PRE-CONCENTRATION AND ORE SORTING
Tr ransforming bauxit
e beneficiation
Terra Goyana Mining( TGM) benchmarks itself in mineral resear
ch, development, beneficiation and bauxite commercialisation, with its ore sor ting strategy helping affirm these aims, STEINERT says.
TGM has operations at the Barro Alto mine( Goiás) and an office in Goiânia, and is part of the Supergram group, which operates in various sectors, including commercial bauxite extraction.
TGM is looking to transform compact bauxite into a material with accepted calcium and aluminium content, to meet increasingly stringent market standards. This has led it to implement sensor-based sorting( SBS) technology
.
Previously, material classification at Barro Alto was carried out through screening alone, 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 CaO to below 0.15 %. Additionally
, increasing the aluminium oxide( Al�O�) content range between 62 % and 63 % was deemed 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.
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It was in this context that the partnership with STEINERT Latinoamericana was established, providing SBS technology.
José Maurício, TGM’ s Planning Manager, said:“ The application of an 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.” 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 STEINERT KSS | XT CLI equipment equipped with XRT, colour, 3D laser and magnetic induction sensors were used to enable precise material analysis.
In the first round of tests, using two 2 t samples, the results showcased a customised configuration for each material type, with a combination of XRT and 3D laser sensors ensuring highly efficient separation, according to STEINERT.
This initial success led to a second round of testing, focused on an even greater challenge: obtaining premium bauxite with high Al�O� content while reducing contaminants such as silicon dioxide( SiO�), hematite( Fe�O�), CaO and magnesium oxide( MgO), in a finer size fraction.
After finetuning the process, STEINERT’ s technology demonstrated its full capability to: Reject particles with high iron content; Significantly increase Al�O� levels; and Reduce impurities to meet market standards. The second test confirmed the efficiency of XRT technology in removing contaminants, achieving the desired parameters( CaO < 0.1 %)
and reducing Fe�O� contamination in the reject material, which showed
“ T GM’ s str ategy for directing ore sorter products reinfor ces the zero- waste concept, enabling the production of high-value bauxite and the commercialisation of reject material for v
arious industries, such as cement, ceramics and metallurgy,” STEINERT says
levels between 7 % and 22 %.
STEINERT says:“ TGM’ s strategy for directing ore sorter products reinforces the zero-waste concept, enabling the production of high-value bauxite and the commercialisation of reject material for various industries, such as cement, ceramics and metallurgy. This expands both sustainability and the economic feasibility of the process.”
Alexandre Rosa, TGM’ s PCP Supervisor, said:“ 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 optimise operational profitability and enhance the product.”
One of the improvements proposed by the STEINERT Latinoamericana team during the initial phase of the pilot plant was the use of object formation optimisation technology on its software to improve particle recognition and ejection accuracy
.
This helped counteract the effects of fines in the feed material while meeting the requirement to adjust the processed material’ s particle size. As a result, data accuracy increased, result variability decreased and plant productivity improved significantly
,
according to the company
. Following this test work, TGM acquired its first STEINERT sorting system, with Osmar
Ribeiro, Beneficiation Supervisor at TGM, excited by the results:“ 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.”
After more than a year of operation, the partnership between TGM and STEINERT has been strengthened, the company says. STEINERT provides continuous support, with remote assistance and regular technical visits to optimise processes and make personalised adjustments in line with new market demands.
During the assisted operation of the pilot plant, it was observed that the variation between the two predominant seasons – 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. 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, STEINERT says.
Mine to Mill Powered by ShovelSense – ShovelSense and BeltSense units combined – installations would occur this year, providing the
evidence that the initial‘ diversions in the pit’ value case MineSense defined early on is now being expanded to data in the plant.
“ We’ re still big believers that actual sorting should be done at the face,” he said.“ Our BeltSense installations aren’ t focused on
72 International Mining | APRIL 2025