The family run quarry Bertrand Ch. in Bra sur Lienne/Belgium proves that a Keestrack Combo screen can improve the efficiency and profitability of even the smallest quarry. The quarry (Fig.) is known for its specific blue and brown slate. This is used amongst others in construction of walls, roofs, terraces, floors and dry walls (without mortar).
Mining the quarry is already 50 years in progress and this was mainly done manually. The stones have been sorted manually as ordered, and there was lots of waste. Nowadays the manual selection has been brought back to a minimum. Only a manual selection is done on colour and on specific shape of the stones. Another advantage is that the fines and middle fractions are very specific now, resulting in higher proceeds up to 15 times more. Also production has doubled leading to a shorter delivery time. Besides these economic solutions the Combo also provides a less labour intensive and much cleaner work environment. Quarry Bertrand has expanded their product portfolio because of the 3 different fractions in the new working process. The 0-50 mm fraction is used for paving forest tracks and roads and gardening decorations. The 50-120 mm fraction for drainage stone or as decorative stone.
The choice for the Combo, the smallest screen of the Keestrack range, was an easy one after a testing period of 2 days. Because manual sorting is still to be done at the oversize conveyor it is essential to have picking stations on both sides. Also the speed of the hopper and the main conveyor is easy to adjust from the picking stations. The easily interchangeable screens of the Combo are also an advantage. A capacity of 250 t/h is more than enough in this application.