THE CHALLENGE: Transforming Compact Bauxite into a High-Quality Product
To ensure a competitive product, TGM faces environmental, social, and especially commercial challenges. The goal is clear: transform compact bauxite into a material with accepted calcium and aluminium content, to meet increasingly stringent market standards. With advancement in mining operations, the need for innovative technological solutions has become even more urgent.
In this scenario, the implementation of Sensor-Based Sorting (SBS) technology emerges as a solution to meet the market requirements. Previously, material classification was done through screening only, which resulted in the retention of anorthosite a more resilient lithology rich in iron (Fe) and calcium oxide (CaO) in the coarser fractions.
As the next step in the project’s development, the creation of a new, higher-value-added product was planned. The primary requirement defined was to ensure efficient impurity removal to reduce calcium contamination below 0.15%. Additionally, increasing the aluminium oxide (Al₂O₃) content range between 62% and 63% would be beneficial, as it would enable the production of a premium material.
To accomplish this objective, developing a beneficiation flowsheet for the screened material would be required. Conventional bauxite processing flowsheets involve stages such as comminution, magnetic separation, washing, dewatering, or flotation.
It was in this context that the partnership with STEINERT Latinoamericana was established, providing sensor-based sorting technology, also known as “Ore Sorting”, to the forefront of operations. Unlike conventional methods, Ore Sorting enables dry separation applying sensors that identify the ore’s composition in real time. This solution not only enhances product quality but also eliminates the need for water and tailings dams, promoting a more sustainable and efficient operation.
According to José Maurício, TGM's Planning Manager: "The application of Ore Sorter is crucial to meeting the requirements of specific markets, such as the refractory abrasives market, due to the strict standards regarding calcium oxide (CaO) content."
With this innovation, TGM not only enhances its competitiveness in the industry but also positions itself as a benchmark in sustainable mining, aligning with best environmental practices and the growing global demand for more responsible operations.
SUCCESSFUL PARTNERSHIP: Innovation and Concrete Results
The collaboration between TGM and STEINERT began in 2022 with testing to validate the technology’s efficiency. Samples were sent to the Testing Centre in Matosinhos, Minas Gerais, Brazil, where the STEINERT KSS | XT CLI equipment which are equipped with X-ray transmission, colour, 3D laser, and magnetic induction sensors to enabled precise material analysis.
In the first round of tests, using two tons of samples, +1” -4” (from one to four inches), the results were exceptional: a customized configuration for each material type, with a standout combination of X-ray transmission and 3D laser, ensuring highly efficient separation.
This initial success led to a second round of testing, focused on an even greater challenge: obtaining premium bauxite with high aluminium oxide (Al₂O₃) content while reducing contaminants such as silicon dioxide (SiO₂), hematite (Fe₂O₃), calcium oxide (CaO), and magnesium oxide (MgO), in a finer size fraction of +1” -2” (from one to two inches).
After fine-tuning the process, STEINERT’s technology demonstrated its full capability to:
- Reject particles with high iron content
- Significantly increase aluminium oxide (Al₂O₃) levels
- Reduce impurities to meet market standards
The second test confirmed the efficiency of XRT (X-ray Transmission) technology in removing contaminants, achieving the desired parameters (calcium oxide (CaO) < 0.1%) and reducing iron oxide (Fe₂O₃) contamination in the reject material, which showed levels between 7% and 22%.
TGM’s strategy for directing Ore Sorter products reinforces the zero-waste concept, enabling the production of high-value bauxite and the commercialization of reject material for various industries, such as cement, ceramics, and metallurgy. This expands both sustainability and the economic feasibility of the process.
“Bringing together the expertise of those who know the equipment with those who understand the process and the product allows us to identify the ideal operational limits and areas for improvement, facilitating collaborative work to optimize operational profitability and enhance the product”, says Alexandre Rosa, TGM's PCP Supervisor.
