Tag Archives: S11D

Miners need flexible solutions to meet decarbonisation goals, Worley’s Russell says

The unique challenges the mining industry will face over its 30-year journey to decarbonisation are still being unpacked as it decides how to use enabling technologies and solutions, according to Nicholas Russell, Senior Mechanical & Mining Engineer at Worley.

“The journey to net-zero requires flexibility,” he said. “And we need to incorporate that flexibility from the very beginning.”

This, according to Russell, has seen an increased focus on collaborative solutions across the mining value chain, including the re-emergence of 70-year-old technology.

In-pit crushing and conveying (IPCC) works by crushing ore and waste material in an open-pit and using conveyors to transport the material to the process plant and waste dumps respectively.

While IPCC is not new, miners often associate it with rigid, inflexible mine plans that struggle to meet changing market demands, he said. “However, an IPCC system is no longer just a fixed asset. Flexibility and sustainability in operations is possible through design innovation, tailored equipment specification and automation.”

One of the new ways that IPCC can be implemented is by using a combination of relocatable and mobile conveyors in tandem with a mobile, truckless system. This sees a shovel dumps material into a moveable sizing rig that loads the automated conveyor fleet.

“Much like irrigation sprinkler machines, the system operates in parallel, or pivot, and a combination of different length hoses and pipes connect it back to a fixed point, which in this case is the process plant,” Russell said. “By increasing the reach of the system, multiple combinations of bench level, mine direction and pass widths can be considered and optimised.”

In one study, an overburden truck fleet that moved material from the mine face to the top of the in-pit dump was replaced with an IPCC system. The haulage energy was reduced by 63% and 3.5 Olympic swimming pools of diesel each year could be replaced with renewables for each shovel swapped over, according to Russell.

Providing flexibility for minimum viable projects

Alternatively, as the mine face moves, a relocatable IPCC system can move with it.

“Trucks powered by renewables complete small distances to a crusher which is moved periodically, with conveyors used for the rest of the journey to the plant,” Russell explained. “While both options give the flexibility to change mining locations, this option provides the energy efficiency and cost-effectiveness of conveyors while benefiting from the flexibility of a truck system.”

Flexibility is especially useful for miners establishing sites with “minimum viable capital”, according to Russell.

“Miners can start with a small truck fleet and minimum fixed plant, relocating the crusher and conveyor as and when required,” he explained. “This is a key advantage because it helps achieve project specific goals through different mine sequences to enhance an operation’s sustainability.”

Powering mines with renewable energy

Powered by electricity ‘from the grid’, IPCC can be an energy efficient option for miners. It gives miners the flexibility to choose renewables to power their site, including the energy used for the mass material movement from the mine face to the process plant and waste dump.

Worley and its consulting business, Advisian, has helped a number of mining companies assess and develop green energy supply partnerships, Russell explained.

This has included the analysis, assessment and guided procurement of Gold Fields’ Agnew Hybrid Renewable Energy Microgrid, which included 18 MW wind, 4 MW solar, 13 MW/4 MWh battery and 21 MW gas/diesel. As the largest hybrid renewable energy microgrid in Australia, it has the capacity to provide the mine with up to 85% renewable energy, with reliability in excess of 99.99%, Worley said.

Enhancing an IPCC system with bulk ore sorting technology

Nicholas Russell, Senior Mechanical & Mining Engineer at Worley

“As miners seek to get more from less, IPCC can be enhanced with ore sorting mineral sensing technology supplied by NextOre,” Russell said.

NextOre, a joint venture between the CSIRO, RFC Ambrian and Worley, is a bulk ore sorting technology that allows miners to sort and evaluate ore at high capacity, maximising recovery and delivering higher grade and lower tonnage mill feed, he explained.

“It can be easily retrofitted to IPCC conveyors, and measure everything on the belt,” he added. “The option also exists to increase grade while maintaining throughput on existing systems, maximising metal recovery through the entire system assuming upstream and downstream facilities can be de-bottlenecked.”

By improving sorting efficiency, and processing a better material grade, water and electricity consumption per tonne of ore mined is reduced, while the data from the sorting process can be used to learn more about what is coming out of the ground as it’s mined, with assumptions verified in real time.

IPCC in action

One of the world’s largest iron ore mines in Brazil, S11D (pictured, photo courtesy of Vale), is a notable example of how new IPCC technology is enhancing sustainability and protecting people and the environment.

For this project, Worley proposed a truckless mine – “the first of its kind”, Russell said.

The system uses mobile crushers and conveyor belts to replace traditional trucks, consequently reducing diesel consumption by approximately 70%, according to mine owner Vale. The system also allows the miner to process waste in existing industrial areas, moving it away from environmentally sensitive ones to further reduce the project’s environmental impact.

“In designing the project, the team’s biggest challenge was not only rethinking the mine plan and how the technology could be used on the site, but also re-evaluating the role people play in executing the concept,” Russell said. “It’s critical to re-educate technicians and engineers to equip them with the skills needed to work with these technologies safely.”

