Rye Patch Reports Metallurgical Results From Wilco
VANCOUVER, BRITISH COLUMBIA -- (Marketwire) -- 07/27/11 -- Rye Patch Gold Corp. (TSX VENTURE: RPM)(OTCQX: RPMGF) ('Rye Patch' or the 'Company') reports the results of CIL bottle roll tests and diagnostic leaching from the Section Line resource and North Basin drill target.
HIGHLIGHTS
-- Gold recoveries from CIL bottle roll testing shows 50% to 92% gold
recovery within the Section Line resource;
-- Silver recoveries from CIL bottle roll testing returned 25% to 88%
silver recovery within the Section Line resource;
-- Gold extractions associated with diagnostic leach testing range from 73%
to 91% for direct cyanide leaching and simple sulfide leaching;
-- Overall gold extractions associated with diagnostic leach through all
testing ranged from 79% to 96%; and
-- The majority of the gold within the Section Line and North Basin target
is associated with native gold occurring on the outside of veins and
mineral grain boundaries.
DISCUSSION
Seventeen composite samples were submitted to Kappes, Cassidy and Associates (KCA) in Reno, Nevada, for CIL bottle roll testing and diagnostic metallurgical testing. Nine composites are from the Section Line resource and consist of reverse circulation and core samples. In the North Basin area, eight composites were selected from reverse circulation drilling in the target area. As a final analysis, five composites were selected for diagnostic leaching - two from North Basin and three from the Section Line resource.
The results of the CIL bottle-roll analyses conform well with Rye Patch Gold's oxide domain model used in the resource estimate. The axial zone of the Section Line anticline contains the bulk of the oxide material. As mineralization moves outward along the limbs of the antiform, oxidation attenuates to the north toward the North Basin target. The bulk of the Section Line resource sits within the anticline and is open to the west. Higher grade are along the northern limb of the anticline. Table 1 summarizes CIL bottle roll gold and silver extractions.
'I am very pleased with the results of the bottle roll test and quite excited by the diagnostic leach tests. Both analyses show the gold and silver are associated with free gold and simple sulfides which can be treated using existing technologies employed in gold mining in Nevada. Obviously, additional testing is required to fully understand the gold and maximize value from the deposit; however, this is an excellent first step,' stated William C. (Bill) Howald, the Company's President and CEO.
Table 1: CIL Bottle Roll Leach Tests; Summary of Gold and Silver Extractions
----------------------------------------------------------------------------
Ex- Ex- Consum-
Sam- tra- tra- ption Add'l
Sample ple Drill Head cted Head cted NaCN Ca(OH)2
ID Type Interval Au opt Au % Ag opt Ag % lbs/st lbs/st Area
----------------------------------------------------------------------------
WR-040 RC 130-250 0.095 92% 0.05 45% 4.02 1.50 Section Line
WR-040 RC 250-305 0.024 90% 0.07 25% 3.33 1.50 Section Line
229-
281,199-
WRC- 219,182-
1/2/3 Core 201.5 0.018 65% 0.31 77% 3.31 2.50 Section Line
WRC-3 Core 201.5-235 0.038 66% 0.24 26% 3.00 1.50 Section Line
WRC-1 Core 598-623.5 0.015 69% 0.13 66% 2.50 1.50 Section Line
556-
596,574-
WRC2/3 Core 590 0.034 55% 0.34 75% 3.01 1.50 Section Line
WRC-4 Core 209-602 0.018 54% 0.10 67% 2.65 1.50 Section Line
WRC-4 Core 602-623 0.016 50% 0.10 58% 2.48 1.50 Section Line
WRC-4 Core 536-712 0.034 60% 0.17 88% 2.58 1.50 Section Line
WR-081 RC 1120-1160 0.047 59% 0.24 75% 2.84 1.50 North Basin
WR-081 RC 1210-1240 0.030 20% 0.10 22% 3.35 2.00 North Basin
WR-098 RC 1090-1190 0.047 48% 0.20 6% 2.84 2.00 North Basin
WR-105 RC 410-500 0.012 55% 0.12 48% 3.50 1.50 North Basin
WR-105 RC 1105-1165 0.048 44% 0.56 72% 3.19 2.00 North Basin
WR-081 RC 1160-1210 0.076 59% 1.03 79% 3.19 1.00 North Basin
WR-098 RC 1155-1210 0.039 47% 0.10 36% 2.91 2.00 North Basin
WR-098 RC 1100-1155 0.040 62% 0.11 64% 3.02 1.50 North Basin
----------------------------------------------------------------------------
In addition to the CIL bottle roll analysis, KCA performed diagnostic leaching on five samples - WR-081, WR-105, WRC-1, WRC-2/3 and WRC-4. Diagnostic leach testing is designed to determine the metal association within a sample material by leaching the material in six stages with various pretreatments for each stage. Following the pretreatments, the residues were leached in CIL bottle roll tests with 10 pound per ton (5.0 gram per liter) sodium cyanide solution.
