Figure 38 shows a set of Run-of-Mine particle size distributions along with their corresponding Axb values from selected open-pit mines in the JKTech database. It is observed that there is a good correlation between blast fragmentation and ore competency as measured by the JK Drop Weight or SMC Test®, in line with fundamentals. It should be noted that all these blast fragmentations correspond to rock quality designation (RQD) values above 87.5 %. It has been found that poor RQD values <65-87.5%> can potentially bias blast fragmentations toward the fine end irrespective of the Axb value. Figure 38 – Run-of-Mine PSD with Corresponding Axb in the JKTech Database Figure 6 compares actual mill throughput with throughput predicted by a Specific Comminution Energy model developed using five variables that have shown statistical significance with mill throughput: total milling power draw, feed size, final grind size, Axb, and Bond BMWi. At this gold mine in the Southeast Asia–Pacific region, both Axb Anvil Drop weight Guide Rod Winch Perspex enclosure Concrete platform Rock specimen Figure 37 – The JK Drop Weight Tester
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