This month, the Australia-invented SMC Test®, used by leading mining companies over the globe to improve concentrator performance, optimise throughput, and decrease energy use, reached its 50,000th test. This makes it, the company says, the most widely used comminution test in the world for AG & SAG mills, HPGRs and crushers.

The SMC Test database spans over 1,900 orebodies, 100 countries and 47 different commodities ranging from copper, gold, and iron to diamonds and rare earths. This makes it the largest database of its kind in the world, according to SMC Testing, giving unparalleled insight into the energy required to fully extract valuable minerals from ore.

A laboratory comminution test that provides a range of information on the breakage characteristics of rock samples for use in the mining/minerals processing industry, the SMC Test uses either crushed rock pieces that are very closely sized (‘crush and select’ method), or particles cut to similar size from drill core using a diamond saw (‘cut core’ method). The latter approach is used when a limited drill core sample is available, with almost any drill core size suitable, even core that has been quartered (slivered).

The chosen rock particles are broken using a closely controlled range of impact energies on a JK Tech Drop Weight Tester. The high degree of control imposed on both the size of particles and the energies used to break them means the test is largely free of the repeatability problems that plague tumbling mill rock characterisation tests, SMC Testing says. The results from the SMC Test are used to determine the drop-weight index – a measure of the strength of the rock as well as the comminution indices Mia, Mih, and Mic. In conjunction with the Bond ball mill work index, they can be used to accurately predict the overall specific energy requirements of circuits containing AG and SAG mills, ball mills, rod mills, crushers, and high pressure grinding rolls (HPGRs).

The SMC Test also generates the JK rock breakage parameters A, b, and ta as well as the JK crusher model’s t10-Ecs matrix, all of which are generated as part of the standard report output from the test. These values can be used to simulate crushing and grinding circuits using JKTech’s simulator – JKSimMet, according to SMC Testing.

The SMC Test’s broad-ranging uses include comminution plant design, circuit performance optimisation, throughput forecasting, geo-metallurgical modelling, as well as cutting energy costs and reducing CO2 emissions.

“The precision and accuracy of the SMC Test have been the main driving forces behind its success globally,” Dr Steve Morrell, SMC Testing CEO and inventor of the SMC Test, said. “These attributes of the test are hallmarks of reliability and quality that mining companies base important forecasting decisions and financial models upon.

“It has been proven through benchmarking against an unprecedented 120 processing plants around the world, covering just about every type of comminution circuit in operation, including the largest to the smallest equipment available on the market, and treating some of the softest to the hardest ores that have been discovered to date.”

Used by 18 out of 20 of the largest mining companies in the world, the SMC Test helped Barrick Gold achieve a 20% net energy improvement and a reduction in CO2 emissions by 43,000 t, a cost saving of $5 million/y in energy costs, SMC Testing says. The comminution circuit throughput also increased annual gold production by 60,000 oz.

The approach taken to benchmark and improve Barrick’s global operations was later developed into an international guideline by the Global Mining Guidelines Group, called ‘The Morrell Method’. Morrell, meanwhile, in 2018, was inducted into International Mining Technology’s Hall of Fame.

Further increased efficiencies and cost savings include Batu Hijau in Indonesia, where a throughput decline was reversed and annual revenue increased by an estimated $150 million, while optimisation initiatives at one of Polyus Gold’s sites led to an annual increase in revenue of over $30 million with the assistance of the SMC Test. Compañía Minera Doña Inés de Collahuasi, the Chile copper asset co-owned by Anglo American and Glencore, meanwhile, has developed a 99.85% accurate throughput forecast model using the SMC Test.

“Many people assume that such large revenue benefits must mean that the SMC Test is expensive to conduct,” Morrell stated. “However, for what often works out as less than 1 cent per tonne of ore, there is a significant upside when resultant savings or revenue increases can be measured in tens-of- millions-of-dollars.”

SMC Tests can be done on as little as 5 kg of sample and ordered through a global network of approved laboratories licensed to conduct the test.