At the recent Bank of America 2023 Smart Mine 4.0 conference, Donovan Waller, Anglo American Group Head of Technology Development, provided an in-depth overview of ongoing projects under its FutureSmart Mining™ banner, broadly referring to its innovation-led approach to sustainable mining.
He covered five areas of interest: the African renewable energy ecosystem; the nuGen™ Zero Emission Transport Solution is led by engineering partner First Mode; Coarse particle recovery (CPR); Hydraulically dewatered stacking; copper leaching; and microwave-based preconditioning.
He then concluded with two tantalizing glimpses of earlier stage projects – namely “Haulage Redefined”, where he shared an image of what appeared to be a machine along the lines of a fully mobile MMD Surge Loader, working with smaller class, cables , autonomous and probably battery electric trucks. He also shared some images of possible intelligent logistics concepts of the future.
On the energy front, Anglo American last year in South Africa partnered with EDF Renewables, creating Envusa Energy, and announced the first 600 MW of wind and solar projects, designed to shape the development of a wider regional ecosystem for renewable energy (RREE) that is expected to generate 3-5 GW in the next decade. It has reached commercial terms for two wind farms of 140 MW each and one solar farm of 200 MW in the Eastern Cape. It is aiming for financial close in the third quarter so that these sites can begin construction immediately. Anglo is also developing 2 large solar installations at our mines in Sishen and Mogalakwena.
I AM has already published extensively on the next topic of the nuGen™ Zero Emission Transport Solution – the prototype of which the truck DT74 successfully operated for a year in Mogalakwena, during which time it was introduced into a mixed commercial fleet, including ore and waste transport operations , in addition to diesel vehicles, with more than 1,200 operating hours.
Subsequently, in the four more downstream areas – on CPR, after its construction in 2021, the coarse particle recovery unit at Chile’s El Soldado copper mine was successfully handed over to operations, following energy unit consumption targets were surpassed and a 16% increase in copper production without the need for additional energy. Waller: “It beat every metric we set up for it before we started the project.”
The innovative flotation process, which allows material to be ground to a larger particle size, enabling early rejection of bulky waste and greater water recovery, has already begun production of bulky waste used in the nearby pilot for hydraulically dewatered stacking (HDS). ).
A large-scale CPR installation has been built at the Mogalakwena North concentrator
A large-scale CPR installation has been built in the Mogalakwena North concentrator and is expected to start up at the end of 2023. Construction of a full CPR plant in Peru’s Quellaveco to treat flotation waste began in July 2022 and commissioning is scheduled for late 2023. Future resuscitation plans include Los Bronces, Minas-Rio and Collahuasi. “CPR has not only demonstrated its value, but like many of our other technologies, it provides a strong platform to build upon.”
There was a lot of HDS advancement that Waller says has been successfully demonstrated at the El Soldado mine. “HDS was developed after the Brumadinho disaster because our engineers hypothesized that the fine-free sand available from CPR (and readily available at many tailings) could be used to build a three-dimensional drainage system for rapidly unsaturated hydraulic deposited residues.” The idea has been iterated, developed and developed into a stable residue stack that can dewater (and desaturate) in days and weeks rather than years and decades.
The large-scale 150,000 m3 capacity demonstration facility at El Soldado uses fine-free sand from the El Soldado CPR plant, the largest such plant currently operating at a base metal mine. Waller: “Initial results show over 80% water recovery, but more importantly, a final stack with reduced saturation levels, significantly reducing both the likelihood and impact of liquefaction.”
In June 2023, Anglo American started a second trial at the Mogalakwena mine in South Africa, focusing on the application of HDS in an existing facility. “This is important as existing facilities can in some cases be reconfigured mid-life to take advantage of HDS. We are currently assessing the possibility of this at Los Bronces.” He added that commercialization and acceleration of development of the technology has begun and agreements with geotechnical designers are expected to be signed in the coming months.
Waller continued: “Discussions with mining companies are progressing and we are targeting at least two joint development trials to begin in 2024. We are proposing a jointly licensed approach that further accelerates learning and ensures that each application improves and as a result we can quickly deploy this technology, where appropriate, to demonstrably reduce residue management risks – changing the conversation from a conversation about mitigation in a conversation about opportunities; where the land used for residue storage can be quickly and efficiently reused and benefit all stakeholders.”
Then it leached, where Waller said there had been developments in the works over the years “that show significant advantages over what we’ve seen from others so far.” Anglo’s SandLix™, it says, unlike others, takes into account three elements: particle size, temperature and chemistry. The method unlocks metal recovery from low-grade, low-intensity refractory sulfide ore.
“Primary copper ore results show a recovery of more than 70% in half the time of traditional leaching methods. We will eventually see this technology replace conventional concentrator circuits and deliver metal more responsibly – and at about half the water and energy intensity absorbed. We have shown excellent results in column tests up to 18 meters and our team is currently working on parallel work programs to scale up the technology. We are actively accelerating this work and are currently negotiating agreements with partners to explore commercial outcomes.”
Testing microwave rock preconditioning in a surface quarry
Moving on to newer concepts – he also discussed his work preconditioning ores with microwaves to weaken them for both stone cutting and downstream reduction processes. Waller: “In particular, focused and controlled microwave energy can cause thermal stress that fractures the rock mass and reduces its inherent strength. The implication is the possibility of accelerated mining and development rates, hopefully enabling faster access to ore bodies and allowing them to be mined more quickly.
He said it has been testing application methods and effect on in-situ ores in both underground and opencast mines in recent years. “We are currently testing a production cutter in a quarry and if successful we will install a first generation microwave conditioning system in a production environment at an Anglo-American site in 2024.”
It also provided a tantalizing glimpse of the kind of future transport concepts Anglo is eyeing. Waller said mining has used trucks and shovels for the past hundred years — probably the most successful combination of mining technology ever. “I attribute their success mainly to flexibility, reliability and scalability. We stepped on this hallowed ground and allowed ourselves a blank sheet of practice to address the shortcoming of mining trucks, namely: cost, speed and energy consumption.
By adjusting the basic operating assumptions of payload and working with vehicle designers and tire manufacturers, Anglo says it has reimagined weight distribution, symmetry, modularity and design using only off-the-shelf components. “We surprised ourselves and created a unique alternative value proposition, using the vehicle as a sensor, reducing energy consumption by almost half, increasing speed and effectiveness, all at a lower cost. While still in its infancy, we have the ingredients for a future mining system focused on precision.”
Finally and in parallel – the work on intelligent logistics seeks to redefine material movement, efficiency and scalability. “Using linear motor technology in combination with new, powerful and cost-effective distributed computing technology, we have developed the individual elements of a scalable, self-configuring mine logistics system capable of handling typical material movements from and logistics requirements to a mine. ”
This new system offers high capacity (~40 Mt/y) with a very small footprint; energy per ton-kilometer of material moved is an order of magnitude lower than transport systems; it is modular, flexible, easy to install within changing mining requirements; it allows very precise control of small strategic mining units to and from multiple destinations; and it has the ability to travel both horizontally and vertically.
He added, the result stimulates new thinking for both underground and surface mine designs. With both this and the previous technology on display, we are looking for partners to continue the development and construction of the first pilot systems to validate systems suitable for mines.”