Tag Archives: chromium

STEINERT sensor-based sorting solutions helping Ferbasa adopt ESG practices in Brazil

The use of sensor-based sorting (SBS) technology is allowing Companhia de Ferro Ligas da Bahia (Ferbasa) to avoid unnecessary processing by separating a fraction of the high-grade material from the metallurgical process feed in advance, a recent case study from STEINERT has revealed.

Ferbasa is in Ipueira, a municipality in the state of Bahia in the northeast of Brazil. It operates one of the largest chromite mines in Brazil and is considered a pioneer in the use of SBS technology, STEINERT says. The company processes chromite obtained from an underground mine, with the extracted material pre-concentrated using sorting technology that employs sensors, and is later used in the production of specialised steel alloys.

With a processing capacity of 12 Mt/y, the company has been using sensor-based sorting for 10 years, in a completely dry process that separates waste from high-grade chromite.

Eriberto Nascimento Leite, Mining Director at Ferbasa, says the ability to avoid unnecessary processing by separating a fraction of the high-grade material from the metallurgical process feed in advance through the use of SBS removes the requirement for any additional processing. In that way, particles which are not economically viable are eliminated from the process beforehand with only valuable material undergoing the follow-on concentration steps.

At Ferbasa, the use of SBS technology has enabled an increase in production, in addition to reducing costs in the subsequent processes, such as comminution and the use of inputs, such as reagents.

“Today, at Ferbasa, sensor-based sorting technology helps us adopt ESG practices, reducing waste, maximising production efficiency and contributing to the conservation of natural resources,” Nascimento says.

Nowadays, it is not only the mined ore that is processed, but also the stockpiles, which contain considerable amounts of chromium. The treatment of these stockpiles is only possible thanks to process automation and its high-capacity levels, which reach up to 180 t/h. Stockpile treatment has the potential to increase productivity in the mine. In terms of resource use, there is potential to reduce the consumption of water, energy and chemical reagents primarily because SBS is a dry separation process, unlike other pre-concentration processes such as dense media separation.

Ferbasa has always used a pre-concentration process with the aim of separating lump ore, which has a high chromite content, from the low-grade ore that goes to the concentration plant. However, this used to be a manual separation process. Bartolomeu Fonseca, the former Processing Manager at Ferbasa, discovered an article about sensor-based sorting technology from STEINERT. In 2012, he prepared material to be sent for tests at STEINERT’s Test and Development centre in Germany, and these were deemed successful.

A STEINERT KSS XT L in the chromite preconcentration setup

Ten years ago, when the first equipment was being installed, Ferbasa’s employees were sceptical about its capacity to support the adverse conditions in the mine. This is why STEINERT Latinoamericana, a subsidiary of STEINERT GmbH in Germany, offered a “try and buy agreement”. Over the years, the equipment’s high level of durability has been verified, resulting in the first unit still being in operation today, with a total of 34,000 hours of runtime.

“Looking back, it was not easy to apply the technology, but I decided to move forward because I believed that the technology could be effective,” Fonseca says. “Now, already retired, I am very proud of the legacy that I have left to the company. I had the full support from the mining director at that time, Wanderley Lins, but it was my responsibility to make it work.”

In 2014, during the commissioning of the first sorting system, a STEINERT XSS-T, STEINERT Latinoamericana started a partnership with Ferbasa.

Alonside this, STEINERT currently has a team of 30 collaborators who serve several mining clients in Latin America, in addition to having a test centre near the office in Brazil, enabling tests to be carried out with more convenience and efficiency for local clients.

Ferbasa started operating its first equipment in 2014. By 2019, it already had six units installed for the processing of run of mine and low-grade stockpiles.

The production benefits from flexibility of the sorting systems, which generate waste material, pre-enriched material and high-grade material. The processing capacities are up to 120 t/h for particles of 1- 3 in (25-76 mm), reaching up to 180 t/h for particles from 2-5 in. In terms of the sizes processed, the combination of sensors facilitates the separation of particles up to 5 in; a feature that, STEINERT says, reinforces the robustness and efficiency of the equipment for the detection and ejection of extremely coarse particles. In total, recoveries reach values of up to 90%, with upgrades of up to 1.5-3 times the feed levels.

