Imperial Metals Corporation
TSX : III

Imperial Metals Corporation

May 03, 2010 09:30 ET

Imperial Metals Corporation: Red Chris Mineral Resource Increased and Metallurgy Improved

VANCOUVER, BRITISH COLUMBIA--(Marketwire - May 3, 2010) - Imperial Metals Corporation (TSX:III). A recently completed mineral resource estimate taking into account the 22 holes drilled by Imperial since its acquisition of the Red Chris copper/gold project in northwest British Columbia has added 1.29 billion pounds copper and 2.73 million ounces gold to measured and indicated resources, and 1.37 billion pounds copper and 2.54 million ounces gold to the inferred resources, at a 0.3% copper cut-off grade. Metallurgical testwork has confirmed improved metal recoveries at depth from the higher gold and copper grades found there.

At the 0.3% copper cut-off grade used for comparative purposes, the revised resource estimate represents a 31% tonnage increase in the measured and indicated category and an 89% tonnage increase in the inferred category over the previous 2005 resource estimate. The copper and gold grades in the measured and indicated category at the 0.3% copper cut-off grade are also significantly higher, with copper grades increasing from 0.46% to 0.54%, and gold grades increasing from 0.37 to 0.55 grams per tonne.

The higher grades discovered in the deeper drilling of the East zone have yielded an even more dramatic increase in the resource at higher cut-off grades. The measured and indicated resource at a 0.6% copper cut-off grade increased from 35.1 million tonnes grading 0.82% copper and 0.72 g/t gold to 86.96 million tonnes grading 0.88% copper and 1.11 g/t gold, representing a 148% increase in tonnage, a 7% increase in copper grade and a 55% increase in gold grade. The key metal and mineralogy changes observed at depth are increased gold and copper grades, increased the gold to copper ratio, increased distribution and occurrence of bornite, and reduced pyrite content.

Diamond drilling carried out by Imperial since acquiring the project in 2007 has extended the higher grade East zone to a depth of approximately one kilometre, more than double the depth of past drilling. This drilling has substantially increased the amount of contained metal, confirming more drilling is required to upgrade inferred resources to measured and indicated, and to further test the extent of the deposit at depth. Exploration drilling is underway with three drills and a fourth rig being mobilized to the site.

The estimate was prepared internally by Art Frye, Mine Operations Manager for the Mount Polley mine, and by Greg Gillstrom P.Eng, Senior Geological Engineer with Imperial Metals Corporation, who is designated as the "Qualified Person" as defined under 43-101 for the resource calculation. Mr. Gillstrom and Mr. Frye have reviewed the contents of this release. A technical report providing details of the estimate will be filed on SEDAR (www.sedar.com) within 30 days.

Imperial is preparing an update of the 2005 Feasibility Study for the development of the Red Chris project. The Company has initiated the project Mines Act permitting for the development of Red Chris with the Northwest Mine Development Review Committee ("NWMDRC") Northwest Mine Development.

Mineral resources are reported at various cut-off grades as presented in the following table.

RED CHRIS DEPOSIT MINERAL RESOURCES - MAY 2010

  MEASURED + INDICATED MINERAL RESOURCES   INFERRED MINERAL RESOURCES  
Cut-off Tonnes Cu  Au  CuEq  Lbs Cu Oz Gold Tonnes Cu  Au CuEq  Lbs Cu Oz Gold
Cu% X 1,000 % g/t % X 1,000 x 1,000 X 1,000 % g/t % X 1,000 X 1,000
>=0.10 619,417 0.38 0.36 0.534 5,139,790 7,162 619,129 0.30 0.32 0.443 4,120,730 6,429
>=0.20 489,151 0.43 0.42 0.618 4,674,389 6,634 437,939 0.36 0.39 0.531 3,497,936 5,433
>=0.30 312,571 0.54 0.55 0.781 3,710,414 5,564 237,701 0.46 0.50 0.675 2,396,943 3,794
>=0.40 189,526 0.66 0.74 0.986 2,775,182 4,484 105,613 0.60 0.69 0.901 1,398,864 2,332
>=0.50 125,310 0.78 0.93 1.182 2,147,043 3,728 60,326 0.72 0.87 1.101 957,825 1,687
>=0.60 86,957 0.88 1.11 1.367 1,685,773 3,115 39,197 0.81 1.02 1.257 702,112 1,282
>=0.70 57,585 1.00 1.34 1.584 1,267,272 2,479 22,470 0.94 1.19 1.460 464,170 863
>=0.80 39,207 1.12 1.56 1.798 965,359 1,961 14,317 1.05 1.37 1.648 331,485 629
>=0.90 27,299 1.24 1.78 2.013 744,212 1,558 8,814 1.18 1.56 1.859 228,447 442
>=1.00 20,083 1.34 1.96 2.199 593,780 1,266 6,388 1.26 1.69 2.002 177,860 347
>=1.10 15,633 1.42 2.08 2.334 491,073 1,045 4,561 1.35 1.79 2.137 135,958 263
>=1.20 12,072 1.51 2.21 2.474 401,064 858 3,814 1.39 1.84 2.195 116,922 225
>=1.30 8,973 1.60 2.39 2.644 316,025 690 2,387 1.47 1.92 2.312 77,533 147
>=1.40 6,568 1.69 2.51 2.787 244,377 531 1,393 1.56 1.95 2.418 48,047 87
>=1.50 4,806 1.78 2.69 2.951 188,175 415 796 1.65 2.02 2.535 28,948 52
           
