Pit & Quarry, October 2010

W A S H I N G A Quebec City aggregates producer installs a new plant to increase capacity while producing better material E ntreprises PEB Division Agrégats Québec Métro is an aggregates producer in Quebec City The Canadian company was looking for ways to increase production manage its pond area and wash its natural sand deposit which is very high in fines Entreprises PEB found the solution in an Ultra Sand Plant dewatering screen wash plant Ultra Fines Recovery UFR system and thickener tank from McLanahan Corp The operation begins with dry recovery using Caterpillar loaders and haul trucks To create a manufactured sand product material is crushed on site using a series of crushers a Metso 30x54 primary jaw Svedala secondary cone and Metso HP400 tertiary cone There are two material feeds to the plant natural sand 15 to 30 percent passing 200 mesh and manufactured sand 10 to 15 percent passing 200 mesh Enterprises PEB processes one or the other depending on what is required explains Claire Hayek process engineer and Canadian regional manager for McLanahan Corp Washed natural sand spec is 6 to 8 percent passing 200 mesh she says and washed manufactured sand is 3 to 4 percent passing 200 mesh New plant The sites new McLanahan Ultra Sand Plant includes two VD18 dewatering screens 6 ft x 12 ft a 36 in separator two sumps and a 10x8 pump The McLanahan UFR system includes three 12 in cyclones VD15 dewatering screen 5 ft x 12 ft a sump and an 8x6 pump The systems water management uses a 30 ft diameter McLanahan thickener tank with a 4x4 pump and 20 ft diameter clean water tank The sites UFR system manages washplant reject and minimizes pond volume The thickener tank is fed by the UFR system reject mainly minus 30 micron fines and water The thickener tank is used to decant fines from water and recycle clean water back to the wash BY DARREN CONSTANTINO Photos by Claire Hayek Take note It is estimated that if the Ultra Fines Recovery system and thickener tank werent installed the pond size would have to be eight times larger to accommodate the increased capacity 10 PIT QUARRY October 2010 www pitandquarry com