Thundermin Resources Inc.

Thundermin Resources Inc.

October 19, 2010 08:00 ET

Thundermin and Cornerstone Report Excellent Metallurgical Results from Scoping Level Test Work Undertaken on Core Samples from the Little Deer Copper Deposit

TORONTO, ONTARIO--(Marketwire - Oct. 19, 2010) - Thundermin Resources Inc. ("Thundermin") (TSX:THR) and 50% joint venture partner Cornerstone Resources Inc. ("Cornerstone") (TSX VENTURE:CGP) are pleased to announce that excellent metallurgical results have been obtained from scoping level test work undertaken on core samples from the Little Deer Copper Deposit ("Deposit") which is located approximately 10 km north of Springdale in north-central Newfoundland.


  • Production of a saleable, high grade copper concentrate grading over 28% copper with over 97% copper recovery in locked cycle tests
  • Copper concentrates free of any deleterious elements
  • Copper recovered employing a simple rougher-cleaner flowsheet using a common xanthate collector
  • Copper mineralization of medium hardness with Bond ball mill work index of 14.6 kilowatt hours per tonne ("kWh/t")
  • Fresh and aged tailings decant solutions well within Canadian Metal Mining Effluent Regulations ("MMER") limits and non-lethal designations for MMER aquatic toxicology tests

Work Summary

SGS Lakefield Research ("Lakefield") of Lakefield, Ontario, an ISO 17025:2005 accredited company, was retained by Thundermin and Cornerstone to undertake a scoping level metallurgical test program on copper mineralization from the Deposit accompanied by basic environmental characterization of the flotation tailings produced from the metallurgical test program.

The metallurgical test program consisted of two main components: 1) sample characterization including head sample chemical analysis, quantitative evaluation of materials by QEMSCAN™ analysis, and Bond ball mill grindability tests; and 2) flotation testing including rougher and cleaner testing, locked cycle testing and detailed concentrate chemical analysis. The environmental test program consisted of: 1) inductively coupled plasma-optical emission spectroscopy/mass spectroscopy ("ICP-OES/MS") elemental analysis; 2) shake flask extraction ("SFE") testing; 3) modified acid base accounting ("ABA"); 4) net acid generation ("NAG") testing; 5) ICP-OES/MS analysis of the fresh and aged tailings decant solutions; and 6) single concentration acute lethality testing of effluent on MMER aquatic test species (Daphnia Magna and Rainbow Trout).

Sample Preparation and Head Grade

Approximately 200 kilograms ("kg") of crushed reject core sample was shipped to Lakefield in plastic pails. This sample was selected from six drill holes located throughout the Deposit and was designed to approximate, as closely as possible, the anticipated average copper grade for the Deposit. At Lakefield, the sample was combined and blended into one 200 kg composite sample. Ninety (90) kg was riffle split from this sample for metallurgical testing and the remainder was stored in a freezer. Ten (10) kg of the sample was riffled out for a Bond ball mill work index hardness test. The remaining 80 kg was stage- crushed to -10 mesh and rotary split into 2 kg test charges for flotation testing. All materials were stored frozen until subjected to testing.

A 2 kg test charge sample was submitted for a range of chemical analysis. The head grade of the sample was 2.43% copper, 0.034% cobalt, 0.03 g/t Au, 19.1% iron and 5.99% sulphur.

Grindability Test Results

A standard Bond ball mill grindability test was completed at a closing sieve size of 80 mesh. The Bond mill work index was measured at 14.6 kWh/t which is considered to be of medium hardness based on Lakefield's extensive work index database.

Flotation Test Results

Flotation test results revealed that the copper mineralization at Little Deer can be recovered easily using a simple rougher-cleaner flowsheet with a common xanthate collector at a pH of 9 using lime as the modifier. An analysis of the liberation characteristics of the chalcopyrite determined that the primary grind needs to be in the range of 80% passing 150 microns, with a regrind in the range of 80% passing 30- 40 microns likely necessary.

Results of two locked cycle tests completed on samples of the Little Deer copper mineralization are presented below in Table 1. Test LCT-1 differed from LCT-2 mainly with respect to primary grind size, with LCT-1 completed at a primary grind P80 of 160 um versus LCT-2, which was at a P80 of 100 um. Both tests achieved approximately 97% copper recovery into a saleable concentrate grading 28% copper.

Table 1. Locked Cycle Test Results
        Assays Distribution
Product  Weight
% Cu % S % Co % Cu % S % Co
LCT-1 1°- 162um Cu 3rd Cleaner Conc 8.3 28.0 34.3 0.065 96.7 49.0 20.8
  2°- 34um Cu 1st Cl Scav Tail 11.6 0.28 14.2 0.078 1.4 28.1 34.9
    Cu Rougher Tail 80.1 0.059 1.67 0.014 2.0 22.9 44.3
    Head (calc.) 100.0 2.41 5.82 0.026 100.0 100.0 100.0
LCT-2 1°- 96um Cu 3rd Cleaner Conc 8.2 28.3 34.4 0.061 97.2 48.9 17.0
  2°- 32um Cu 1st Cl Scav Tail 10.6 0.33 16.0 0.107 1.5 29.3 38.7
    Cu Rougher Tail 81.1 0.038 1.56 0.016 1.3 21.8 44.2
    Head (calc.) 100.0 2.40 5.80 0.029 100.0 100.0 100.0

Environmental Test Results

The purpose of the environmental test program was to assess the geochemical, acid rock drainage ("ARD"), aquatic toxicology and contaminant mobility potential associated with the Little Deer flotation tailings materials over time. The ICP-OES/MS strong acid digest elemental analysis indicated that the tailings sample was predominantly comprised of silica and iron with moderate to minor amounts of alumina, magnesium and calcium. Analysis of the shake flask extraction leachate reported a slightly alkaline final pH value and all MMER controlled parameters at concentrations well within the designated limits. ABA indicated that the tailings sample was potentially acid generating and NAG testing confirmed the acid generating nature of the tailings sample. Analysis of the fresh and aged tailings decant solutions reported all controlled parameters at concentrations well within MMER limits and acute lethality testing of the Decant Day 28 solution resulted in non-lethal designations for both Daphnia Magna and Rainbow Trout.


