Oct 20, 2017

Lorena processing model leads the way

Lorena processing model leads the way

The Lorena gold operation is the debut project for a new mining and processing model desperately needed for industry growth in the North, according to BIM Metals managing director Brendan James.

Mining is set to begin at the site, 15km east of Cloncurry, next week and commissioning will start soon on the front end of the processing plant.

BIM Metals has been providing consultancy and management advice as Malachite Resources and OPS (Ore Processing Services) develop the project, expected to have an output of 30,000-35,000oz of gold over an 18-month mine life.

BIM Metals is primarily working with OPS, providing metallurgical expertise as that company develops a business in constructing relocatable processing plants suited for multiple lives in the north Queensland mining industry.

Mr James said they would have a throughput capacity of about 300,000tpa to 1Mtpa and the ability to be shifted from one mine site and restarted at another within a month.

“This is something I think the industry, particularly out in the Cloncurry region, has needed for some time – the ability to bring in modular plants that can support projects that generally don’t have a life long enough to support building an all-new processing plant,” Mr James said.

“You can bring in a plant and, at the end of the project, take the plant away and use it somewhere else.”

Change of direction

The back story for Lorena is complicated.

Malachite Resources was originally working with BCD Resources to develop the gold project.

The intention was that ore would go through a flotation process on site and the concentrate would be shipped to BCD’s Beaconsfield facility in Tasmania to produce gold doré.

That plan collapsed when BCD went into administration in 2015.

Malachite then teamed up with OPS with a new plan to construct a modular processing plant that better suited Lorena’s high gold grade but small tonnage.

OPS has taken over responsibility for the front end of the processing stream at Lorena as well as constructing a modular CIL (carbon-in-leach) circuit to allow the production of gold doré on site.

“By utilising OPS, Malachite has access to a plant which can be taken away at the end of the project, with the flexibility that if Malachite finds more gold and wants to go underground then obviously the plant can stay on site until the operations are completed,” Mr James said.

New players join project

Malachite announced to the market in July that its Lorena Gold Project Joint Venture had been extended to bring in Chinova and BIM Gold via their Cloncurry Gold Recovery Joint Venture.  This included a $2.5 million capital injection to kick off the Lorena Gold Project.

BIM Gold – a separate business entity to BIM Metals – will undertake the mining at Lorena and is busy on site building the tailings dam.

Chinova has also become involved in the Lorena venture, as the majority owner of the CIL plant.  Chinova sees added value in relocating the CIL Plant in the future onto its own site for tailings retreatment when production at Lorena winds up.

BIM Metals previously worked with Chinova through an open-pit mining contract  which wrapped up earlier this year at the Osborne copper-gold mine, 195km south-east of Mount Isa.

Preparation work at the Lorena gold mine.

“One thing we saw was that they needed a CIL plant to treat old gold tailings on site,” Mr James said.

“OPS wanted to build a gold plant but it needed a second life after Lorena – so we were able to facilitate those two companies coming together.”

The model being used to get Lorena off the ground could work repeatedly across north-west Queensland and elsewhere, Mr James said.

“The idea for OPS is to build up the number of mobile and modular plants it has and it can then distribute across other projects,” he said.

“It really opens things up for high-value projects that don’t necessarily have that long life to support a standard processing plant build.

“I think it’s a great model. We’re providing a lot of metallurgical consultancy support to OPS.”

‘Desperately’ needed

He believed the resources industry desperately needed the project model OPS and BIM Metals could facilitate.

“We’re getting to the point  – barring any new finds – where the undeveloped resources out there are either massive and low grade, so need very big plants and very big capital (expenditure), or they are small and high grade,” Mr James said.

“The stuff in between – the 15-year projects, middle of the range – are largely done.

“We can’t specialise in the massive low-grade projects like the large mining companies. What we are focusing on is a solution to be able to develop and open up these small short-life but high-grade and good quality projects like Lorena. The industry desperately needs it.”

Recent Stories

Subscribe to IQ Now