Currently, Ferbasa applies SBS technology to process 100% of their run of mine, using two units from STEINERT, the STEINERT XSS T and STEINERT KSS | XT L, in a two-step process. In the first step, waste material is rejected, and, in the second, pre-enriched and high-grade materials are generated. The high grade-material meets the content specifications to be sent to the metallurgic plant, while the pre-enriched material is sent to another plant to follow other concentration procedures. Furthermore, the technology is applied in the processing of low-grade stockpiles, using two STEINERT KSS | XT L units – which combines the X-ray transmission sensor with three other additional sensor options (Induction, 3D laser, and Colour) – in two steps to separate waste, pre-enriched material and high-grade material. As a result, the low-grade stockpiles are processed in an economically viable way and with high sustainability gains.

Canada Nickel progresses carbon capture and storage test work for Crawford

Canada Nickel Company Inc says the latest test work on material from its Crawford project, in Ontario, Canada, supports the incorporation of carbon capture and storage into the develoment.

The company has devised an In-Process Tailings (IPT) Carbonation process, which, it says, is a novel method for accelerated carbon capture and storage that it believes has transformative potential.

The latest test work conducted at Kingston Process Metallurgy (KPM) confirmed that existing process streams can be used for IPT Carbonation, which the company believes should allow it to be timely and cost effectively engineered and incorporated into the project flowsheet.

Crawford is hosted in ultramafic rock, which naturally absorbs and sequesters CO2, according to the company, with the potential to actively capture and sequester carbon being a key consideration in Canada Nickel’s acquisition of the 42 sq.km of target ultramafic rocks in the Timmins area.

Canada Nickel has developed an active process that uses tailings as generated in the milling process and injects a concentrated source of CO2 for a brief period of time. This process, IPT Carbonation, fixes CO2 geologically while the tailings are still in the processing circuit, rather than after they have been finally deposited.

The company believes that, given its relative simplicity, this process could be scaled up with availability of concentrated (rather than atmospheric) sources of CO2, with the CO2 potentially delivered by downstream processing of Crawford concentrates, a wide range of industrial processing activities, green hydrogen production, or carbon capture facilities.

Canada Nickel said: “The process demonstrates the potential to produce NetZero Nickel™ and NetZero Cobalt™ for the electric vehicle industry, NetZero Iron™ and chromium for the stainless steel industry and generate substantial carbon credits during the process. The company believes that the need for a concentrated source of CO2 for this process and the substantial CO2 capture and storage capacity potential of its ultramafic land position could form the basis for an entire Zero Carbon Industrial Cluster in the Timmins-Cochrane region.”

The latest results from further lab-scale testing at KPM confirmed that a blend of tailings expected to be produced by Crawford and thickened to an expected operating tailings density could be successfully carbonated with the IPT Carbonation process, the company said. This is a significant result to demonstrate the process at higher solids densities as the pulp density and the tailings residence time will be a key driver of the process capital and operating costs, it explained.

The testing also attempted to understand what ultimate carbon capture potential is possible and the test resulted in 37 t of CO2 captured per tonne of nickel – 34 t of that amount was captured within 25 hours. The 37 t figure is believed to represent a potential maximum and there is no certainty that such amount could be achieved in commercial operation, the company said.

As a result of these results, the integrated feasibility study for the project is expected to be delivered in the June quarter of 2023. This delay, the company says, has no impact on the overall timeline to production, with Canada Nickel continuing to target receipt of permits by mid-2025 with construction to follow.

Mark Selby, Chair and CEO of Canada Nickel, said: “We believe the Crawford project has the potential to be a case study in how critical minerals are developed in Ontario and Canada. Crawford is poised to support the energy transition through the large-scale production of critical minerals, including nickel and cobalt, and to become the sole North American producer of chromium, while also supporting the country’s climate objectives through large-scale carbon capture and storage.”

The company believes the successful incorporation of IPT Carbonation could also potentially allow a portion of its project capital expenditures to become eligible for the carbon capture and storage refundable investment tax credits of 37.5% to 60% from 2022-30 and 18.75% to 30% from 2031-40 announced in the 2022 federal budget documents in Canada.

Selby added: “We look forward to continuing our positive momentum in 2023 as we complete this integrated feasibility study for Crawford, continue to successfully advance the Crawford permitting process, work with our recently appointed financial advisors to advance its overall financing package and aggressively advance our recently acquired Texmont property with its potential for near-term production. We are also excited by our successful tests of the regional exploration potential at Reid, Deloro, Sothman and Reaume which, as they are hosted in the same mineralisation as Crawford, offer the same potential for integrated carbon capture and storage – setting the stage for a Zero Carbon Industrial Cluster in the Timmins-Cochrane region.”

