0.40 |
0.25 |
0.15 |
62% |
8.76 |
-12.5 |
140 |
1.03 |
2.00 |
|
|
|
|
|
|
|
|
|
|
|
Cieneguita - High Grade |
9.00 |
9.01 |
8.46 |
0.55 |
94% |
8.67 |
-12.5 |
126 |
3.22 |
3.03 |
Grayd Resource is a growth-oriented junior natural resource company focused primarily on exploring and developing a large land position in Mexico which is highly prospective for gold and silver mineralization. The Company's Officers and Directors are experienced in all aspects of mineral exploration, development and production and have been involved with several successful mining projects during the past 20 years. For further information, please contact Marc A. Prefontaine ? President and CEO (604-681-7446) or www.grayd.com
The TSX Venture Exchange has neither approved nor disapproved of the information contained herein.
The information in this news release may contain forward-looking statements. When used in this release, words such as ?estimate?, ?expect?, ?anticipate? and ?believe? as well as similar expression are intended to identify forward-looking statements. Such statements are used to describe management?s future plans, objects, and goals for the Company and therefore involve inherent risks and uncertainties. The reader is cautioned that actual results, performance or achievements may be materially different from those implied or expressed in such statements, which speak only as of the date the statements were made. The Company does not update forward-looking statements continually as conditions change.