Societe Des Mines Du Bourneix

Summary Report from F. Meia; Mine Manager
September 8th, 1993 Perche, France

September 14th, 1999

This single page report summarizes the installation of a fully automated 20" Knelson CD Concentrator in this 70,000oz./year gold mine in Southern France. The mill flowsheet is crushing/ grinding/ flotation/ cyanidation of flotation concentrate via C.I.P./ carbon roasting. Prior to the addition of the Knelson Concentrator, the grade of flotation tails would range from 0.3 to 1 g/t which prompted management to conduct a study aimed at reducing tailings losses.

After several months of pilot testing with a 7.5" Knelson Concentrator, the decision was made to install an automated 20" Knelson CD Concentrator to scavenge gold from the flotation tails. The gold values recovered are predominantly greater than 100mm indicating the inability of the flotation circuit to effectively recover free gold particles in this size range.

"It was decided to acquire a 20" Knelson Concentrator in order to recover free gold from the tailings. The tailings coming from flotation are cycloned. The underflow greater than 100mm is fed to the concentrator. The concentrate grades more than 1800g/t. The amount of gold recovered from this is in line with the results of the pilot test i.e. 3000 grams per month, increasing the total gold recovery by 1.5%."

"The CAPEX (capital expenditure) payback is less than 4 months. This confirms the efficiency of the Knelson Concentrator to recover free gold and increase the profitability of the mine." Download the whole report:

Societe Des Mines Du Bourneix 19k | 1 page Acrobat Info Sheet