TORONTO, ONTARIO--(Marketwire - July 20, 2009) - Adex Mining Inc. ("Adex" or the "Company") (TSX VENTURE:ADE) is pleased to provide a progress report on metallurgical test programs that were carried out by the Company in relation to its Mount Pleasant Mine Property ("Mount Pleasant" or the "Property"). The results of the metallurgical test programs provide the Company with valuable information required to develop an optimal commercial extraction and recovery process for the principal metals hosted at Mount Pleasant, being tungsten, molybdenum, tin and indium. This information will also help guide the Company in developing production options for the Property.
GRAVITY-FLOTATION SEPARATION TEST PROGRAM
SGS Lakefield Research Europe Ltd. of Cornwall, United Kingdom ("SGS Europe") has completed initial bench scale testing of a multi-stage grinding and gravity-flotation separation process (the "Gravity Process"). The Gravity Process is being considered by the Company as an innovative approach to improving the grade and recovery (by pre-concentration) of the metals hosted at Mount Pleasant's two mineralized zones - being the tungsten-molybdenum bearing Fire Tower Zone (the "FTZ") and the tin-indium-zinc bearing North Zone (the "NZ").
The Gravity process was designed by Thibault & Associates Inc. of Fredericton, New Brunswick and was tested using bench scale techniques by SGS Europe to quantify its metallurgical performance for the production of tungsten concentrate from the FTZ deposit. The Company is evaluating the use of tungsten concentrate from the Gravity Process and a hydrometallurgical Process for possible production of ammonium paratungstate ("APT"). APT is considered the primary intermediate for the production of tungsten carbide which is used primarily for hard steel applications.
The Gravity Process was bench scale tested for conceptual design of the concentrator. The results of the bench scale test were also used to model the performance of the proposed flowsheet. Bench scale batch test results combined with computer modeling of a fully integrated flowsheet for continuous concentrate production has indicated that a recovery of 83.3% for tungsten with a concentrate grade of 25.6% tungsten tri-oxide (WO3) may be achieved. A continuous pilot test of the proposed Gravity Process will be required to verify the overall grade and recovery of processing the ore from the FTZ.
The Gravity Process tested on ore samples from the FTZ was also used to assess tin concentrate production from the NZ deposit. The results of the Gravity Process test program indicate that modifications to the flowsheet developed for tungsten production will be required for the production of tin concentrate.
TUNGSTEN GRAVITY CONCENTRATE LEACHING TEST PROGRAM
Development of the Gravity Process: a representative sample of ore from the FTZ zone was processed by the Minerals Engineering Centre of Dalhousie University in Halifax, Nova Scotia to produce a low grade tungsten concentrate.
Research and Productivity Council ("RPC") of Fredericton, New Brunswick then completed a bench scale test program to improve on the quality of the gravity concentrate for APT production. Bench scale flotation tests on the low grade gravity concentrate achieved up to 70% reduction of the arsenic bearing minerals prior to tungsten leaching, thereby improving feedstock for APT production.
The tungsten leach is the initial step of the APT hydrometallurgical process developed by Thibault & Associates Inc. and the test program was conducted by RPC to assess the technical viability of the proposed leaching process. Two stage atmospheric bake-leach and single stage autoclave leach tests were carried out on the arsenic (arsenopyrite, loellingite) flotation tails (tungsten concentrate) to assess processing alternatives for the extraction of tungsten from low grade concentrates. The results of the leach test program indicate a selective process for optimum tungsten extraction (using an autoclave leach) in the range of 95% to 99% may be achieved based on bench scale batch testing.
The arsenic flotation and tungsten leach tests will assist the Company in the design of a hydrometallurgical process for the production of APT from a gravity concentrate. Continuous piloting of the leach and solution purification unit operations will be required to confirm the purity of the APT.
