Testwork: Drop weight test

Testwork: Drop Weight Tests

The JK drop weight testing machine is used to generate data sets for two different comminution models:

• a fitted "A" and "b" for the "E_CS versus T₁₀" test result, which is used in JK SimMet to generate particle size distributions (ergo, the appearance functions).
• a fitted "drop weight index" (DWI) test result, which is used in the Morrell power model to predict the specific energy consumption of particle breakage for "standard particle size distributions" of a process feed and product streams.

The test is a 'per-specimen' test where individual specimens of prepared rock are hand-picked by the test operator and placed into the apparatus. The size and quantity of the specimens is different in the JK SimMet and Morrell SMC (DWI) procedures. Generally, the DWI procedure requires fewer specimens of smaller sizes, but is much quicker (and less expensive) to operate.

Sample Requirements

The drop weight test for use in JK SimMet, referred to here as the "full drop weight test", requires approximately 100 kg of material with a top size of 75-100 mm. When using drill core, this requires whole-diameter PQ core.

The drop weight test for use in the Morrell SMC model requires minimum 8 kg with sized between 25-40 mm (though smaller dimensions can be substituted if the coarser material is not available).

Trademarks

• JK SimMet and JK DWT are trade marks of the Julius Kruttschnitt Mineral Research Centre, Indooroopilly, Australia. Laboratories performing this test pay a royalty when submitting raw results for interpretation.
• SMC and DWI are trade marks of SMC Testing Pty Ltd, Chapel Hill, Australia. Laboratories performing this test pay a royalty when submitting raw results for interpretation.