The remaining gold not leached in any stage of the diagnostic testing was presumed to be encapsulated in the remaining minerals. The test work was conducted utilizing material pulverized to a target 80% passing 200 mesh Tyler. Accordingly, if the particle size were reduced to a finer size than that utilized for this test work, the gold extraction should increase.
Table 2: Comparison of Diagnostic Direct Leach Au Extraction and CIL Bottle Roll Au Extraction
-----------------------------------------------------------
Diagnostic Direct Leach Previous CIL
KCA Sample No. Au Extracted Au Extracted
-----------------------------------------------------------
WR-081 14% 20%
-----------------------------------------------------------
WR-105 50% 55%
-----------------------------------------------------------
WRC-1 83% 69%
-----------------------------------------------------------
WRC2/3 62% 55%
-----------------------------------------------------------
WRC-4 54% 50%
-----------------------------------------------------------
To view the results of the diagnostic leach test work in graph form (Figure 1) please visit the following link: http://media3.marketwire.com/docs/rpm27-Fig1.pdf
Three of the five composites tested showed an increase in the gold extraction during the direct leach stage of the diagnostic program versus the previously conducted CIL. The other two composites showed a decrease in the gold extraction versus the previous CIL tests. The tests differed in two areas, cyanide concentration and leach time. These results suggest some composites responded better to increased cyanide additions while others responded better to increased leach periods.
Four of the five composites tested showed the majority of gold extraction occurred during the direct cyanide leach. In four of the five composites, the gold associated with arsenopyrite and some pyrite constituted the second largest contribution to overall extraction. The overall gold extractions in the diagnostic leach tests ranged from 79% to 96%. Notably, 73% to 91% of the total gold extraction in the diagnostic leach testing was attributed to the direct cyanide and arsenopyrite leach stages.The gold extractions associated with the diagnostic leach testing from direct cyanide leaching through simple sulfide leaching ranged from 73% to 91% and the overall extractions through all testing ranged from 79% to 96%.
PROCEDURES
The procedure utilized for the CIL bottle roll testing is as follows. First, a 1,000 gram portion of pulverized material was placed into a 2.5 liter bottle and slurried with the addition of 1,500 milliliters of water and 75 grams of granular activated carbon (GAC). The slurry was mixed thoroughly and the pH of the slurry was checked. The pH of the slurry was adjusted, as required, to 11.0 with hydrated lime.
Sodium cyanide was added to the slurry to equal 2 pounds per ton of water added (1.0 grams per liter). The bottle was then placed onto a set of laboratory-rolls. Rolling throughout the duration of the test mixed the slurry. The slurry was checked at 2, 4, 8, 24, 48, 72 and 96 hours for pH, dissolved oxygen (DO), NaCN, Au, Ag and Cu.
After completion of the leach period, the slurry was screened to remove the carbon. The screened slurry was then washed, filtered and dried.
Duplicate portions were split from the tailings and assayed for residual gold and silver content. The screened carbon was dried and assayed for gold and silver content. The results of the bottle roll leach test are summarized in Table 1.
Diagnostic leach testing is designed to determine the metal association within a sample material by leaching the material in six stages with various pretreatments for each stage. For this testing, five (5) separate composite samples were selected based on location. Leaching was conducted on a pulverized (80% passing 200 mesh Tyler) portion of material from each composite.
As announced on May 18, 2010, May 11, 2009, and June 2, 2009, in respect of the Lincoln Hill, Wilco, and Jessup projects, Rye Patch Gold's resource inventory along the Oreana trend now totals 1,182,780 ounces of gold and gold equivalent in the measured and indicated category plus 2,727,100 ounces of gold and gold equivalent in the inferred category. Table 2 summarizes Rye Patch Gold's precious metal inventory in Nevada, USA.
