Abstract: For effecting high-density separation of pyrite sulfur from coal refuse using magnetite powder, the paper starts with an introduction to the category of and the technical requirements placed on the commonly used magnetite powder. It is noted that the separation of pyrite sulfur from coal refuse requires a stable higher separation density, which is generally controlled in a range of 2.2～2.75 g/cm³. However, it is very hard to maintain and control the above-mentioned density range with the use of magnetite powder. For addressing this issue, a study is made on 4 aspects—magnetite powder, concentrate of magnetic separator, parameters of heavy medium cyclone and density of medium in qualified medium tank. Practice shows that the use of magnetite powder for high-density separation of pyrite sulfur from coal refuse can not only guarantee the quality of the coal and pyrite sulfur separated from coal refuse, but also enhance the comprehensive utilization rate of coal refuse.