DNI METALS INC. (DNI : TSX-Ven)(DG7 : Frankfurt)
TORONTO, Feb. 27, 2012 /CNW/ - DNI Metals Inc. (DNI:TSX-Ven)(DG7:FSE) is pleased to announce additional initial results from its bioleaching testwork on drill core samples from the Buckton inferred resource (announced Oct24/2011 and Jan16/2012) at its polymetallic black shale projects, Athabasca Region, Alberta. The current results reinforce conclusions from previous testwork announced on September 8, 2011, and reiterate recoveries for Mo-Ni-U-V-Zn-Cu-Co-Li. The leaching tests also enable calculation of initial recoveries for Specialty Metals and Rare Earth Elements (REE) which are incidentally recovered as co-products during leaching.
The results being reported are from recently completed bench scale batch amenability bioleaching testwork launched in 2011, carried out by the Alberta Innovates Technology Futures (AITF, formerly the Alberta Research Council), using 200gm samples which were tested in duplicate to specifications formulated by DNI.
A summary of the best metal recoveries achieved during the above bioleaching tests, as reported by AITF, are as follows: Mo-41%, Ni-89%, U-92%, V-24%, Zn-93%, Cu-78%, Co-94%, Li-29%. The results are consistent with results previously reported by AITF whose work focused on Mo-Ni-U-V-Zn-Cu-Co-Li only.
Recoveries for Specialty Metals and REE incidentally leached as co-products during the testwork, as calculated by DNI based on the difference of metal content between head sample feed material and final tail residues per analytical results from AITF's testwork, are as follows: La-39%, Ce-47%, Pr-61%, Nd-66%, Sm-76%, Eu-79%, Gd-83%, Tb-88%, Dy-84%, Ho-86%, Er-82%, Tm-73%, Yb-75%, Lu-73%, Y-85%, Th-60%, Sc-31%.
The above results are from bioleaching of composite drill core samples representing three complete drill intercepts across the entire thickness of the Second White Speckled Shale Buckton polymetallic zone. The three holes (holes 11BK01, 11BK02 and 11BK04) were drilled by DNI during the 2010-2011 winter drill program.
While prior testwork (announced September 8, 2011) had been on select material from surface trench sampling representative of the zone, corroboration of prior results with data from leaching of fresh composite drill core samples reinforces prior leaching results.
All of the above results were achieved under test conditions which are yet to be optimized and, as such, are regarded by DNI as initial results which future work will endeavor to improve by further optimizing and refining test parameters.
One of the duplicate samples was further leached in HCl following bioleaching to monitor precipitation of a variety of compounds (eg: jarosites, sulfates, ferro-compounds) and to assess related metals re-precipitation from the leaching solution after the metals had been extracted from the shale. As previously observed in prior bioleaching tests conducted at AITF, the test results indicate that while a small fraction of all dissolved metals, once leached from the shale, are removed from the leaching solution through re-precipitation, a considerable portion of Mo-V-Cu once leached from the shale are lost to re-precipitation. Mitigation of these processes will be addressed during future testwork intended to optimize test parameters to enhance recoveries of Mo-V-Cu.
Plans are underway for an expanded leaching testwork program to start in the summer to commence testing progressively larger samples and to formulate procedures for separation of the various metals into final products including separation of Specialty Metals and REE from leaching solutions once they have been extracted from the shale.
In addition to testing samples from the Buckton polymetallic inferred resource, a representative drill core sample of the overburden material (LaBiche Shale) overlying the Buckton resource was also leached and reported very encouraging recoveries for Base Metals, Specialty Metals and Rare Earth Elements. Details of metal recoveries from leaching of the overburden cover material, previously regarded to be "waste" material, will be announced shortly.
The Qualified Person in connection with this press release is S.F.Sabag P.Geo, DNI's president and CEO, who has reviewed analytical results and is responsible for preparation of this press release. See DNI press Sep8/2011 and Alberta Mineral Assessment Report MIN20100017 for considerable details of procedures related to the bioleaching testwork. Bioleaching was carried out using inoculum previously harvested and cultured by AITF from DNI's black shale zones. Analytical work carried out by Actlabs, Ancaster, Ontario, by ICP-MS. The Buckton inferred resource was announced Oct24/2011 and Jan16/2012, and technical reports related thereto are available from www.sedar.com and www.dnimetals.com.
Neither the 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.
DNI - TSX Venture
DG7 - Frankfurt
We seek Safe Harbour. This announcement includes forward looking statements. While these statements represent DNI's best current judgment, they are subject to risks and uncertainties that could cause actual results to vary, including risk factors listed in DNI's Annual Information Form and its MD&As, all of which are available from SEDAR and on its website.
For further information: