The plant has been achieving excellent grades as well – both chemical and metallurgical chrome

ChromTech has added a new process plant designed to retreat old PGM material to extract chrome from a historical mine dump within Lonmin’s Marikana property.

Laura Cornish visited the site with ChromTech’s CCO, Jono Gay, to learn more about this latest achievement and its ‘smart-thinking’ strategic approach to delivering a sound business that is well positioned for growth.

This article first appeared in Mining Review Africa Issue 11 2018.

Situated in the heartland of PGM mining territory in South Africa, 26% black owned and ISO-compliant ChromTech’s new tailings retreatment plant lies in close proximity to the Marikana mine and 10 km from the tailings dam for which it has secured the rights to retreat chrome material.

With a long and successful track record operating in this specific field, Lonmin elected ChromTech to take on the project and awarded it to the company in 2015.

From left to right, Graeme Smith, Jono Gay and Mechiel Ras (ChromTech lead process engineer) on site at the plant

After securing the necessary regulatory requirements and cash which saw the IDC provide debt capital upfront (a first for Gay), the company commenced with construction of the retreatment plant in 2017 and commissioned it early in 2018.

“It took only three months to take the plant up to nameplate capacity,” Gay notes.

And despite fluctuations in the feed size, the plant has been delivering according to its requirements and achieving excellent chrome grades as well – in both chemical and metallurgical chrome.

“This is the sixth plant we have delivered in our 12-year history and at 300 000 tpm (with a 20% over-run capacity) is the second largest (by capacity) that we have built and operated in our history.”

At this rate, ChromTech will comfortably reprocess material for about eight to 10 years and produce in the range of 30 – 40 000 tpm of chrome which it will sell directly to end users in the global chemical and alloy market.

The material is delivered to site via a newly constructed 10 km overland pipeline that feeds the ore directly into the plant.

Once the chrome has been extracted it is delivered to Lonmin’s adjacent concentrator plant for additional PGM extraction.

The plant itself is incredibly neat and compact, occupying a very small footprint. This explains why the heart of the operation, the spiral plant, stretches multiple stories high.

“The success of this operation can be attributed to our business philosophy of designing our own plants using our own in-house process engineering team who also partner with hand selected technology service providers to maximise our results and objectives,” Gay highlights.

“With a quick and flexible management structure who can make decisions without hierarchical red tape processes, and a full 12 years of operational learnings incorporated into this plant, we have a process that is truly delivering results for us.”

Large fluctuations in feed size as mentioned, for example, is something ChromTech had to account for during the design, which consequently led to the construction of plant which offers a lot of operating flexibility.

“We believe we have created a very bespoke tailings retreatment operation that produces high quality chrome materials.”

Multotec also supplied the cyclones for the ChromTech tailings recovery plant

Because ChromTech also believes in collaborating with technology partners who share similar ideals and principles, it chose to unite with process equipment specialist Multotec for the supply of all of the plant’s spirals which Gay says are cost competitive and the most efficient in the industry.

Having previously worked with an alternative spiral supplier, the company has now elected to move forward working closely with Multotec on all spiral requirements.

To insure the delivery of an optimal result from the start, Multotec application engineer Graeme Smith played an integral role in the spiral layout review of the spiral plant.

This provided extensive test work upfront and played an active role throughout the construction and commissioning timeframe.

“There are 600 spiral starts in the plant and more than 240 spirals in total. The large diameter spirals are recovering material down to 24 microns in size. This is excellent in terms of our recoveries but we are still looking at options to recover the ultra-fine material.”

“We believe our success is also as a result of our expertise and close collaboration with Multotec throughout the duration of project. They are our first choice technology supplier in spirals and also cyclones.

“And because of its small footprint and flexible structure, our plant has proven itself easy to operate and maintain using 75 full time employees – the majority of those from the local community.”

Who is ChromTech?

In the 12 years since the company was established in 2006, ChromTech has established itself as an expert in providing a fully integrated service offering to the chrome tailings recovery market.

Its projects extend back to and include tailings recovery operations for the Crocodile River PGM mine, a 420 000 tpm plant at Anglo American Platinum’s Waterval mine as well as a 120 000 tpa plant at Lonmin’s K3 operation.

Today the company is operating three plants: at Marikana, Waterval and Cronimet. Across its operations it employs some 300 people.

What further contributes so heavily towards the success of ChromTech is its in-house ancillary support structure which underpins its core business and gives it greater control over the upfront and final processes once the product has been produced.

This ranges from in-house engineering and design (as we know) to full construction management, sales and marketing logistics management as well as strong finance and administration support.

ChromTech is for example building its own railway siding between Rustenburg and its new tailings recovery operation – giving the company total control over its entire end-to-end service offering.

And with such a strong team and a solid track record, ChromTech is eager to continue looking for the right opportunities to build its business further.

This now includes a close look at the base metals arena as well as further afield into the mineral-rich Zimbabwe.

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