Based on the 5 SAGDesign test work results, the EEL Almonaster la Real ore demonstrates moderate ore competency for SAG milling and moderate to hard ore competency for ball mill grindability. The number of SAGDesign tests performed for this project is relatively low and it is recommended that additional SAG variability test work be performed to ensure that the ore hardness variability of the Almonaster la Real deposit is well characterized. The mill sizing and throughput calculations are evaluated with grinding circuit feed size F80 of 152,4 mm and two final grind sizes P80 of 75 and 44 µm. The mill sizing and throughput calculations in this report were evaluated based on the hardest sample tested since the difference in total pinion energy in kWh/t between the hardest and average of the samples tested was less than 4%. Equipment design based on average ore hardness values yields smaller mills that may be subject to greater fluctuations in throughput in the event of processing harder than average ores. The design point corresponding to the hardest sample had a SAG pinion energy of 9,73 kWh/t and a SAG discharge BWI of 11,05 kWh/t. To process the 6.000 average t/d throughput target and grind from F80 152,4 mm to a final product P80 75 µm, the recommended equipment configuration is a conventional single line grinding circuit with 1 SAG mill followed by 1 ball mill in series (2,8 MW total installed power). The recommended SAG mill size is a 18.0 ft (5,5 m) diameter x 9,03 ft (2,8 m) EGL mill equipped with a 1,400 kW single pinion fixed speed synchronous motor drive. The mill chamber is sized for average ore specific gravity with 26% total charge volume, 10% steel load and a mill rotation speed of 75% critical. The SAG motor is sized with 10% operating allowance on the installed motor. The mill shell strength is to be designed for 20% steel and 35% total load to allow for inadvertent mill overloading. The SAG mill is designed to process feed with a feed size of F80 152,4 mm and produce a T80 transfer size of 1.000 µm. The SAG mill power draw at design tonnage is 1.283 kW (91,6% of installed power).
|Translated title of the contribution||Comparison between one staged and three stages crushing plant in a Copper Mine Operation|
|Publication status||Published - 2016|