Tenders for Preventive Maintenance Works In Conveyors 14, 16, Erh Tunnel And Bfd 11A, 11B, 12A&12B - Clearing The Spillage Coal Powder Round The Clock In The Walkway, Decking Sheet Area And Cleaning Of All The Equipments In Conveyors14, 16 And Belt Feeder11a, 11B, 12A&12B For A Period Of 120 Days From The Date Of Commencement Of Work