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Gold/Mining/Energy : PolyMet Mining Corp POM.V (was Fleck Resources) -- Ignore unavailable to you. Want to Upgrade?

To: Elizabeth Andrews who wrote (520)	9/11/1998 12:14:00 PM
From: Shaun M. Dykes	Read Replies (1) \| Respond to of 708

The First two lab scale tests were completed in the fall of 1997 by major metallurgical laboratory (RPC) and used naturally occuring bacteria. Both tests were successful in recovering +95% FROM THE CONCENTRATE. In nature bacteria exist which love to digest sulphide, whats left is metals. The process has been used successful to treat concentrate and raw rock in several producing mines. Search the net using words like bioxidation, bacterial leaching, Ashanti, Gencor. The mining journal has talked extensively about bioxidation (bacterial leaching) in gold and copper mines. Note: At Dunka the bacteria work on the concentrate not the original rock, concentrate is produced in the normal manner as other mines of this type throughout the world. Overall recoveries FROM THE ROCK of +85% copper and +65% Nickel were used in the economic analysis It has been proven to work on a small scale at Dunka Road and leading metallurgists have all said it will work on a large scale. This is one of the purposes of collecting a sample that can be used to confirm the bacteria will work on a larger scale. The use of bacteria is just one of the methods being investigated, results from hydrometallurgical methods (leaching, acid washing etc.) have also been shown to work on a small scale. The current problem is simple which of the various metal recovery processes will be the most economic and efficient to use. The material from the current large diameter drilling will be able to resolve this question. An additional bulk sample will have to be taken later when it becomes time to fine tune the actual flow sheet for the mill design, when it becomes time for a feasibility study. It is important to note that the majority of work on Dunka Road was completed prior to 1990 and metallurgical recovery techniques have improved several orders of magnitude since then. We are not talking some fancy new recovery system or assay technique, the processes used all exist and are used by producing mines in different parts of the world.