MINERALOGY ASSESSMENT PROGRAM
SGS Lakefield Research Limited of Lakefield, Ontario ("SGS Lakefield") has completed a detailed mineralogy assessment (the "Mineralogy Assessment") of ore from both the FTZ and NZ. The initial results of the Mineralogy Assessment, which were first reported in the Company's press release dated December 23, 2008, provide information on grain size for various minerals, liberation or grind requirement and theoretical grade-recovery relationships for the beneficiation of various metals. The results of the Mineralogy Assessment also suggest that sphalerite is the predominant host of indium at Mount Pleasant.
The foregoing series of metallurgical programs that have been completed by the Company at its contract laboratory facilities, being SGS Lakefield, SGS Europe, Dalhousie University and RPC, were necessary in order for the Company to move forward in developing various production options for the Property. In addition, the information obtained from the metallurgical programs will assist the Company in designing and developing a future pilot plant program which may lead to commercial-level production of tungsten, molybdenum, tin and indium at Mount Pleasant.
SGS Lakefield and SGS Europe are leading mineralogy research and metallurgical testing firms. RPC is an independent R&D firm situated in Fredericton, New Brunswick. Thibault & Associates Inc. - Applied Process Chemical Engineering of Fredericton, New Brunswick serves as an independent consulting firm to the Company with respect to Mount Pleasant metallurgical and environmental process development, design and planning.
Mr. J. Dean Thibault, M.Sc., P. Eng., is the Senior Process Chemical Engineer of Thibault & Associates Inc., and is an independent qualified person as defined by National Instrument 43-101. Mr. Thibault has managed the metallurgical test programs and supervised the preparation of the technical information contained in this press release in compliance with National Instrument 43-101.
Adex Mining Inc. is a Canadian junior mining company with an experienced management team. The Company is focused on developing its flagship Mount Pleasant Mine Property, a multi-metal project that is host to promising tungsten-molybdenum and tin-indium-zinc-copper mineralization. Located in Charlotte County, New Brunswick, Mount Pleasant is situated approximately 80 kilometres south of Fredericton, the provincial capital, and is 65 kilometres from the United States border. The common shares of Adex trade on the TSX Venture Exchange under the stock symbol "ADE".
Certain statements in this press release may constitute "forward-looking" statements which involve known and unknown risks, uncertainties and other factors which may cause actual results, performance or achievements of Adex, its subsidiary or the industry in which they operate to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. When used in this press release, the words "estimate", "believe", "anticipate", "intend", "expect", "plan", "may", "should", "will", the negative thereof or other variations thereon or comparable terminology are intended to identify forward-looking statements. Such statements reflect the current expectations of the management of Adex with respect to future events based on currently available information and are subject to risks and uncertainties that could cause actual results, performance or achievements to differ materially from those expressed or implied by those forward-looking statements. These risks and uncertainties are detailed from time to time, including, without limitation, under the heading "Risk Factors", in reports filed by Adex with the Alberta, British Columbia and Ontario Securities Commissions which are available at www.sedar.com and to which readers of this press release are referred for additional information concerning Adex, its prospects and the risks and uncertainties relating to Adex and its prospects. New risk factors may arise from time to time and it is not possible for management to predict all of those risk factors or the extent to which any factor or combination of factors may cause actual results, performance and achievements of Adex to be materially different from those contained in forward-looking statements. Although the forward-looking statements contained in this press release are based upon what management believes to be reasonable assumptions, Adex cannot assure investors that actual results will be consistent with these forward-looking statements. Given these risks and uncertainties, investors should not place undue reliance on forward-looking statements as a prediction of actual results.
The forward-looking information contained in this press release is current only as of the date of the press release. Adex does not undertake or assume any obligation to release publicly any revisions to these forward-looking statements to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events, except as required by law.
No securities commission or regulatory authority has approved or disapproved the contents of this press release.
FOR FURTHER INFORMATION PLEASE CONTACT:
Adex Mining Inc.
J. Errol Farr, CMA
President, Chief Executive Officer and Director