Gold Recoveries Up To 80% At Cerro Prieto
June 10, 2010
VANCOUVER, British Columbia – (June 10, 2010) Oroco Resource Corp. (TSX-V: OCO) (“Oroco” or “the Company”) is pleased to announce the results of its recently completed second phase metallurgical testing of samples from the Cerro Prieto project in Sonora State, Mexico. The metallurgical testing has shown recoveries of gold of up to 80%.
The Company retained Kappes Cassidy & Associates (“KCA”), of Reno Nevada, under the direction of the Company’s metallurgical consultant, A.H. Winckers & Associates Inc., to conduct column leach tests of four representative composite samples of mineralized material taken from four separate areas of the Cerro Prieto deposit. Test work at KCA was under the supervision of Terence Albert, manager of Laboratory Services and Daniel Kappes, PEng, qualified person for KCA.
A summary of the column test recovery results is presented in the following table:
| Zone |
Size
(mm) |
Head Grade
(g/t) |
Days |
Extracted Gold (%) |
NaCN
(kg/t) |
Ca(OH)2
(kg/t) |
| 1 |
25.0/6.3 |
0.95 |
140 |
80 |
0.74 |
2.02 |
| 2 |
25.0/6.3 |
0.79 |
140 |
66 |
0.91 |
2.05 |
| 3-Upper |
6.3 |
1.50 |
81 |
61* |
1.48 |
7.5 |
| 3-Lower |
6.3 |
0.90 |
81 |
77* |
1.60 |
7.5 |
* Interim results; leaching to continue for a minimum of an additional 30 days.
Additional metallurgical testing is being planned to further refine the extraction process.
Zone 1 encompasses the first 550 meters of the mineralized zone, measured horizontally from the south end of the deposit and from surface to a depth of 150 meters. The sample taken from this zone was a composite of mineralized core from four drill holes. Zone 1 holds the higher grade material in the deposit and, being situated at the top of the deposit, would potentially be the first area mined.
Zone 2 encompasses the area immediately below Zone 1 to a depth of approximately 350 meters. The sample from this zone was a composite of mineralized core from eight drill holes.
Zone 3 – Upper encompasses the 400 meters of strike length immediately to the north of Zone 1 to a depth of 150 meters. The mineralize sample was taken from four drill holes.
Zone 3 – Lower encompasses the area immediately below Zone 3 – Upper to a depth of 300 meters. The mineralized sample was taken from six drill holes.
Column leach tests on the samples from Zone 1 and Zone 2 were initially conducted at minus 25 mm and minus 12.5 mm crush sizes. After 98 days of leaching, gold extraction ranged from 68% for a Zone 1 sample to 47% for a Zone 2 sample, with sodium cyanide consumption ranging from 0.74 kg/t to 0.91 kg/t and hydrated lime additions ranging from 2.02 kg/t to 2.05 kg/t. After 98 days, the minus 25 mm sample was crushed to 6.3 mm and retested. Indicated cumulative results are 80% from the Zone 1 sample and 66% from the Zone 2 sample.
Column leach tests on the samples from Zone 3 – Upper and Zone 3 – Lower are still in process using a 6.3 mm crush size. The leaching process has now been active for 81 days and will continue for a minimum of another 30 days. Results to date show recoveries of 77% from the Zone 3 – Lower sample and 61% for the Zone 3 – Upper sample.
Craig Dalziel, Oroco’s President, stated: “The Company is very pleased with the results of the metallurgical testing to date. An 80% recovery in Zone 1, which holds the higher grade material in the deposit, will enhance the early economic potential of our anticipated heap leach mining operation.”
About Oroco
Oroco is a Canadian-based mineral exploration company with its primary focus on the accelerated development of the gold-bearing oxide zones of its Cerro Prieto project in northern Sonora State, Mexico. The Cerro Prieto Project consists of the 100% owned San Felix, San Francisco and Cerro Prieto concessions, totalling 2,723 ha, and 4,120 ha of the contiguous Argonauta 5 Fraccion 1 concession to which the Company holds an option to purchase.
For further information, please contact:
Mr. Craig Dalziel, President and CEO
Oroco Resource Corp.
Tel: 604-688-6200
www.orocoresourcecorp.com
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.
