Inter-Citic Reports New Metallurgical Work at Dachang Exceeds Previous Results Metallurgical Testwork Increases Recovery of Gold to Dore at Dachang and Goldfields Confirms BIOX(R) Suitability
Metallurgical Testwork Increases Recovery of Gold to Dore at Dachang and Goldfields Confirms BIOX(R) Suitability
TORONTO, ONTARIO -- (Marketwire) -- 03/02/11 -- Inter-Citic Minerals Inc. (TSX: ICI) ('Inter-Citic' or 'the Company') President and CEO James Moore, is pleased to provide an update of the metallurgical testwork carried out as part of its ongoing flowsheet development work, aimed at permitting and constructing a gold mine and associated concentrator and bacterial oxidation plant, at its Dachang Gold Project in Qinghai Province in China.
This extensive optimization testwork resulted in an estimated overall predictable recovery of gold from typical Dachang mineralization of 87.8% to dore, up from 85% previously reported by the Company and used in its Preliminary Economic Assessment announced July 6, 2009.
Over the past 6 months the Company has carried out multiple metallurgical testwork programs in both China and overseas in Australia and in South Africa. The aim of these programs has been to confirm the earlier testwork reported on by the Company on March 2nd and May 7th 2009, and to provide increased certainty as to metallurgical performance of the proposed treatment route for the production of gold in dore from the Dachang Project. This work was supervised by the Company's independent technical expert for metallurgy, Gary A. Patrick, B.Sc., MAusIMM, who is the principal of Metallurg Pty. Ltd. and a Qualified Person under NI 43-101. The testwork was completed at independent laboratories and testwork facilities both in China and overseas.
In November of 2010, a number of fresh samples of Dachang mineralization were collected to test for variability of flotation response within the Dachang ore body. Samples were collected throughout the Dachang Main Zone and Placer Valley Zone areas of the property and split into two sub-samples, to be sent for comparative testing at both the Beijing General Research Institute Of Mining & Metallurgy ('BGRIMM') in Beijing and at AMMTEC in Australia.
Results from the AMMTEC bulk flotation tests were 94.93% recovery, at a concentrate grade of 31.59 gpt gold. The variability flotation tests also showed no significant variation in metallurgical performance and all lithology types floated well. Optimum grind size for the AMMTEC testwork was determined to be 80% passing 106 microns. AMMTEC also completed settling tests on the concentrate and tailings products, and filtration tests on the concentrate product to aid in the detailed engineering design process.
BGRIMM's results for the same sample were marginally lower than AMMTEC, but the Company considers these differences to be within the acceptable limits and attributes the variability to different operator experience.
At the same time, approximately 30 kg of low-grade concentrate from the Extended Continuous Flotation Test ('ECT') averaging 26.9 gpt gold, 8.6% S2-, and 4.48% As, was shipped to SGS Laboratories, Johannesburg for bacterial oxidation and BIOX® testwork. The batch and bulk Batch Amenability Testwork ('BAT') tests were supervised by Gold Fields Group Services (PTY) Ltd ('Goldfields'). This program was completed in January 2011 and Goldfields confirmed that Dachang concentrate was ideally suited to the BIOX® process and that a BIOX® plant could be constructed to treat Dachang concentrate with a leach recovery of gold in solution of between 93.3 and 93.5% in the subsequent CIL plant.
In July of 2010 the Company also commissioned BGRIMM to carry out an ECT on a large sample of Dachang mineralization chosen to represent typical feed material for the Dachang mine operation. This sample totaled some 13 tonnes and graded approximately 3.05 gpt Gold, 5.32 gpt Silver and 0.48% Arsenic, and can be considered to be representative of mineralization at Dachang. BGRIMM established a pilot plant capable of treating 1 tonne of sample per day, using a conventional grinding and flotation circuit.
The ECT demonstrated that at a relatively coarse grind of 80% passing 106 microns, it was possible to produce two concentrate products from the Dachang bulk ore sample. These were a lower grade concentrate suitable for bacterial oxidation, grading 31.85 gpt gold with a recovery of 93.08%, and a higher grade concentrate suitable for sale to a smelter grading 60.27 gpt gold with a recovery of 92.3%. Concentrate from the lower grade bacterial oxidation run was subsequently shipped to SGS Laboratories in South Africa to conduct the commissioning of larger scale Batch Testwork to demonstrate the potential performance of a BIOX® plant for the oxidation and subsequent recovery of gold to dore. Goldfields supervised and evaluated the BAT and BIOX® testwork findings.
The Company now considers that the overall predictable recovery of gold from typical Dachang mineralization can be estimated to be 87.8% to dore, made up of flotation recoveries of 94.9%; BIOX®/CIL recoveries of 93.4% and estimated gold room recoveries of 99.0%. This exceeds the previously estimated overall gold recovery figures of 85.0% used in the Company's 2009 PEA. In addition, the comprehensive testwork program confirms that the effective grind size for the Dachang project can be coarsened from a P80 of 75 microns to a P80 of 106 microns, representing a significant saving in grinding costs, and potential increase in throughput for the project, for the same installed grinding power.
Gary A. Patrick, B.Sc., MAusIMM, has reviewed and approved the contents of this release. He acted as the Independent Expert retained by the Company to supervise the testwork program overall and is a Qualified Person under the definitions of National Instrument 43-101.
On Behalf of the Board:
James J. Moore, President & CEO
ABOUT INTER-CITIC:
Toronto-based Inter-Citic Minerals Inc. is an exploration and development company advancing its Dachang Gold Project in the People's Republic of China. Inter-Citic is listed on the TSX under the symbol ICI. Inter-Citic's website is www.inter-citic.com.
Investors are encouraged to review 'Risk Factors' associated with the Dachang project as outlined in the Company's 2010 Financial Statements and Annual Information Form, along with updates, available on the SEDAR website at www.sedar.com. The statements herein that are not historical facts are forward-looking statements. These statements address future events and conditions and so involve inherent risks and uncertainties, as disclosed under the heading 'Risk Factors' in the company's periodic filings with Canadian securities regulators. Actual results could differ from those currently projected. The Company does not assume the obligation to update any forward-looking statement.
The TSX has not reviewed and does not accept responsibility for the adequacy or accuracy of the content of this news release.
Contacts:
Inter-Citic Minerals Inc.
Stephen Lautens
Vice President, Corporate Communications
(905) 479-5072 x 227
stephen@inter-citic.com