SMC Test

The SMC Test® - a cost-effective means to predict comminution circuit throughput, rock mass characteristics and blasting properties.

The SMC Test® was developed by Dr Steve Morrell of SMC Testing as a cost-effective means of profiling an ore body to predict its comminution circuit throughput as well as its rock mass characteristics and blasting properties. Energy requirements for crushing and HPGR options can now be determined in addition to AG/SAG mills, and with Mic, ball mills. The results from conducting the SMC Test are used to determine the so-called drop-weight index (DWi) which is a measure of the strength of the rock.

The Drop Weight Index (DWi) is a measure of the resistance of a sample to impact breakage. The DWi:

  • Is measured in kWh/m3 and is directly related to the JK breakage parameters, A and b, which are used in JKSimMet for design and optimisation of AG/SAG Mill circuits.
  • Correlates with the Point Load index and UCS.
  • Is relatively easy to carry out and should always be used in place of the Bond BMWI test for SAG Milling. The Bond BMWI has no correlation with the throughput or power requirements of a SAG Mill.
  • Should be carried out on samples from each ore domain and in conjunction with a full JK Drop Weight Test for correlation purposes.

The SMC Test requires approximately 30 to 40kg or ore, significantly less sample than the JK Drop Weight Test or JK Rotary Breakage Test. Two sample preparation methods are available- the cut core method where the ore sample is competent and restricted in quantity, and the crush and select method where the ore is available in larger quantity or is friable.

Sample Requirements: The length of core required for the two methods are shown in the table below.


For larger diameter core, greater lengths are required for the cut core method. Half core, quarter core and crushed rock can also be used. Lengths in the above Table must be multiplied by a factor of two for half core and four for quarter core, respectively.