The results of a scoping level metallurgical test program on a representative composite sample of copper mineralization from the Deposit indicate that a saleable, high grade concentrate grading 28% copper can be achieved with approximately 97% copper recovery.

The use of a simple rougher-cleaner flowsheet, a common xanthate collector, pH control with lime and a relatively course primary grind for copper liberation from mineralization of medium hardness suggest that the operating costs should fall into the low range for any metallurgical plant constructed to treat the Little Deer mineralization.

Mineral Resource Estimate

On October 13, 2010, Thundermin and Cornerstone reported an updated National Instrument 43-101 ("NI 43-101") mineral resource estimate for the Deposit comprising Indicated Mineral Resources of 1,150,500 tonnes at an average grade of 2.8% Cu within the Little Deer Zone and Inferred Mineral Resources of 2,355,500 tonnes at an average grade of 2.1% Cu within the Little Deer and Footwall Zones (see news release dated October 13, 2010).

Based on diamond drilling results to date, the Deposit is interpreted to consist of two main copper-bearing zones, the Little Deer Zone and the Footwall Zone with the Footwall Zone occurring mainly west of, and from 50 to 75 m below, the Little Deer Zone. A number of additional copper-bearing zones have also been intersected in the footwall of these two zones, but their extent and significance are unknown at the present time. The Deposit has been intersected over a strike length of approximately 1,050 m and to a vertical depth of approximately 1,000 m. The overall Deposit remains open along strike to the east and west, up dip and at depth and the potential exists for the discovery of additional mineral resources in all areas.

Little Deer Joint Venture

Thundermin, the operator, and Cornerstone have the option, on a 50/50 basis to earn a 100% interest in the Deposit and adjacent property from Weyburn Investments Ltd. Thundermin, under its joint venture agreement with Cornerstone, has the right to increase its interest in the Little Deer property to 75% by completing a feasibility study and by arranging 100% of the necessary bank financing required to place the property into commercial production. Details on the Deposit and the terms of the agreement with Weyburn can be found in numerous news releases and on Thundermin's and Cornerstone's respective websites and on SEDAR.

Qualified Persons

Mr. Dan Imeson, M.Sc., Manager, Mineral Processing for Lakefield supervised the metallurgical test program on the Little Deer copper mineralization and Ms. Barbara A. Bowman, Senior Technologist, Environmental Testing and Mr. Robert J. Caldwell, Group Leader, Environmental Testing for Lakefield supervised the basic environmental characterization of the flotation tailings produced during the scoping level flotation testing of the Little Deer copper mineralization. Mr. Imeson, Ms. Bowman and Mr. Caldwell have all reviewed the contents of this news release for accuracy with respect to the metallurgical work done at Lakefield. Mr. Klaus Konigsmann, P. Eng., Thundermin's and Cornerstone's metallurgical consultant and independent Qualified Person ("Q.P.") in accordance with NI 43-101, has also reviewed the contents of this news release for accuracy with respect to the metallurgical work done at Lakefield. The mineral resource estimate for the Deposit was prepared by Mr. Reno Pressacco, M.Sc.(A), P.Geo., Senior Geologist for Scott Wilson Roscoe Postle Associates Inc. of Toronto, Ontario, an independent Q.P. in accordance with NI 43-101. Mr. Pressacco has reviewed the contents of this release for accuracy with respect to the mineral resource estimate.

About Thundermin

Thundermin is a Canadian-based mineral exploration company focused on the exploration for and the discovery of economically viable base metal and gold deposits in Canada. Thundermin has an interest in, or the right to earn an interest in 11 base metal and gold properties in Canada. Thundermin also has royalty interests in a further 28 base metal and gold properties located in Manitoba, Saskatchewan, British Columbia and Quebec, the most significant being a 2.5% net smelter return royalty in the Pelletier Lake gold deposit upon which Alexis Minerals Corporation has just released a positive feasibility study. Thundermin also has various shareholdings in thirteen other junior resource companies that are actively exploring for base metal, gold, chrome, vanadium-titanium and diamond deposits in Canada.

Forward-Looking Statements

This news release may contain "Forward-Looking Statements" that involve risks and uncertainties, such as statements of Thundermin's plans, objectives, strategies, intentions and expectations. The words "potential," "anticipate," "forecast," "believe," "estimate," "expect," "may," "project," "plan," and similar expressions are intended to be among the statements that identify "Forward-Looking Statements". Although Thundermin believes that its expectations reflected in these "Forward- Looking Statements" are reasonable, such statements may involve unknown risks, uncertainties and other factors disclosed in our regulatory filings that can be viewed on the SEDAR website at For us, uncertainties arise from the behavior of financial and metals markets and from numerous other matters of national, regional, and global scale, including those of an environmental, climatic, natural, political, economic, business, competitive, or regulatory nature. These uncertainties may cause our actual future results to be materially different than those expressed in our "Forward-Looking Statements". Although Thundermin believes the facts and information contained in this news release to be as correct and current as possible, Thundermin does not warrant or make any representation as to the accuracy, validity or completeness of any facts or information contained herein and these statements should not be relied upon as representing its views subsequent to the date of this news release.

For further information on Thundermin Resources Inc. please visit Thundermin's website at or the SEDAR website at

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