One of the improvements proposed by the STEINRET Latinoamericana team during the initial phase of the pilot plant was the use of object formation optimization technology on its software to improve particle recognition and ejection accuracy. This optimization helped counteract the effects of fines in the feed material while meeting the requirement to adjust the processed material’s particle size to +1/2” – 2” (half an inch to two inches). As a result, data accuracy increased, result variability decreased, and plant productivity improved significantly.
FROM THEORY TO PRACTICE: Industrial-Scale Implementation and Effective Gains
With the proven effectiveness of Ore Sorting, TGM acquired its first STEINERT sorting system, replicating the excellent laboratory results on an industrial scale.
TGM’s ore, derived from the leaching of anorthosite, contains high calcium levels, making separation a critical challenge. The use of X-ray transmission, which correlate the atomic density of the particles, proved to be the ideal solution for this scenario, enabling precise separation of bauxite from anorthosite and ensuring operational efficiency directly at the mine.
"By applying the sorter, we can leverage our production at the mining front, performing pre-classification of the anorthosite right in the sorter. This improved selectivity from the mining front to the crushing process, separating the anorthosite from the bauxite and during screening,” says Osmar Ribeiro, Beneficiation Supervisor at TGM.
RESULTS AND CONSOLIDATION OF THE PARTNERSHIP
After more than a year of operation, the partnership between TGM and STEINERT has been strengthened. STEINERT provides continuous support, with remote assistance and regular technical visits to optimize processes and make personalized adjustments in line with new market demands.
"We rely on the excellent support from the technicians at STEINERT Latinoamericana who are in constant contact with me and the operators, always ready to correct failures — something common in any process, regardless of the time," says Osmar Ribeiro, Beneficiation Supervisor at TGM.
During the assisted operation of the pilot plant, it was observed that the variation between the two predominant seasons in the region rainy and dry directly impacts the efficiency of separation due to changes in the material's characteristics. In response to this challenge, the STEINERT Global team actively worked to mitigate the production impacts and remains constantly attentive to provide support for the improvement of mineral operations.
As a result, the companies have established a solid partnership based on technical collaboration and continuous project development.
TGM's project coordinator, Everton Gonçalves, highlights: "The STEINERT KSS | XT CLI is a robust piece of equipment with impressive performance. It's a new experience at Terra Goyana, but the key words are performance and robustness."
DRY OPERATION AND COMMITMENT TO ESG: TOWARDS ZERO WASTE
TGM's process is 100% dry, using water only for infrastructure activities. This differentiator is fully aligned with the company's ESG practices, reinforcing its commitment to more sustainable mining.
With the implementation of the STEINERT Ore Sorter technology, TGM significantly increased the selectivity of the process, resulting in cleaner, higher-quality products that can be directed to new markets with more stringent requirements, without the need for wet beneficiation. Additionally, there was an increase in available reserves, as improving classification efficiency and ore recovery allows for better use of the deposit, thereby reducing future environmental impacts.
This technological evolution not only enhanced operational efficiency but also brought the company closer to one of its main goals: achieving zero waste production, consolidating a sustainable and profitable business model. This advancement is in complete harmony with STEINERT's philosophy, which generally promotes sustainability through innovative technological solutions. These technologies not only optimize processes and reduce waste but also reinforce the commitment to the circular economy, efficient resource use, and sustainable development, aligning with environmental preservation principles and the enhancement of industrial processes.
"We are always looking for new technologies, such as STEINERT's Sorter, to enable new products at TGM, ensuring not only financial returns but also environmental benefits. This approach is aligned with a safe operation, in compliance with environmental legislation and ESG principles," says Thalles Torres, Mine Planning Coordinator at TGM.
Today, the STEINERT Ore Sorter is a strategic pillar for TGM, providing not only efficiency and quality gains but also aligning with the internal project “Mine of the Future,” which represents the level of excellence the company seeks to achieve. This project incorporates features such as environmental responsibility, innovation, and maximization of mineral utilization.
The success at Barro Alto is a clear example of how technology, when properly applied, can transform challenges into solid and lasting results.