Crusher for critical size material at Los Bronces semiautogenous grinding plant, Chile

Abrasive grinding, leading to ultrafine product and "critical size" material buildup inside the mill, is proposed as the cause of high power consumption and low capacity in many fully autogenous grinding processes. Addition of steel balls (hence, semiautogenous grinding) or pebble removal and separate crushing have been used, with different efficiencies, to overcome the problem. Information and data for the conceptual analysis, basic design, and operation of a pebble crusher at the Los Bronces semiautogenous grinding plant is presented along with data showing a production increase of 1000 t/d (1100 stpd) and significant operating costs savings.