外文翻译波特兰水泥原料准备.docxVIP

外文资料翻译Portland Cement Preparation of Raw Materials1. Crushing The raw materials as received from the mines are in lump form and have to be crushed before fine grinding. The size of the lumps would depend upon theraw material and the method of mining, so the size of the crushing equipmentused would depend primarily upon the size of the lumps received. In a moderncement factory, manufacturing 1000 to 2000 tonnes of cement per day, the limestone is mined by mechanical means and hence the size of individual pieces maybe 1 meter or so. In smaller factories, the mining of limestone may be manualand the size of individual pieces may be 200 mm or so. Similarly, clay, shale,bauxite, laterite, sandstone, coal, gypsum, etc. may be received in sizes notlarger than 300 mm.(a) Limestone Crushers: The requirement of limestone per day for a 2000TPD factory may be about 2600 to 3000 TPD, for a 1000 TPD factory 1300 to1500 TPD and for a 300 TPD factory 400 to 450 TPD. As the mining operationhas to be carried out in daylight hours only, the crushing operation should alsobe carried out in the 10 or 12 hours of light per day. The capacityof a limestone crusher for a 2000 TPD factory may be 300 TPH, for a 1000 TPD factory 150 TPH and for a 300 TPD factory 50 TPH. The decision on the type of limestonecrusher would depend upon the physical properties of the limestone; however,for smaller factories using manually mined limestone, single stage HammerCrushers are most suitable; but for larger factories two stage crushing is alwaysmore economical and more efficient. The first stage may be a Jaw Crusher, Gyratory Crusher or Impact Crusher and the second stage a Hammer Crusher orCone Crusher. If possible, a screen of suitable size may be introduced after thesecondary crusher to allow only undersize to go for further processing whileoversize is returned to the crusher. A typical flowsheet for a limestone crushingplant in a 2000 TPD factory may be.Dumpers--Feed Hopper with Laminated conveyor at t