ANDINA Minerals Inc.

ANDINA Minerals Inc.

November 21, 2007 18:05 ET

ANDINA Reports Positive Metallurgical Results From Volcan Project

TORONTO, ONTARIO--(Marketwire - Nov. 21, 2007) - ANDINA Minerals Inc. (TSX VENTURE:ADM) ("Andina") is pleased to report positive preliminary metallurgical test results from sulphide-bearing gold mineralization from its 100%-owned Volcan Gold Project which is the focus of a ongoing 50,000-metre drill program. The Volcan property hosts a measured and indicated resource of 2.93 million ounces of gold (115.1 million tonnes grading 0.79 grams per tonne gold ("g/t Au")) and an inferred resource of 4.20 million ounces of gold (170.3 million tonnes grading 0.77 g/t Au) at a 0.5 g/t Au cut-off (Andina October 22, 2007 press release).

Gold recoveries from four column tests of Dorado West Zone deposit mineralization ranged from 57% to 77% with increasing recoveries directly correlated with increased gold grades (see table 1). The column tests, conducted by McClelland Laboratories, Inc., Nevada, ("McClelland") were run for 64 days with the recoveries showing a break out around four (4) days and extraction generally levelling out after 26 days indicating very fast leach kinetics likely due the high purity (approximately 98%) and small grain size of the gold.

Four 96-hour bottle roll tests, completed by McClelland on the same composite samples, returned slightly lower gold recoveries ranging from 51% to 71%. Advanced Mineral Technology Laboratory (AMTEL), London, Ontario conducted 48-hour bottle roll tests on the same composite samples achieving gold recoveries ranging from 54% to 78% inline with the column test results. Both set of bottle roll tests displayed a positive correlation between increased recoveries and increased gold grades.

Table 1 - Volcan Gold Project Metallurgical Test Results, November 2007

Test Gold Recoveries Reagents Consumed(1)
Calculated ------------------------------------------ Bond Work
Gold Grade Bottle Roll Column NaCN(2) Cement Index
(g/t Au) (%) (%) kg/t kg/t (kWh/t)
C 0.45 51 57 1.24 4.0 11.6
B 0.65 60 64 2.51 8.0
D 0.90 70 70 1.38 3.0 12.3
E 1.17 71 77 1.50 6.0 13.4
1. Reagents consumed during column tests
2. sodium cyanide

"We are quite pleased with the results achieved from the preliminary metallurgical testwork", said Carl B. Hansen, President and CEO of Andina "as they confirm that the Volcan gold mineralization may be amenable to heap leaching. Recoveries were as expected for the mid-range grades and were better than anticipated at the both lower and higher-grade ranges. The quick rate of gold extraction combined with low cyanide and cement consumption further demonstrates the potential of the Volcan gold deposits. In addition to the ongoing 50,000-metre drilling program, further metallurgical test work is continuing.

Metallurgical Test Details

The tested composite samples, collected from quartered HQ drill core, were selected to represent a range of gold grades from low grade gold mineralization collected from the edge of Dorado West Zone deposit (sample C) to higher grade mineralization from the central portion of the deposit (samples D and E). Sample B is a composite of gold mineralization, collected and prepared in late 2006, from throughout the Dorado West Zone deposit.

The sample material, approximately 600 kilograms, was sent to KHD Humboldt Wedag GmbH, Cologne where it was crushed to 2.6 mm with a high-pressure grinding roll (HPGR). The bottle and column tests were conducted by McClelland Laboratories, Inc. of Sparks, Nevada, a metallurgical and engineering firm recognized as a leading expert in gold and silver heap leach metallurgy. Advanced Mineral Technology Laboratory (AMTEL), London, Ontario is managing Andina's metallurgical program and completed a series of bottle tests on the material.

The individual column tests comprised 60-kilogram charges of material stacked in 10-foot tall, 6-inch diameter columns. The test material was agglomerated with cement (3 to 8 kg/t), which maintained pH levels between 9 and 11. Solution application rates were standardized at 5.10 litres per day with a concentration of 1.0 gram per litre NaCN. Cyanide consumption was low ranging from 1.24 to 2.51 kg/t. The comparatively higher cement and cyanide consumption observed in Test B were due to sulphide mineral oxidization of the ground sample while it was in storage for approximately a year.

Mineralization Hardness Testing

Three Dorado West Zone composites (samples C, D and E) were submitted to SGS Minerals Services, Lakefield, Ontario, in order to determine their Bond Work Indexes (relative hardness). The samples had Bond Work Indexes ranging between 11.6 to 13.4 kWh/t (see table 1), which can be characterized to fall within the moderately soft to medium range of hardness. As a result, the anticipated wear life of HPGR rolls is expected to be minimally in the 9,000 to 9,500 hour range, corresponding to a low wear rate.

Continued Metallurgical Testing

The initial metallurgical tests were completed on mineralization form the Dorado West Zone deposit which hosts the majority of the gold resources outlined to date (Andina press release dated October 22, 2007). Tests are presently being completed on a composite sample from the Dorado East Zone deposit and from a composite of low-grade (0.35 g/t Au) gold mineralization. Additional samples are being prepared for further testing.


Under the guidelines of National Instrument 43-101 ("NI 43-101") of the Canadian Securities Administrators, the qualified person for the Volcan Gold Project is Ralph Gonzalez, a resident of Burnaby, British Columbia, Canada. Mr. Gonzalez is a professional engineer registered with the Association of Professional Engineers of the Province of Manitoba since 1977 and a Professional Geologist registered with the Association of Professional Engineers and Geoscientists in the Province of British Columbia since 1992. The October 2007 resource estimate was prepared by NCL Ingenieria y Construccion S.A., Santiago, Chile in conjunction with Eduardo Magri, Ph.D. in mining engineering (Witwatersrand) and a Fellow of the SAIMM with over 30 years of industry experience. Mr. Gonzalez is an independent qualified person as defined by NI 43-101. A NI43-101 compliant technical report related to the October 2007 resource estimate is being prepared by Mr. Gonzalez and will be filed on the SEDAR system ( prior to December 6, 2007.


This release contains forward-looking statements, including predictions, projections and forecasts. Forward-looking statements include, but are not limited to, statements with respect to exploration results, the timing and success of exploration activities generally, permitting time lines, government regulation of exploration and mining operations, environmental risks, title disputes or claims, limitations on insurance coverage, timing and possible outcome of any pending litigation and timing of future resource estimates. Often, but not always, forward-looking statements can be identified by the use of words such as "plans", "planning", "expects" or "does not expect", "continues", "scheduled", "estimates", "forecasts", "intends", "potential", "anticipates", "does not anticipate", or "belief", or describes a "goal", or variation of such words and phrases or state that certain actions, events or results "may be", "could", "would", "might" or "will" be taken, occur or be achieved.

Forward-looking statements involve known and unknown risks, future events, conditions, uncertainties and other factors which may cause the actual results, performance or achievements to be materially different from any future results, prediction, projection, forecast, performance or achievements expressed or implied by the forward looking statements. Such factors include, among others, the interpretation and actual results of current exploration activities; changes in project parameters as plans continue to be refined; future prices of gold; possible variations in grade or recovery rates; failure of equipment or processes to operate as anticipated; labour disputes and other risks of the mining industry; delays in obtaining governmental approvals or financing or in the completion of exploration, as well as those factors disclosed in the company's publicly filed documents. Although Andina has attempted to identify important factors that could cause actual actions, events or results to differ materially from those described in forward-looking statements, there may be other factors that cause actions, events or results not to be as anticipated, estimated or intended. There can be no assurance that forward-looking statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements.

The TSX Venture Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release.

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