Abstract: In order to solve the problems of high beneficiation cost and poor comprehensive index caused by water shortage in an iron mine in Western Inner Mongolia，a new technology of dry grinding and dry separation with roller mill and multi-stage particle separator as the core equipment was proposed on the basis of process mineralogy research. The industrial test results of the iron ore expansion project show that the new technology of dry grinding and dry separation can separate three kinds of narrow grade particle size ore particles in the grinding process，and discard the tailings by dry magnetic separation respectively. The total discarding rate is 11.5%，the magnetic iron grade of tailings is less than 1%，and the tailings are qual⁃ ified building materials. The results of dry magnetic separation conditions of iron ore powder show that when the fineness of iron ore powder is -0.074 mm account for 71.31%，the dry separation effect is better; the tailings discarding rate is 32.6%~44.56% by using different magnetic separators for dry separation. The magnetic iron grade of tailings is not much different from that of wet separation，and the total tailings dis⁃ carding rate is 40.35%~50.94%. The dry tailings of iron ore powder are stone powder，which can be used as building materials，cement raw materials，filling materials，etc.，or dry stacking. The new technology of dry grinding and dry separation of iron ore greatly improves the tailings discarding rate of iron ore，reduces the cost of beneficiation，and has wide applicability.

Key words: Iron ore, vertical roller mill, dry grinding and dry separation, tailings extraction, grade