17th Dec 2014 07:00
Ortac Resources Ltd / Epic: OTC / Market: AIM / Sector: Mining & Exploration 2014
17th December 2014
Ortac Resources Ltd
("Ortac" or "the Company")
UPDATE ON ŠTUREC DEPOSIT
Encouraging Results from Thiosulphate Testwork
Ortac Resources Ltd, the AIM listed exploration and mine development company, is pleased to announce the results from an 8 tonne bulk sample recently mined from the Company's Šturec deposit in Slovakia, sent for pilot scale thiosulphate leaching tests which suggest that the development of a cyanide-free process is a step closer.
Highlights:
· Gold and silver recoveries of 90.5% and 48.9%, respectively;
· Ortac is working with CMC Chimie S.R.L. ("CMC") and interested third parties on the development of the CMC patented processing technology, using thiosulphate leaching techniques;
· Results from bulk sample exceed expectations and provide Ortac with an opportunity for the development of a cyanide-free investment partnership; and
· Use of thiosulphate in gold extraction processes is currently being implemented by an industry leader and promises environmental benefits.
Commenting on today's news, Vassilios Carellas, Ortac's CEO, said:
"These results have exceeded our expectations and afford us a real opportunity for the development of a cyanide-free investment partnership linked to the development of the Šturec Deposit in Slovakia, and perhaps even other deposits elsewhere. These pilot scale tests support earlier laboratory scale testwork, which was carried out on much smaller sample sizes. It is significant that the use of thiosulphate promises environmental benefits, as it is commonly used as a fertilizer and, as such, is considered to be non-toxic.
"The use of thiosulphate in gold extraction processes is currently being implemented by Barrick Gold Corporation, to recover gold from their Goldstrike Complex Project in Nevada, USA.
"Ortac is working with CMC on the development of the CMC patented processing technology, which has now demonstrated that good recoveries of gold and silver in both laboratory and larger pilot scale testing can be achieved. The CMC method represents a different approach to cyanide based hydrometallurgical processing and Ortac is now in discussions with interested third parties in scaling up and commercialising the CMC technology."
Summary and Full Results
CMC Chimie S.R.L. ("CMC") is a private Romanian company set up to develop innovative eco-friendly technologies in the processing of gold and silver ores. CMC is part of CMC Group and its gold and silver processing technology, which uses a thiosulphate compound as a lixiviant, was established and patented by their team during 2007 - 2013. The team is spearheaded by inventor Dr Jack Goldstein who has been carrying out research and testwork on thiosulphate based compounds for a number of years and has patented a number of processes using these compounds.
CMC's report presents results of the Vat leaching of gold ore, recently extracted from an adit under Šturec, following on from Ortac being granted a license to perform small scale underground mining. Following shipment to CMC, the Šturec ore was ground in a continuous dry ball mill to a particle size with a d99 of approximately 699µm.
Ore dissolution was carried out on ten batches of ore of approximately 800kg each, leaching at ambient temperatures and using solutions recirculated after the electrowinning process, along with the addition of reagents and a copper catalyst. Agitated leaching for approximately 2-4 hours took place in a 2.5m3 reactor, with each batch settled, solution decanted and solids filtered and washed with water. The average dissolution for the ten batches at this stage in the process averaged 92.3% for gold and 49.99% for silver.
The decanted solution obtained after dissolution was subjected to electrowinning, following which the slurry produced was decanted and filtered, producing a concentrate containing copper, gold and silver. The overall gold and silver recovery to cement is reported to be 90.5% and 48.9%, respectively, with early indications according to CMC that the cost price for processing is comparable to that of cyanide.
The information in this release is based on information provided by CMC Chimie S.R.L. and compiled on behalf of Ortac by Owen Mihalop (MCSM, BSc (Hons), MSc, MIMMM, CEng) Technical Director for Ortac Resources Limited. Mr. Mihalop has sufficient experience relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking to qualify as a Competent Person as defined under the JORC Code (2012) and as a Qualified Person under NI 43-101. Mr. Mihalop consents to the inclusion in this announcement of the matters based on his information in the form and context in which it appears.
---ENDS---
Glossary
Thiosulphate - an oxyanion of sulphur with the chemical symbol S2O32.
Lixiviant - a liquid medium used in hydrometallurgy to selectively extract the desired metal from the ore or mineral.
Vat leaching - a hydrometallurgical method of extracting valuable material from ore.
Ore - a type of rock that contains sufficient minerals or metals that can be economically extracted from the rock.
For additional information please visit - www.ortacresources.com
Ortac Resources Ltd Vassilios Carellas (CEO)
| +44 (0) 20 7389 9050 |
Cantor Fitzgerald Europe (Nominated Adviser & Broker) Stewart Dickson / Carrie Lun / Jeremy Stephenson
| +44 (0) 20 7894 7000 |
SP Angel (Broker) Ewan Leggat Loeb Aron & Co. (Broker) John Beresford-Peirse/Anthony Kluk
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