Analysis of the causes leading to the high consumption of medium at Ningdong Mine Coal Preparation Plant and countermeasures

In order to reduce the medium consumption of each coal preparation plant in Ningdong Mining Area, an analysis is made of the causes leading to the high consumption of medium using technical random inspection and statistical analysis methods. Result of analysis shows that the direct cause is the loss of medium which is carried away by tailings of magnetic separator due to high concentration and high content of nonmagnetics of feed, and overloading of the magnetic separator; the preliminary desliming process is not the direct cause leading to the high concentration of the separator′s feed; and the basic reason is that the magnetic separator works with a poor performance due to the facts that the qualified medium sections of both fixed screen and medium draining screen are all low in operating efficiency. Through improvement of the medium draining effects on both screens, fitting an innovative diversion turnover plate under the medium draining screen, renovation of the magnetic separator′s feed collecting box with flow splitting functions and taking in particular effective measures to realize thorough draining of qualified medium from screen, a tangible result has been obtained with the medium consumption at each plant in the mining area being reduced by 0.19 kg/t.