The JK Drop Weight Test was developed in the laboratory at the JK Centre in 1992 as
a means of measuring the impact breakage parameters of an ore. 

The JK Drop Weight Test provides ore specific parameters which are used in the JKSimMet Mineral Processing Simulator software to analyse and/or predict AG/SAG mill performance.  The same test procedure also provides ore type characterisation for the JKSimMet crusher model.

In an AG/SAG mill, there are two main mechanisms of breakage: impact (high energy) and abrasion (low energy).  The JK Drop Weight Test measures the impact and abrasion parameters for a specific sample of ore:

• The abrasion breakage parameter, t_a, is determined by a tumbling test.

• The impact breakage parameters, A and b, are determined using a high energy impact breakage device called the JK Drop Weight Tester.

Click here to find out more information about the JK Drop Weight Test. 

The JK Drop Weight Test is now an industry standard for use in characterising ore under AG/SAG milling conditions and is available at the JK Centre, various commercial laboratories, and at in-house company laboratories around the world.  JKTech recognises the responsibility of ensuring test standards are maintained and as a result:

• JKTech conducts frequent in-house checks of the JK Drop Weight Test procedure and equipment, and

• JKTech organises regular comparative calibration tests with all of its commercial and private JK Drop Weight Test licensees. These tests confirm the validity of the standard procedure as well as giving a measure of the relative accuracy of the results.

Sample Requirements

1. The minimum quantity of sample required to provide sufficient particles for testing is 100 kg of crushed rock in the -75+12.5 mm size range, or 120 kg of drill core.  JKTech can prepare a sample to the specified size range from a larger amount if required.  For diamond drill core samples, the core must be un-split and have a diameter of at least 50 mm.  Slightly more material is preferred if Bond rod mill and/or ball mill work index testing is also required. 

2.  Download the Sample Transmission Forms, which include Sample Hazard Advice Form and Quarantine Declaration Forms.  A completed Sample Hazard Advice Form must accompany or arrive in advance of every sample shipped to JKTech.  In addition, a Quarantine Declaration must be completed for every sample originating from outside Australia.  

To arrange for a JK Drop Weight Test to be carried out at JKTech, contact the JKTech Laboratory Services Manager.

The JK Drop Weight Test is also available from a number of licensed commercial laboratories.