Tag Archives: Batu Hijau

Macmahon defies labour tightness to bolster contract mining order book

Macmahon Holdings Ltd has added around A$1.35 billion ($988 million) of work to its order book with the signing of three previously flagged contract mining gigs, plus announced the addition of surface mining work at Northern Star Resources’ Julius gold project in Western Australia.

The three projects making up the A$1.35 billion of contract mining works are the 5-year agreement with St Barbara Ltd at the Gwalia gold mine, a three-year pact with Anglo American at Dawson South and a five-year contract with Red 5 Ltd at King of the Hills.

The contract with Northern Star Resources at Julius is expected to deliver revenue of A$25 million over the next 12 months. Production from the Julius deposit is expected to complement output from NSR’s Jundee operations.

In addition to these projects, Macmahon says it is well progressed in finalising the commercial arrangements for Phase 8 of its Batu Hijau copper-gold project in Indonesia, an operation owned by PT Amman Mineral Nusa Tenggara.

Macmahon commented: “While Macmahon has observed a tightening of the labour market in Australia over the past year, it can confirm that the Gwalia, Dawson South and Julius projects have commenced operations by the times required in those contracts.

“Macmahon has existing strategies for responding to challenges in the availability of labour, and believes it is well placed to continue to manage this operational issue into the foreseeable future, and to continue to deliver value for its clients.”

Commenting on today’s announcement, Macmahon CEO and Managing Director, Michael Finnegan, said: “Macmahon is continuing to build on its track record for delivery and to advance its growth strategy.

“It is very satisfying to have secured significant new work during financial year 2021, which provides us with a strong order book and excellent earnings visibility for FY22 and FY23. The underground work at Gwalia and King of the Hills also adds scale to our underground business, which is an important step in our strategy to diversify Macmahon.”

SMC Test comminution benchmark hits new milestone

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.

DAMM and Wellracom to digitalise Amman Mineral’s Baju Hijau copper-gold mine

DAMM and its systems partner, Wellracom, have successfully commenced an upgrade from an existing analogue system to a digital TETRA communication solution for Indonesia mining company, PT Amman Mineral Nusa Tenggara.

DAMM has delivered five 2-carrier DAMM Outdoor Base Station BS421s for voice and data communication for the entire mining operation, it said.

Key factors for choosing DAMM were the cost-efficiency and scalability of the system combined with the open API, DAMM said. DAMM says its MultiTech Platform enables voice and data communication across technologies, including TETRA, TEDS, DMR and Analog in one single system.

To facilitate the gradual migration to the new TETRA system, Amman Mineral has deployed a DAMM TetraFlex Group Bridge, which enables communication between the two different technologies. This will ensure a seamless migration and smooth integration, according to DAMM. The site will eventually become fully digitalised.

Amman Mineral operates the Batu Hijau copper-gold mine, in the West Sumbawa regency, West Nusa Tenggara province. This is the second largest copper and gold mine in Indonesia.

Desmond Cheong, Regional Manager at DAMM, said: “This has been an exciting project for us. It is great for us to demonstrate our ability to deliver communication in challenging conditions, a success that can be attributed to the high quality of our DAMM TetraFlex solution as well as our great collaboration with Wellracom.”

Mr Suprapto, Managing Director of Wellracom Group, said DAMM has a proven track record in the mining industry, adding: “The challenge in the mining industry, in Indonesia, is to secure communication 24/7 to minimise any disruption to operations.”