Arising from a tender issued by China Coal for the Pingshou East Open Pit mining area in Shanxi Province, China Coal Energy Group signed a contract in February with MMD for the supply of an IPCC system including an MMD Mobile Sizer. The order, which also includes some ancillary equipment, was received by MMD via its MMD China operation. With a contracted delivery period of 17 months, the system will be jointly supplied by MMD in the UK and their wholly owned subsidiary MMD China, based near Beijing. The core MMD components will be manufactured in the UK with the balance being manufactured, sourced and assembled by their Chinese team who will, with the support of the specialist MMD IPCC team, also take charge of the site assembly and after sales support of the system. Commissioning is expected in mid 2012. This represents the first of the third generation MMD high capacity (>5000tph) fully mobile sizing units to go into operation.
The system will be used to handle overburden, consisting primarily of sand stones with a hardness of up to 120Mpa and density of 2.7kg/cm³. The horizons contain several muddy layers and are expected to get sticky in the short wet season, as the daily precipitation can exceed 150mm/d. The material deposits, from the 15m high benches of up to 1540m in length, will be loaded in to the MMD Mobile Sizer by a 60m³ capacity rope shovel.
The material is then transferred from the 150m³ hopper by a low angle MMD D9 Apron Plate Feeder, capable of providing a controlled flow rate of up to 10,000TPH to the MMD Twin Shaft Mineral Sizer. The Sizer reduces the ROM material (maximum dimensions 2.5m x 2.5m x 2m) to a product size suitable for belt conveying (400mm) before feeding it on to a short transfer conveyor which carries it to an integral luffing/slewing discharge conveyor.
An independent mobile 70m long bridge conveyor, also part of MMD scope, feeds the MMD mobile hopper car mounted over the relocatable face conveyor. The face conveyor and subsequent stacking and spreading systems are not part of MMD's scope of supply.
When in full production, the MMD Mobile Sizer will move hourly, with the normal advance being a distance of 5m. According to MMD, the Mobile Sizer's low profile, compact and balanced design, coupled with its ability to continue sizing whilst moving will make for a virtually seamless loading operation.