June 15th, 2001

ASTURIUS, Spain - Two recently installed Knelson CD12 Concentrators, fitted with the optional Knelson Variable Gravity Packages, are achieving unprecedented fine gold recovery at the Rio Narcea Gold Mine in Spain.

"It's quite remarkable when you consider that the Knelson units are achieving in excess of 70% recovery in a single pass of which over 83% of the values are in the -38 micron fraction," commented Ish Grewal, Manager of Knelson's Research & Testing Centre.

Description %Wt G/t Au Au Dist. > 53um 5.5 70 1.5 > 38um 12.8 130 6.7 > 10um 50.3 388 78.0 < 10um 31.4 110 13.8 Total 100.0 250 100.0 Table 1: Gold Deportment in Copper Concentrate

Description %Wt % Au Au Dist. > 53um 27.6 0.16 5.5 > 38um 17.8 0.51 11.4 > 10um 37.6 1.67 78.8 < 10um 17 0.2 4.3 Total 100.0 0.8 100.0 Table 2: Knelson Concentrate Size by Size Recoveries

Initial testwork on the copper concentrates was conducted at G-forces as high as 200, although performance was optimized at around 150 G's on this finely disseminated feed stream.

"The driving force behind this installation was the fact that the smelter payment on gold in the copper concentrate was being discounted. There was significant opportunity to improve on this by removing as much gold as possible to a gravity concentrate, and subsequently to higher paying gold dorй which is produced on-site" observed Doug Corsan, VP of Sales for Knelson.

The work at Rio Narcea parallels some very similar work at BHP's OK Tedi Mine in New Guinea which has also resulted in the installation of two Knelson CD12 units on concentrate duty.

"Recovery of precious metals from various types of base metal concentrate streams is an area of growing interest throughout the industry as producers look for innovative ways to improve efficiency, reduce costs and increase revenues," added Corsan.

Knelson would like to thank the entire metallurgical staff and management at the Rio Narcea Gold Mine along with the staff of European representative South West Metallurgical Services for their ongoing support and commitment to this project.

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