Abstract: An HP 500 cone crusher was introduced into Fankou Leadzinc Ore mine in 2006 to reduce the crushing size from 11.5 mm to 9.5 mm. With the crushing size decrease, the ball mill capacity became a little surplus and it was planned to eliminate one primary grinding mill. Industrial tests were made on two different operation modes of ball mills. The grinding system capacities reached 5 500 t/d and 4 500 t/d respectively and the primary grinding mill capacities were improved by 25% and 33% respectively, with one primary grinding-classification system eliminated. Technical parameters of the grinding and classification can well satisfy the technical requirement of flotation process.

Key words: More crushing and less grinding, HP cone crusher, Primary grinding system