Haiyan Tonghui Mining Crusher Machinery Co Ltd
A. Gupta, D.S. Yan, in Mineral Processing Design and Operation, 2006 6.1.3 Roll Crusher Circuit Design. Roll crushers are generally not used as primary crushers for hard ores. Even for softer ores, like chalcocite and chalcopyrite they have been used as secondary crushers. Choke feeding is not advisable as it tends to produce particles of irregular size.Jul 17, 2020 IN one the biggest protest actions during the lockdown, five and a half lakh coal workers of Coal India Limited (CIL), a public sector undertaking, and Singareni Collieries Company Limited (SCCL), which is jointly owned by the Union government and the government of Telangana, will go on strike for three days from July 2 to protest against the decision of the National Democratic Alliance.