Russell believes technologies like IPCC will help miners meet their decarbonisation commitments, however no individual technology can solve the challenge.

“To focus solely on the benefits of the equipment and disregard the mine demands is a short-term solution to a long-term challenge,” he said. “If miners are to meet sustainability goals, they need flexibility, collaboration and a holistic approach to implementing new technology that starts at the mine plan.”

Nick Russell is due to speak at IM Event’s IPCC 2022 event in Mexico, on April 28-29, 2022, presenting a paper titled: ‘Fully mobile IPCC/truckless mining: lessons learnt’. Click here for more information on the event.

Vale looks for increased operational flexibility with S11D iron ore expansion plan

Vale is to increase the capacity of its S11D iron ore operation, in Canaã dos Carajás, Brazil, after its Board of Directors approved the implementation of the Serra Sul 120 project.

The $1.5 billion Serra Sul 120 project will see the S11D mine-plant capacity increase by 20 Mt/y to 120 Mt/y. Start-up is expected in the first half of 2024, Vale says.

The project includes the opening of new mining areas, the duplication of the long-distance conveyor, the implementation of new processing lines at the plant and the expansion of storage areas, among other measures.

“The Serra Sul 120 project will create an important buffer of productive capacity, ensuring greater operational flexibility to face eventual production or licensing restrictions in the Northern System,” Vale said.

The $385 million investment to duplicate the existing long-distance conveyor, in addition to providing flexibility, also aggregates important elements for the reduction of operational risks, adding reliability to the system, according to the company. The existing long distance conveyor is part of a major in-pit crushing and conveying system at the mine. It could see Vale’s Northern System capacity rise by 20 Mt/y to 260 Mt/y.

“The expansion of the mine-plant capacity and the development of additional logistics capacity are important steps for the iron ore volume growth, the maximisation of margin and the flight-to-quality optimisation,” the company said.

With the anticipated investment for Serra Sul 120 and the delay in the execution of projects in 2020 due to the COVID-19 pandemic, Vale says it will, in due course, revise and update its investment guidance for 2021, currently at $5 billion, and in the period between 2022-2024, with an average of $4.5 billion.

Vale looks to smart meters for power cost, GHG emission reductions

To reduce operating costs and greenhouse gas emissions, Vale is investing BRL20 million ($4.9 million) into the implementation of a smart energy management system to improve equipment performance and process automation across its production chain – from mine to port.

The system, known as SmartEnergy, should lead to the installation, by 2021, of 2,000 intelligent electric power meters at 57 of the company’s operating units and large equipment in Brazil – for example, in ore grinding circuits, long-distance conveyor belt systems and pumping systems.

The smart meters reduce production losses through continuous evaluation of the quality of power and identification of the causes of failures in power supply. Tests using this technology in two mines have saved BRL90 million per year, according to Vale, eliminating equipment shutdowns due to incorrect activation of the “electrical protective system”.

According to Vale’s Energy Efficiency Project Coordinator, Renato Arantes, smart meters can accurately detect voltage and electric current variations. These meters also register the power consumption and submit data to SmartEnergy, which enables interactions with several enterprise systems, including management of energy efficiency programs, among other functions.

Arantes said: “Often, the electrical protective system shuts down important equipment or processes due to electric power fluctuations that could be tolerated without adding any risks to operations. These small interruptions affect productivity as energy is wasted in restarting the equipment and processes as well as resuming normal operating capacity, not to mention the impact on production and increased CO2 emissions.”

SmartEnergy IT Coordinator, Laysa Mello, explained that the system will standardise the data generated by smart meters to analyse the energy use across the company.

“This standardisation enables better planning of energy consumption and demand in all operations, offering unprecedentedly higher data availability and accuracy,” she said. Although it is an off-the-shelf software already available on the market, SmartEnergy had to be customised for Vale’s needs, the company said. A team of 65 employees was trained to operate the system already deployed in mines in Pará and Minas Gerais and at the Ponta da Madeira port complex, in São Luís (Maranhão).

In 2017, Vale tested the smart meters at the S11D iron ore mine (pictured) and the Salobo copper mine, in southeastern Pará. Salobo saw a reduction of 107 hours of unexpected production shutdown caused by power quality issues, which translated into a production increase of 1.2 Mt/y compared with 2017 and 2018.

In the case of S11D, 18 hours of production shutdown were avoided at the plant, resulting in an increase of 130,000 t in annual production. By the end of 2019, more than 100 smart meters at S11D were connected to SmartEnergy, and, in 2020, Vale plans to deploy this equipment worldwide.

In an intermediate scenario over 10 years, the company expects to save BRL920 million worth of electric power through the installation of smart meters and process management automation in plants in Brazil and abroad. The aim is to reduce greenhouse gas emissions by 120,000 t/y, equivalent to the emissions – in terms of power consumption – of 14,400 average homes. Variables considered in this calculation included the cost of electric power; iron ore, nickel, and copper prices; and Vale’s own production.

