TOMRA recently held a seminar on sustainable mining solutions and sensor-based sorting that, it said, addressed major challenges of the mining industry, including increasing pressure to be more financially streamlined and radically more efficient, while addressing environmental and sustainability concerns.
Sensor-based sorting (SBS) is proving to be an increasingly important tool both to formulate optimal solutions for greenfield projects and to help conquer challenges for keeping brownfields operations viable, converting the mining operation’s resource into value, according to TOMRA.
During this seminar at the Colorado School of Mines, TOMRA’s specialists were joined by guest speakers to examine all aspects of a sensor-based sorting operation with a broad range of topics including sorting technology, applications, plant design, test work and economic considerations.
The 62 participants came from all across the US and Canada, and included representatives from mining companies, engineering firms and students and professors eager to learn more about the applications and technology.
Corby Anderson, Harrison Western Professor at the Colorado School of Mines, opened the seminar with an introduction of recycling, recovery and sorting. The next talk focused on sensor-based sorting technologies and their applications, as well as highlighting fully operational SBS plants in the mining industry.
TOMRA’s Mathilde Robben explained the importance of setting objectives for SBS and the financial and technical aspects to evaluate.
“The most critical factors to consider when assessing the feasibility of sorting are throughput requirements, particle size and potential water usage, as well as the mineralogy of the ore,” TOMRA said, adding that having a clear understanding of where sorting can benefit in the process is paramount when planning to use this technology.
Test work is the best way to determine if SBS will work for an application, and TOMRA’s Chris Korsten explained the company’s test work philosophy to identify the best solution that will meet the mining operation’s specific conditions and objectives.
Guest speaker Erik Stepperud of Hazen Research, the industrial R&D company specialising in the mining, chemical, energy and environmental industries, shared his expertise in assays and interpretation of test results, while Craig Murray of the Saskatchewan Research Council spoke about testing and support services for projects using sorting technology.
Downstream impacts
When designing optimal sorting plants, it is critical to understand the necessary auxiliary components for materials handling, such as screens, washing and conveying, and where to place the sorter in the flowsheet to optimise the process and get the most out of SBS, according to TOMRA.
Particle size is critical to SBS, so designing optimal crushing and screening units is vital, and TOMRA invited expert speakers to cover these topics: Jörn Rohleder of Outotec, which specialises in designing leading technologies and services for the sustainable use of natural resources, discussed crushing design and Eli Cannell of Joest, a leader in vibration technology, elaborated on screening. Greg Black of Golden Eagle Technologies, meanwhile, covered the topic of dust extraction.
SBS can have a huge positive impact on the downstream operations of a flowsheet, as more waste is rejected from the process upstream. This means waste is not carried through the rest of the process, resulting in significant savings in energy, water and chemicals. A further benefit is the reduction of fine tailings that are environmentally challenging to manage.
The seminar was very well received, according to TOMRA, and achieved its goal of providing a pragmatic foundation on SBS projects. Genevieve Gosselin, Senior Technical Metallurgist at Agnico Eagle Mines, said, “The seminar gave us keys for the implementation of ore sorting in brownfields and greenfields mining projects”. Vera Gella, Metallurgist at BBA, said: “For us, the test work preparation and flowsheet design are most relevant to what we do every day and being able to quickly assess whether or not sorting is applicable to a given project. Like Jörn pointed out, if you pick the wrong crushing/SBS circuit design up front, it can drastically change the outcome of a project. It’s critical to think carefully about how to get the most out of your sorting circuit.”
It also raised awareness of aspects that participants may not have considered in the past. For Gosselin it was “how important the geology of the deposit is, and the need to evaluate this before starting bench and pilot scale testing”. Gella, on the other hand, was struck by the sustainability aspect, which is becoming increasingly important: “One of the things that we hadn’t thought about because our scope was focused on the economic tradeoff was the environmental impacts of SBS. The environment is becoming more and more of a focus for all stakeholders and will be a key driver for mining projects going forward.”