ValeOre Metals considering Platsol, Falcon separator, Steinert ore sorting for Pedra Branca

ValeOre Metals Corp’s Pedra Branca platinum group element (PGE) project, in north-eastern Brazil, looks increasingly like leveraging the Platsol™ high temperature pressure leaching process judging by the latest test work.

Metallurgical results from sample material collected from outcrops at the Trapia and Curiu deposits areas at Pedra Branca for two preliminary Platsol tests conducted at SGS Lakefield, Ontario, have shown recoveries of 93.4-93.6% for palladium and 95.3-95.7% for platinum were achieved.

The company now plans two additional Platsol tests, to be performed by SGS, to determine the effects of adding elemental sulphur to the autoclave to optimise conditions required for PGE and gold recoveries, it said.

Platsol is a high temperature (>200°C) pressure leaching process designed to recover PGEs, gold and base metals. It has been shown to be particularly effective with PGE ore feeds characterised by high concentrations of chromium and low concentrations of sulphide, much like Pedra Branca, according to ValeOre Metals. The PGEs and gold are solubilised as chloro-complexes by the addition of chloride salt to the autoclave, while base metal sulphides are oxidised to form soluble metal sulphate complexes. The precious metals can be recovered directly from the autoclave discharge slurry by carbon absorption, or by precipitation with sulphide ions.

Platsol consists of standard, proven traditional technologies that are in use in mines around the world, according to the company.

The Platsol tests are part of a comprehensive mineralogical evaluation ongoing at SGS to characterise the speciation of palladium and platinum in Pedra Branca mineralisation to guide future process optimisation initiatives.

As part of this, the company is continuing with Falcon Ultrafine gravity separation test work as a potential pre-concentration circuit to upgrade feed material and improve mass pull.

The company has also initiated hot cyanide leach test work to assess the recovery rates of palladium, platinum and gold in a cyanide leaching process, and will shortly commence shipment of 100 representative chip samples from historic drilling at the Esbarro deposit to Steinert’s facility in Minas Gerais, to evaluate the potential of sensor-based ore sorting test work.

ValOre’s Chairman and CEO, Jim Paterson, said: “The pace of success at Pedra Branca has increased dramatically in the last three months, including today’s release of PGE metallurgical recovery rates of in excess of 93% for palladium and 95% for platinum using the Platsol process.

“Together with an aggressive property-wide exploration program, we are now focused on rapidly optimising the conditions, procedures and processes to further maximise the upside potential of the Pedra Branca project.”

Liebherr crawler excavators proving their worth in South Africa chromium mine

After more than 1,000 operating hours, three Liebherr R 920 crawler excavators are still exhibiting the fuel efficiency, manoeuvrability and hydraulic performance that convinced mining company KEDASE to buy the equipment, the original equipment manufacturer said.

KEDASE, based in Boshoek, South Africa, purchased three R 920 crawler excavators from Liebherr in 2016. They are used for trenching, pipe laying and the feeding of a screen in a chromium mine in the country.

With an operating weight of 21 t and equipped with a Stage IIIA/Tier 3/CHINA III engine with an output of 110 kW/150 hp, the R 920 crawler excavator was developed specifically for these types of applications, according to Liebherr. For KEDASE, the machines have been configured with a 5.7 m boom, a 2 m stick and a 1.15 m³ bucket.

“The R 920 concept is based on the standard European models with high levels of reliability and increased productivity combined with low fuel consumption,” Liebherr said. “Launched onto the market at Bauma 2016, the R 920 is accompanied by a revamp of the range of 20-25 t crawler excavators.”

In addition to the R 920 are the R 922 and R 924. The R 922 weighs 22 t and has an output of 110 kW/150 hp and the R 924 weighs 24 t with an output of 125 kW/170 hp. “These machines are aimed at less regulated markets like South Africa, South East Asia, Russia, China and India,” Liebherr said.

Since their arrival in 2016, the R 920 crawler excavators have met all expectations, according to the OEM.

“After more than 1,000 operating hours, these machines are currently used for nine to 12 hours every day with an average fuel consumption of only 15 l/h. The manoeuvrability and hydraulic performance, in particular, make the machines efficient on site. From the operator’s point of view, the R 920 is characterised by its speed, comfort, stability and performance: “I feel like I’m in a pickup”, one operator said.

Liebherr said the expectation is that these machines will keep performing over time and reach 15,000 operating hours.