With more than 35 years of experience, the company operates vertically from spodumene mining in Araçuaí, located in the Jequitinhonha Valley (MG), recently recognized as Brazil’s Lithium Valley, to the chemical conversion of the concentrate at its industrial plant in Divisa Alegre (MG).
CBL supplies both domestic and international markets with high-purity lithium products for battery, ceramic, glass, pharmaceutical, and lubricant industries. Committed to innovation and sustainability, the company continuously invests in technology and process improvement, positioning itself among the leading lithium players in Latin America.With the growth of mining activities in the Jequitinhonha Valley, the region has established itself as a hub for the exploration of spodumene-bearing pegmatites, attracting new projects year after year. CBL, however, has been operating in the region for over three decades, being the pioneer in spodumene extraction and processing in Brazil and, currently, the only company converting concentrate into lithium carbonate and hydroxide within the country. The company is committed to innovation and sustainability, constantly investing in technology and process improvement to remain a leading lithium producer in Latin America.
Challenge: Reducing Dilution to Optimize Spodumene Concentration Performance
Since the beginning of operations, one of CBL’s main challenges has been ore dilution caused by the presence of schist, the host rock of the pegmatite bodies. This dilution directly impacts the quality of the final concentrate and lowers the efficiency of downstream processing stages. As competition in the lithium market intensifies and operational efficiency becomes a decisive factor, finding solutions capable of improving selectivity, upgrading product quality, and reducing costs has become essential.
Traditionally, the beneficiation of lithium-bearing pegmatite ores can follow different routes, with flotation and Dense Media Separation (DMS) being the most common. Flotation is mainly used for fine-grained deposits, exploiting differences in surface properties between minerals through reagents and pulp aeration. DMS, in contrast, is preferred for coarser-grained ores such as those in the Araçuaí region, relying on density differences to achieve separation. Although DMS is effective, its performance is challenged by the fact that schist has a specific gravity very close to that of spodumene, which compromises separation selectivity. Under these conditions, concentrates typically reach around 5.7% Li₂O, still containing significant diluting materials that limit plant efficiency. In the Lithium Valley, both open-pit and underground mining operations face this persistent dilution challenge. The standard beneficiation routes, involving crushing, screening, and DMS, are able to produce a spodumene concentrate but cannot fully address the issue when schist is present in high proportions. This constraint not only affects concentrate grade but also increases the volume of material processed in later stages, with direct implications for energy, water consumption, and overall operating costs.
Sensor-Based Sorting for Early Removal of Schist Before DMS
To address the persistent dilution challenge, CBL implemented Sensor-Based Sorting, also known as Ore Sorting, as a strategic pre-concentration stage positioned immediately after primary crushing. This stage targets the -100 +19 mm particle size fraction, which represents approximately 70% of the Run-of-Mine (ROM). The goal is to remove schist early, typically 5 to 20% of ROM, before the Dense Media Separation (DMS) stage, improving feed quality and process selectivity.
The industrial installation operates at a nominal capacity of 100 t/h and is fully dry, eliminating water usage and the need for tailings dams. The sorting system identifies and separates material based on intrinsic physical properties such as atomic density, surface colour, and particle shape and brightness, enabling real-time, high-precision removal of schist from spodumene-bearing ore.
The selected unit, STEINERT KSS | CLI XT, features a primary X-ray Transmission (XRT) sensor supported by high-resolution colour cameras and 3D laser scanners. This multisensor configuration simultaneously detects density contrasts, surface textures, and three-dimensional particle geometry, achieving precise lithological discrimination even when density differences are minimal. A major advantage of the multisensor approach is operational flexibility. The system can combine multiple separation criteria and adjust ejection logic to accommodate lithological variability and changing ore characteristics over time. It can also operate efficiently across a wider particle size range, adapting to ROM variations and production changes. This versatility and easiness of integration into the existing plant were decisive factors in technology selection, especially as CBL plans to expand production capacity at both the mine and chemical plant with minimal additional investment. Adailton Almeida, CBL’s Beneficiation Coordinator says: “By removing schist after the primary crushing stage, we gained flexibility in the DMS feed separation due to the density of other minerals, since schist has a density very close to the spodumene.”
Dry operation and ESG Commitment: Reduction of Environmental Impact and Conscious Natural Resources Use
Since commissioning, the SBS installation has delivered outstanding improvements to CBL’s spodumene beneficiation circuit. Lithium metallurgical recovery consistently surpasses 90%, while the reject stream averages only ~0.3% Li₂O, highlighting the exceptional precision and selectivity of the process. Removing over 95% of schist before the DMS stage ensures a cleaner, higher-grade feed, boosting DMS efficiency, stabilizing plant performance, and maximizing overall lithium recovery. By upgrading the concentrate and enhancing process selectivity, the Ore Sorter enables more efficient use of the orebody, expanding economically viable reserves and reducing waste rock volumes. It is an approach that not only generates technical and economic value but also mitigates regulatory and social risks associated with the intensive use of natural resources.
According to Priscila Esteves, PhD, Head of the Technical Department at STEINERT: “The CBL deposit is characterized by a pegmatite with large crystals, which allows some minerals to be liberated right after primary crushing. This enabled pre-concentration at this stage, reducing the volume processed in downstream stages and leading to lower operational costs and reduced generation of fine tailings. There is also a positive effect on the quality of the product fed into the DMS.” CBL’s experience demonstrates that advanced technologies such as Sensor-Based Sorting can transform operational strategies. Beyond a beneficiation tool, SBS has become a strategic pillar—driving higher productivity, reinforcing environmental stewardship, and ensuring the long-term sustainability and resilience of the operation.
Results, technical support and future vision
Following its implementation on an industrial scale, the results achieved through the application of Sensor-Based Sorting technology at the CBL plant have consolidated its role as a fundamental part of the beneficiation circuit. The partnership with STEINERT Latinoamericana goes beyond the supply of equipment, including ongoing technical support, remote monitoring, periodic visits, operational adjustments tailored to the process demands, mine and seasonal variations in operation. This model of continuous technical collaboration is one of the pillars of the project's evolution and supports CBL’s ambition to increasingly incorporate process intelligence into its operations. The application of sensor technology, combined with robust and responsive operations, has delivered significant gains in selectivity, productivity, and sustainability, all of which are essential parameters for the company’s competitive positioning in today’s global lithium supply chain.
More than a circuit upgrade, the introduction of the Ore Sorter reinforces CBL’s commitment to sustainable mining, a model of operation that combines environmental responsibility, maximized mineral recovery, and the adoption of cutting-edge technologies. The partnership with STEINERT remains a solid foundation for ongoing development, with expectations of further advances in automation, real-time monitoring, and process control, expanding the positive impact of this application and enabling increasingly cleaner, safer, and more efficient mining.
With its industrial-scale implementation, SBS has become a cornerstone of CBL’s beneficiation circuit. The technology has delivered efficiency, but the true differentiator lies in the way the partnership with STEINERT Latinoamericana was built: side by side, combining technical expertise, innovation, and support. More than equipment supply, this collaboration includes daily technical assistance, remote monitoring, regular on-site visits, and operational adjustments tailored not only to process demands but also to natural challenges such as geological variability and seasonal changes. The results are already clear: significant gains in selectivity, productivity, and sustainability, key factors for keeping CBL competitive in the global lithium market. In addition, the fully dry operation underscores the company’s commitment to responsible environmental practices. The partnership between STEINERT and CBL not only modernizes lithium beneficiation in Brazil but also sets a new benchmark for collaboration in the sector, driven by innovation and sustainability.