Grayd Increases Gold Recoveries at La India
November 20 2009 - 7:30AM
Marketwired
Grayd Resource Corporation (TSX VENTURE: GYD) today reported that
recently completed test work has increased the estimated overall
recovery of gold to between 80% and 84% for its wholly owned La
India heap leach gold project located in Sonora State, Mexico.
Grayd's President and Chief Executive Officer, Marc Prefontaine,
said, "This is very good news for the economics of the La India
gold project. These most recent tests indicate not only improved
recoveries, but also that the crush size for the rock can be
larger, which could save significant operating costs."
The updated overall recovery estimates on the resource was
determined by Grayd and are based on seven new column leach tests
completed at Kappes, Cassiday & Associates (KCA) of Reno,
Nevada, in conjunction with the results from previous test work at
KCA reported on August 11, 2008. The new tests were undertaken to
better quantify recoveries and optimal crush size on rock types
which contain significant amounts of oxide gold in the current
resource.
Two of the new composite samples were comprised of material from
five core holes drilled in the North Zone. Each composite was
tested at -25 mm (-1 inch) and -9.5 mm (-3/8 inch). Recoveries were
96% and 97% at -25 mm and slightly lower at 95% and 93% for the
finer -9.5 mm crush size. One composite was made up of core from
five drill holes in the Main Zone and was tested at the same two
crush sizes. It had recoveries of 80% at -25 mm and 79% at -9.5 mm.
One sample of high grade material from within a structurally
controlled feeder in the Main Zone was tested at -9.5 mm and had a
recovery of 94%.
KCA normally discounts laboratory gold recoveries by two to
three percentage points when estimating field recoveries. Based on
the relative volumes of different rock types in the current
resource and the results of the recent and 2008 tests, an average
gold recovery in the range of 80% to 84% is indicated for a heap
leach processing operation at La India. The similarity in
recoveries for the two crush sizes is important economically as it
indicates that the material tested will only need to be crushed to
- 25mm (-1 inch). Additional test work on other rock types at the
-25 mm size will be undertaken. Most of the gold was recovered in
the first 20 days of leaching, although the columns were leached
for 91 to 104 days. Lime and cyanide consumptions were relatively
low. These are all positive factors for the economics of a
potential mine.
Material for the tests was collected by Grayd from the remaining
half-core of holes drilled in 2008. Samples were sent to the KCA
laboratory in Reno where composites were created. In addition to
the column leach tests, KCA undertook a series of grade, physical
and environmental analyses. 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. Maps showing the location of the drill
holes where samples were taken from are posted on Grayd's website
(www.grayd.com).
Summary of 2009 Column Leach Tests
---------------------------------------------------------------------------
Weighted Addi-
Calcu- Avg. tion
Sample lated Extrac- Tail Consum- Hydr- Addi-
Identi- Head, ted, Screen, Extrac- Crush Days ption ated tion
fica- gms gms gms ted, Size, of NaCN, Lime, Cement,
tion Au/MT Au/MT Au/MT % Au mm Leach kg/MT kg/MT kg/MT
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Main
Zone
SV-SA 1.65 1.32 0.33 80% -25 91 0.81 2.01 0.00
---------------------------------------------------------------------------
Main
Zone
SV-SA 1.55 1.22 0.33 79% -9.5 104 0.77 0.00 3.00
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Main
Zone-
High
Grade 13.25 12.47 0.78 94% -9.5 91 1.60 0.00 2.99
---------------------------------------------------------------------------
---------------------------------------------------------------------------
North
Zone
SM-CE 1.08 1.04 0.04 96% -25 91 0.82 2.01 0.00
---------------------------------------------------------------------------
North
Zone
SM-CE 1.09 1.03 0.06 95% -9.5 104 0.92 0.00 3.01
---------------------------------------------------------------------------
---------------------------------------------------------------------------
North
Zone
SM-ES 1.16 1.12 0.04 97% -25 91 0.88 2.10 0.00
---------------------------------------------------------------------------
North
Zone
SM-ES 1.04 0.97 0.07 93% -9.5 104 0.83 0.00 2.98
---------------------------------------------------------------------------
The La India gold project is located in the prolific Mulatos
gold belt of Mexico's Sonora State. The project has a NI43-101
compliant gold resource of 559,000 ounces grading 1.01 g/t in the
indicated category and 318,000 ounces grading 1.05 g/t in the
inferred category, all at a 0.5 g/t cut-off grade. The resource
consists of 17.2 and 9.4 million tonnes of indicated and inferred
material, respectively. This same district hosts Alamos Gold's
Mulatos mine, which produced 151,000 ounces of gold in 2008 and had
a reported resource of 4.75 million ounces of gold at the end of
2008.
Grayd Resource is a growth-oriented junior natural resource
company focused primarily on identifying, exploring and developing
precious metal deposits. The Company's Officers and Directors are
very experienced in all aspects of mineral exploration, development
and production and have been involved in a number of successful
mining projects around the world over the past 20 years.
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.
The TSX Venture Exchange has neither approved nor disapproved of
the information contained herein.
Contacts: Grayd Resource Corporation Marc A. Prefontaine
President and CEO 604-681-7446 604-684-9877 (FAX) www.grayd.com
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