Differences in Properties between Pebbles and Raw Ore from a SAG Mill at a Zinc, Tin-Bearing Mine

Abstract

Semi-autogenous (SAG) mills are widely used grinding equipment, but some ore with critical particle sizes cannot be effectively processed by SAG mills and turned into pebbles. This research aims to analyze and compare the properties of raw ore and pebbles from a zinc- and tin-bearing ore. The results show that the contents of sphalerite, cassiterite, biotite, antigorite, pyroxferroite, ferroactinolite, and ilvaite in the raw ore are higher than those in the pebbles, and that the pebbles have higher contents of hedenbergite, chlorite, epidote, actinolite, etc. Meanwhile, the abrasion and impact resistance of pebbles is greater than that of the raw ore. In addition, the sphalerite is evenly embedded, and the grinding process is regular. Fine cassiterite associated with harder minerals is difficult to dissociate; it is often found in softer or brittle minerals which may be easily ground into ore mud. The cassiterite in the pebbles is associated with hard and brittle hedenbergite and soft chlorite, making it difficult to recover. This research provides a good foundation for evaluating the recovery value of pebbles and improving the productivity of the SAG process.

Keywords

• pebble
• SAG
• sphalerite
• cassiterite
• process mineralogy