  MEASURED MINERAL RESOURCES INDICATED MINERAL RESOURCES
Cut-off Tonnes Cu Au CuEq Lbs Cu Oz Gold Tonnes Cu Au CuEq Lbs Cu Oz Gold
Cu% X 1,000 % g/t % X 1,000 X 1,000 X 1,000 % g/t % X 1,000 X 1,000
>=0.10 534,267 0.38 0.37 0.544 4,514,679 6,311 85,150 0.33 0.31 0.469 625,112 851
>=0.20 424,693 0.44 0.43 0.628 4,124,308 5,863 64,458 0.39 0.37 0.550 550,081 771
>=0.30 277,190 0.54 0.56 0.787 3,318,846 4,962 35,381 0.50 0.53 0.733 391,568 602
>=0.40 171,002 0.67 0.73 0.986 2,510,390 4,023 18,524 0.65 0.77 0.987 264,792 461
>=0.50 113,545 0.78 0.92 1.180 1,948,007 3,350 11,765 0.77 1.00 1.204 199,036 377
>=0.60 78,659 0.88 1.11 1.366 1,528,268 2,800 8,299 0.86 1.18 1.377 157,505 315
>=0.70 52,028 1.00 1.34 1.586 1,148,837 2,234 5,558 0.97 1.37 1.568 118,435 246
>=0.80 35,491 1.12 1.55 1.801 877,028 1,773 3,716 1.08 1.58 1.769 88,331 188
>=0.90 24,663 1.24 1.78 2.022 675,946 1,411 2,637 1.17 1.74 1.934 68,266 147
>=1.00 18,242 1.35 1.97 2.210 542,129 1,156 1,841 1.27 1.86 2.088 51,651 110
>=1.10 14,224 1.43 2.09 2.349 449,268 958 1,409 1.35 1.93 2.188 41,806 87
>=1.20 11,012 1.52 2.23 2.493 368,075 791 1,060 1.41 1.98 2.276 32,989 67
>=1.30 8,144 1.61 2.43 2.674 289,485 635 828 1.45 2.05 2.350 26,540 55
>=1.40 6,038 1.70 2.54 2.816 226,697 494 530 1.51 2.15 2.455 17,680 37
>=1.50 4,558 1.79 2.71 2.973 179,436 398 248 1.60 2.20 2.558 8,740 18
A copper only cut-off was used in this study to match the historic study; future studies will use a CuEq (copper equivalency) cut-off. The copper equivalent column on the resource table was calculated using prices of copper ($3.00/lb) and gold ($900/oz) and not including any metallurgical parameters to show a copper equivalent value for the resource.

At year end 2009, two composite samples of deep East zone mineralization were submitted to G&T Metallurgical Services for testing to assess the mineralogical and metallurgical response of deeper East zone mineralization. The testwork conformed to the previously developed process for treating Red Chris ores. The two samples were derived from recent drilling. The first, "High Au to Cu" was made up from high gold to copper ratio intervals and the second, "High Bornite" was from intervals with a high percentage bornite (a copper sulphide mineral that is 66% copper). Both samples had high values of copper and gold and relatively low ratios of pyrite to copper sulphides compared to previously tested East zone samples.

The High Au to Cu East zone composite exhibited almost perfect copper metallurgical performance with 97-98% recovered into rougher concentrate, along with 91-93% of the gold. Both copper and gold rougher flotation performances were well above average for deposits of this type. Overall the results, including cleaning, were remarkably high with 96% of the copper recovered into a concentrate grading about 33% copper. Similarly, 88% of the gold was recovered into the copper concentrate grading about 50 grams per tonne gold.

The High Bornite flotation testing resulted in recoveries of 93-95% copper and an average of 88% gold into the rougher concentrate. After cleaning the rougher concentrates about 90% of the copper in the feed was recovered into a concentrate grading about 45% copper. Gold performance following cleaning was variable, but on average about 75% of the gold was recovered into the copper concentrate grading about 60 grams per tonne gold.

The observed performance was superior to results achieved on previously tested East zone samples. The excellent response of these composite samples is attributable to the higher grade of copper and gold, lower pyrite content and more favorable fragmentation properties. The testwork employed the previously developed Red Chris flowsheet, designed for lower grade ores containing considerably more pyrite. The flowsheet could likely be optimized to reduce operating costs when treating mineralization similar to the composites tested in this program. Adopting coarser primary and regrinding sizes, and lower pulp pH could reduce costs, with negligible effect on metallurgical performance.

The Red Chris project is located in northwest British Columbia, and lies at an elevation of 1,500 metres above sea-level on a plateau with topography and climate favorable to mining operations. Red Chris is 310 kilometres from tidewater at the port of Stewart. Access to the property from pavement at Highway 37 is six kilometres along the Ealue Lake Road, and 17 kilometres along the Red Chris access trail.

Contact Information

  • Imperial Metals Corporation
    Brian Kynoch
    President
    604.669.8959
    or
    Imperial Metals Corporation
    Patrick McAndless
    Vice President Exploration
    604.488.2665
    or
    Imperial Metals Corporation
    Sabine Goetz
    Investor Relations
    604.488.2657
    info@imperialmetals.com
    www.imperialmetals.com