Abstract: Following an introduction to the structure,working principle and technical features of the shallow-trough heavy medium separator,the paper goes to dwell on the restrictions imposed by the operation of the separator.To resolve these problems,work is made on the renovation of several parts of the separator including the tapered bearing,hydraulic cylinder,pinning tool,chute of reject screen,etc.The renovation has led to increased coal separation efficiency,improved quality of products,and,hence,more favourable economic and social result.