VANCOUVER, BRITISH COLUMBIA--(Marketwire - April 24, 2012) -Colombian Mines Corporation (TSX VENTURE:CMJ)(FRANKFURT:X6C) ("Colombian Mines" or "the Company") announces recoveries of 96.4% of the contained gold, 97.8% of copper, 91.1% of silver and 96.8% of the zinc in metallurgical tests on mineralization from the Sabana Blanca zone at El Dovio. McClelland Laboratories, Inc. of Reno, Nevada supervised and conducted the tests using conventional milling and froth flotation techniques. Mr. Gene McClelland, a well known, highly respected metallurgist and principal of McClelland Laboratories stated that in "more than 38 years of experience, the El Dovio mineralization is some of the most responsive to flotation recovery that I have ever seen".
Using what Management believes to fairly represent average grade mineralization, flotation tests were conducted on a bulk composite sample with an average grade of 5.3 grams per tonne gold (g/T Au), 4.7 grams per tonne silver (g/T Ag), 0.86% Copper (Cu) and 1.12% Zinc (Zn) from the Sabana Blanca tunnel at El Dovio. A map showing the Sabana Blanca tunnel and simplified project geology and geochemistry can be found at https://www.colombianmines.com/i/pdf/MMI_Geol_4-20-12_24X36.pdf. The sample was treated using standard froth flotation methods after stage crushing and grinding to 80% passing 75 microns (200 mesh), a prevalent grind size in modern mills, such as at Newmont's Yanacocha Mine in northern Peru where the mill produces approximately 650 tonnes per hour to 80% passing 75 microns.
The sample was selected to characterize mid to low grade, high sulfide, gold - copper mineralization typical of known mineralization at El Dovio. Samples of unoxidized, unweathered mineralization in the Sabana Blanca tunnel ranging from a depth of 3 to more than 30 meters vertically below the surface were specifically selected for the composite sample to more accurately represent the character of mineralization expected throughout the bulk of the system because heavily oxidized surface samples have potential to yield inaccurate and misleading metallurgical results in flotation tests.
Discussion of El Dovio:
The 10,000+ hectare, El Dovio project, widely considered to be one of the preeminent untested mineral prospects in Colombia, is a gold rich polymetallic system that also contains significant copper, zinc and silver mineralization. The Sabana Blanca zone, the principal known mineralized zone on the property at this time is hosted in brecciated and altered marine volcanic and intrusive rocks, and remains open to expansion in all directions. A Mobile Metal Ion (MMI) geochemical anomaly roughly 1 kilometer long is associated with the mineralization in the Sabana Blanca zone. Several other large geochemical anomalies, indicate additional exploration potential on the property. As shown on the Geochemistry and Geology Map which may be viewed at https://www.colombianmines.com/i/pdf/MMI_Geol_4-20-12_24X36.pdf, one of these anomalies corresponds well with a favorable geological contact between the marine volcanic rocks that host the Sabana Blanca zone and overlying marine sediments. Contacts such as this often host bedded Volcanogenic Massive Sulfide mineralization (VMS) as at the Mina El Roble approximately 110 kilometers to the northeast. The Company is currently pursuing these anomalies with a program of systematic diamond saw cut channel sampling to assess the potential for additional discoveries of mineralization on the property.
The flotation process is particularly effective on high sulfide ores such as El Dovio, and the excellent results reported herein are important and positive indications of recoveries, costs and economics for future resource estimates and production considerations. Management is very encouraged by this and other recent developments at El Dovio and continues to anticipate timely receipt of permits for drilling this summer.
Please refer to the Company's website for historical press releases and a more thorough discussion of the El Dovio property and the Company's other major properties in Colombia.
Upcoming Events:
The Company will co-host a "Colombia Day" Event in New York City on May 14th, 2012 - Presentations from 2:00 - 5:00 with a social gathering to follow. Space is limited; seriously interested parties only should contact Sharon Hebgin at (604) 649-9195 or by email at shebgin@colombianmines.com for information.
Mr. Robert G. Carrington, P. Geo, a Qualified Person as defined by National Instrument 43-101 and President of the Company, has reviewed and verified the technical information contained in this news release.