北部采选公司的生产运输系统,由一个铁路运输部和两个汽车运输车间组成。铁路运输部门保证采矿生产、选矿厂和球团厂不间断地进行工作。铁路运输部门的固定资产占采选公司全部固定资产的10～12％。铁路线总长304公里,其中固定线231 The production and transportation system of the northern mining company consists of a railway transport department and two automotive transport workshops. The railway transport department guarantees that mining production, concentrators and pelletizing plants will continue to work. The fixed assets of the railway transport sector account for 10% to 12% of the total fixed assets of the mining companies. The length of the railway line is 304 kilometers, of which fixed line 231