----------------------------------------------------------------------------
Table 2: Rye Patch Gold's NI43-101 Resource Inventory(1)
----------------------------------------------------------------------------
Contained
Gold &
Tonnes Gold Silver Contained Contained Gold
Resource (X Grade Grade Gold Silver Equivalent
Property Category 1,000) (g/t) (g/t) Ounces Ounces Ounces(4)
----------------------------------------------------------------------------
Wilco(2) Measured 7,526 0.69 4.595 164,000 1,111,000 186,220
Indicated 30,844 0.51 3.601 522,000 3,638,000 594,760
Inferred 121,838 0.41 5.075 1,660,000 19,871,000 2,057,420
----------------------------------------------------------------------------
Jessup Measured 7,775 0.51 8.745 128,000 2,184,000 171,680
(2) Indicated 12,642 0.41 7.167 172,000 2,906,000 230,120
Inferred 4,494 0.55 7.922 77,000 1,146,000 99,920
----------------------------------------------------------------------------
Lincoln Measured - - - - - -
Hill(3) Indicated - - - - - -
Inferred 17,215 0.69 17.143 380,000 9,488,000 569,760
----------------------------------------------------------------------------
Total Oreana Trend Measured & Indicated
Resources 986,000 9,839,000 1,182,780
Total Oreana Trend Inferred Resources 2,117,000 30,505,000 2,727,100
----------------------------------------------------------------------------
----------------------------------------------------------------------------
(1) All resources on 100% basis. Metallurgical recoveries and net smelter
returns are assumed to be 100%. Conforms to 43-101 resource definitions;
(2) Cutoff grade for Wilco Measured and Indicated resource is reported at
0.2 g/t Au for oxide mineralisation and 1.45 g/t Au for sulphide
mineralisation. The Inferred resource cut-off grade is reported at 0.2 g/t
Au for oxide, sulphide and carbonaceous ore types; however, a higher opt Au
cut-off grade may be required to upgrade the inferred resource to the
measured and indicated resource category. Cut-off grade for Jessup is
reported at 0.2 g/t Au for oxide mineralisation and 0.34 g/t Au for
transition and sulphide mineralisation; and
(3) The Inferred resource is reported at a cut-off grade of 0.34 g/t (0.01
opt) Aueq for oxide and transitional ore types;
(4) Wilco, Jessup and Lincoln Hill resources includes Au equivalent ounces
(Aueq.); where Aueq. = (Au ozs) (Ag ozs X $Ag/oz)/$Au/oz, for Au/oz =
$900, and Ag/oz = $18
----------------------------------------------------------------------------
Mr. William Howald, AIPG Certified Professional Geologist #11041, Rye Patch Gold's CEO and President, is a Qualified Person as defined under National Instrument 43-101. He has verified the information contained in, and has reviewed and approved the contents of, this news release.
Rye Patch Gold Corp. is exploring well-known mineral trends in Nevada - the world's fourth-richest gold region. Starting with 150,000 inferred ounces of gold in mid-2007, this well-funded Company now has 1.2-million ounces of gold and gold equivalent in the measured and indicated category, plus 2.7-million ounces of gold and gold equivalent in the inferred category. Rye Patch Gold is a Tier 1, Nevada-focused and discovery-driven company seeking to build a sizeable inventory of gold and silver resource assets in the mining friendly state of Nevada, USA. The Company's seasoned management team is engaged in acquisition, exploration and development of quality resource-based gold and silver projects. Rye Patch Gold is developing its primary assets - the advanced-stage Wilco, Lincoln Hill, Jessup, and Gold Ridge projects located along the emerging Oreana gold trend in west-central Nevada. The Company has established gold and silver resource milestones and time frames in order to build a premier resource development company. For more information about Rye Patch Gold, please visit our website at www.ryepatchgold.com.
This news release contains forward-looking statements, which address future events and conditions, which are subject to various risks and uncertainties. The Company's actual results, programs and financial position could differ materially from those anticipated in such forward-looking statements as a result of numerous factors, some of which may be beyond the Company's control. These factors include: the availability of funds; the timing and content of work programs; results of exploration activities and development of mineral properties, the interpretation of drilling results and other geological data, the uncertainties of resource and reserve estimations, receipt and security of mineral property titles; project cost overruns or unanticipated costs and expenses, fluctuations in metal prices; currency fluctuations; and general market and industry conditions.
Forward-looking statements are based on the expectations and opinions of the Company's management on the date the statements are made. The assumptions used in the preparation of such statements, although considered reasonable at the time of preparation, may prove to be imprecise and, as such, undue reliance should not be placed on forward-looking statements.
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.
Contacts:
Rye Patch Gold Corp.
William C. (Bill) Howald
CEO & President
(604) 638-1588
(604) 638-1589 (FAX)
info@ryepatchgold.com
www.ryepatchgold.com