In the long run, the project will also focus on reducing other fuels used by Vale, such as diesel, natural gas, and the bunker fuel used in ore carriers. “That brings an even greater potential to reduce emissions.”

At a December meeting with investors in New York and London, the company announced a long-term goal of neutralising CO2 emissions from its operations by 2050 and revised its emission reduction goal by 2030 to comply with the Paris Agreement. The percentage decrease will be announced in the first half of 2020.

Vale exploring dry stacking/magnetic separation to eradicate tailings dams

Vale has confirmed a Reuters news report from last week stating that it would spend an additional BRL11 billion ($2.5 billion) on dry iron ore processing over the next five years.

The company said it has invested nearly BRL66 billion installing and expanding the use of dry processing, using natural moisture, in iron ore production in its operations in Brazil over the last 10 years and it would carry on this trend.

“By not using water in the process, no tailings are generated and, therefore, there is no need for dams,” the company said, added that about 60% of Vale’s production today is dry, and the goal is to reach 70% in the next five years.

Dry processing is used in the mines of Carajás, Serra Leste and the S11D Eliezer Batista Complex (pictured), in Pará, Brazil, and in several plants in Minas Gerais. In Pará, in the Northern System, about 80%, of the almost 200 Mt produced in 2018 was through dry processing. The main Carajás plant, Plant 1, is in the process of conversion to natural moisture: of the 17 plant processing lines, 11 are already dry and the remaining six wet lines will be converted by 2022.

Serra Leste’s treatment plants, in Curionópolis, and S11D, in Canaã dos Carajás, also do not use water in ore treatment, according to Vale. In S11D, for example, the use dry processing, using natural humidity, reduces water consumption by 93% when compared to conventional iron ore production.

In Minas Gerais, dry processing increased from 20%, in 2016, to 32%, in 2018. Today, this type of processing is present in several units, such as Brucutu, Alegria, Fábrica Nova, Fazendão, Abóboras, Mutuca, Pica and Fábrica. “Over the following years, the objective is to roll it out at other locations in Minas Gerais, such as the Apolo and Capanema projects, which are currently under environmental licensing,” the company said.

Vale said: “Dry processing is linked to the quality of the iron ore extracted from mining. In Carajás, as the iron content is already high (above 64% Fe), the ore is only crushed and sieved, so it can be classified by size (granulometry).

“In Minas Gerais, the average content is 40% iron, contained in rocks known as itabirites. To increase the content, the ore is concentrated by means of wet processing (with water). The tailings, composed basically of silica, are deposited with water in the dams. The high-grade ore resulting from the process can then be transformed into pellets at the pelletising plants, increasing the added value of the product.”

The mills that operate dry processing in Minas Gerais depend on the availability of ore with higher levels – about 60% Fe – still found in some mines in the state. “In order to achieve the necessary quality, and be incorporated into Vale’s product portfolio, it is necessary to blend with Carajás ores, carried out at Vale’s distribution centres in China and Malaysia. The process allows Vale to offer excellent quality ore which can be tailored to meet the needs of our clients,” the company said.

The blending of the product with natural moisture does not eliminate the need for humid concentration of the low-grade itabirite used in the production of pellets. However, to reduce the use of dams, Vale plans to invest approximately BRL 1.5 billion on dry stacking technology in Minas Gerais between 2020 and 2023. This technique filters and reuses waste water and allows the latter to be stored in piles, thus reducing the use of dams. The goal is to achieve up to 70% of the waste disposed in the coming years, but success depends on the improvement of technology and external issues, such as environmental licences, Vale said.

“Today, Vale doesn’t have a dry stacking operation that can deal with the production quantity especially in a region with high rainfall indices, such as the Ferriferous four-side, in Minas Gerais. The available dry stacking technology is used on a small scale around the world – up to 10,000 t/d of tailings produced – in desert regions or with low rainfall. In Minas Gerais, Vale’s tailings production quantity is, on average, 50,000 t/d per unit,” Vale said. In 2011, the company developed a pilot project on the Cianita stack in Vargem Grande, after an investment of BRL100 million.

The studies were completed in 2018 and the technicians evaluated the geotechnical behaviour of piles under rainy conditions. The next tests will be applied on an industrial scale at the Pico mine in the municipality of Itabirito, Vale said.

“Another solution that has been studied is the dry magnetic concentration of iron ore based on the innovative technology developed by New Steel, a company acquired by Vale at the end of 2018 for BRL1.9 billion,” Vale said. “The dry magnetic concentration eliminates the use of water in the concentration process of the low-grade ore, which disposes the waste generated in sterile piles, similar to what happens in dry stacking. This technology, however, is in the industrial development stage and is not yet ready to be applied on a large scale.”