Rosh Pinah 2.0

Below-ground WiFi to strengthen production backbone
Augetto Graig
Augetto Graig - Terms like ‘data-lake’ and ‘cloud-hosted’ might seem out of place 600 metres underground, down endless pitch-black tunnels, at the bottom of a fifty-year-old zinc mine in the middle of the desert. Yet Rosh Pinah Mountain in the desolate Huns range in the lonely south now sits atop one of the most advanced and cutting-edge underground commercial lead and zinc mines in Africa.

Visible from the surface only as two big holes at the foot of the mountain, with towering heaps of rubble and the production plant between, and the town of Rosh Pinah spreading out front into the valley, and around the side of the mountain, the mine covers 4 km in length and 1.5 km across, down to a depth of more than 600 m below. Down there, fibre is being laid, autonomous drones scan stopes and take void measurements, and scoop trams are loading ore, operated by remote-control.

Trevali’s technology

Trevali has invested heavily in applied technology at its Rosh Pinah Zinc mine in Namibia’s deep south, to make these concepts commonplace and part of the everyday execution of duties for its 400 permanent employees and the 250 contract workers.

“In short, through Trevali’s investment in exploration and technology, we have discovered more ore to mine. With our improved technical understanding of the complexities and challenges of mining the new Western Ore Field, which makes up about 75% of our future minable ore, we were able to extend the life-of-mine from about 7,5 years in 2015, to 12 years in 2020,” elaborates Christo Horn , Vice President for Operations.

Examples of technology put to use at Rosh Pinah Zinc include the latest mine design and scheduling software, “geotechnical software to understand the behaviour of stress in the rocks when we mine. Real time rock stress and movement instruments like extensometers and geophones. Automation of underground fans, raised bore drilling, remote stope loading with scoop trams,” according to Horn. He says the wall bar survey system in use is the first of its kind in Namibia, and that Rosh Pinah Zinc was the first to make use of underground drones. The mine features underground fleet tracking, world-class underground refuge chambers and underground WiFi, he says.

Tier one deposit

Christo Horn, vice president for operations at Rosh Pinah Zinc says their tier one deposit had more than 50 million tonnes underground initially, and has been operational since 1969, with 21 million tonnes remaining in its fifty-second year in production.

“Trevali has, since 2016, increased the resource significantly, spending some N$54.8 million between 2019 and 2021, most of it on drilling. Back then we had seven and a half years Life-of-Mine. Now we have eleven years. With exploration and our inferred resources there could be another a 20-year potential,” he said.

According to Horn, Trevali brings a huge focus on technology, operating like a technology company to unlock the future of mining.

“Exploration, geophysics, elector-magnetic data mining, revisiting old data. We brought in PhDs from Ireland to work with our, and one of the best local, geologist teams. N$14 million for the scoops which operate remotely underground, our bar scanning system, our world class stores management system. 62 000 parts for machine maintenance because we must always have spare parts ready. And our people, transferring skills to locals, as is the case with Sheron (Kaviua), our first female resource manager. We few ex-pats are working ourselves out of jobs because we want 100% Namibian employment,” he said.

Kaviua believes in shared vision; “to be the best underground mine in the world. Our values talk to this vision and we follow a change management process, showing people the end results, convincing us all to jump into and grab opportunities, to get excited. We are already almost a paperless operation,” said the current technical services manager.

Underground

Glaspool said: “We are firstly an underground mine. For many years, we have been the only underground mine (in Namibia). For underground mining you need mining engineers with underground experience, geologists, geotechnical engineers that are sometimes known as rock engineers, ventilation engineers and you need amazing operators and artisans that operate and maintain the various equipment and machines that are unique to underground mining.”

Regarding the information communication technology (ICT) Horn explained that a coaxial cable network is intended for communication between 125 m underground to depths of about 650 m and that roll-out of full WiFi underground will be completed over the next year, including application of smart devices. “It is an internal network, not accessible from outside, for the protection of internal data,” he added.

Horn elaborated: “From real-time monitoring to seamless integration of all mining related activities and ‘smart equipment’. Most of our equipment is already ‘smart-ready’ but requires the backbone of communication, which is the WiFi network.” Horn added; “we have started with machine learning to assist in our blending analytics. All our data goes to a data-lake, hosted in the cloud. From the data-lake, data is extracted and algorithms written to automate the current steps that our geologists and mining engineers are taking to arrive at the best blending ratio. Machine learning automates this level of thinking. Artificial intelligence is the next logical step, but not yet used.”

According to Horn , “we cannot wait for the arrival of a new production drill which will be fitted with the latest technology to ensure we do semi-autonomous drilling and know exactly where in the three-dimensional space, a production hole is drilled. Combined with the first underground drone, we will be on the forefront of dilution control for underground mining. We will also be introducing semi-autonomous vehicles. This means, that some of our operators of equipment will be physically removed from the vehicle and operate it from a remote station. This unlocks great opportunities for people who previously were excluded due to the physical demands of being an operator.”

RP2.0

This is ‘RP2.0;’ the vision of what Rosh Pinah Zinc wants to become. According to Horn, the ambitious project focuses on four main areas; underground expansion by means of a new surface decline to deeper areas, underground paste filling for increased safety, expanding the surface plant with a new mill and flotation circuit, and modernisation and digitization. Mining will go down to about 750 m below the surface, he said.

“This will result in increasing production capacity from the current about 2000 tonnes per day (tpd), ip to 3200 tpd,” he said. “We have just completed the Full Bankable Feasibility Study in July and are looking forward to board approval towards the end of this year,” he added. Earlier this month he said, “we are currently engaging with various potential financiers for the project. In addition to this all permits are in place and negotiation with Nampower for additional power supply is well advanced.

The national electricity utility is under increasing pressure to supply power to southern mining project and on April 7, Rosh Pinah announced it had entered into a 15-year renewable power purchase agreement with Emerging Markets Energy Services Company (EMESCO) for the supply of solar power to the Rosh Pinah mine. The Company has previously committed to achieving an overall Green House Gas (GHG) emission reduction target of 25% by 2025 from its 2018 baseline. This agreement with EMESCO is anticipated to deliver 30% of Rosh Pinah's power requirements during the life of the agreement and reduce GHG emissions level by 6%, according to Trevali’s latest announcement.

Work safe

Horn pointed out that the 18-to-24-month project phase will see temporary employment will peak to about 200 people. “Once the project is complete there will be a marginal increase in permanent employment. For the mining part, we will be making use of bigger trucks and for the plant, we will have a bigger mill. The new paste plant will also unlock new job opportunities as this will be a new activity for the mine. But all in all, despite production going up by nearly 86% it does not mean we will be doubling up on equipment, simply using bigger equipment and better technology,” he said.

Horn adds that: “We are making great strides in safety and health. Over the past 5-6 years, we have seen our improvement in the all-injury frequency rate coming down by at least 10-20% year on year.

“The answer lies in the seamless integration of all work activities. Call it precision planning and execution. If you know exactly what each person must do during his or her shift, and can guarantee that you have provided all the training and equipment and safe work area for the task, combined with the acknowledgement from the person that this is in fact the case, you will be very close to guarantee a person’s safety. We have implemented a system, which is data driven and pro-active, to indicate where we are on this journey. In some areas and tasks, it is as high as 98%.”

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Namibian Sun 2024-11-23

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