2579 MINERALOGICAL STUDY OF A BRAZILIAN LITHIUM-BEARING PEGMATITE *J.R. Figueiredo1,2,4, E.L. Reis1,2, G. Faria3, M.C. Vila4 1PPGEM, Federal University of Ouro Preto, Brazil (*Presenting author: janine.figueiredo@ufop.edu.br) 2Department of Mining Engineering, Federal University of Ouro Preto, Brazil 3Departament Metallurgical and Materials Engineering, Federal University of Ouro Preto, Brazil 4CERENA, Faculty of Engineering, University of Porto, Portugal ABSTRACT The world's growing demand for lithium and, consequently, the economic feasibility of mining and processing pegmatite projects, have led to investments in lithium exploration in Brazil. The recent discovery of new and significant reserves, as well as the expansion of already known mineralised areas, have put Brazil under consideration as a producer of lithium dioxide. Despite increased investment, it remains essential to expand research on lithium mineral processing routes and to refine existing processes. Moreover, the physical similarities between lithium minerals and gangue pose challenges for mineral separation. In this context, this work analysed lithium mineral processing projects in Brazil through feasibility studies conducted by mining companies and news coverage of recent lithium projects. Most of the projects analysed (in the pre-feasibility phase or in an operating mine) used dense medium separation to pre-concentrate lithium minerals. Based on these findings, characterisation of pegmatite samples from Minas Gerais was conducted, and sink-float tests were conducted to understand the applicability of dense medium separation in Brazilian pegmatites. The results indicate that lithium upgrading is density-dependent in the specific gravity interval of 2.70-2.89. Significant recovery and the study confirm the potential of dense media separation as a viable preconcentration route for lithium-bearing minerals. KEYWORDS Pegmatites, Spodumene, Critical Minerals, Dense Media Separation. 1. INTRODUCTION Lithium is found in three main types of deposits: 1) brines from evaporitic salars and geothermal deposits, located in Chile, Argentina, and Bolivia; 2) crystalline rocks enriched in lithium silicate and/or phosphate minerals, found in countries such as Australia, Brazil, Canada, Portugal, and Zimbabwe; 3) lithium-rich hectorite clays, derived from volcanic deposits, found in the United States and Mexico. Brazil has significant potential for lithium exploitation, as indicated by newly identified deposits totalling 1.3 Mt of Li2O in contained reserves (USGS, 2025), including spodumene, amblygonite, lepidolite, and petalite. Historically, lithium minerals in Brazil were mined and processed through artisanal methods, with manual sorting followed by dense media separation. In Brazil, spodumene-bearing pegmatites are mainly associated with minerals such as albite, petalite, quartz, microcline, muscovite, and feldspar. Important deposits occur in three main regions, known as Pegmatite Provinces: Northeast (Paraíba, Rio Grande do Norte, and Ceará), Eastern (Minas Gerais and Bahia), and Southern (São Paulo) (CPRM, 2020). There is also evidence of new prospective areas for lithium deposits in the states of Tocantins, Bahia, and Rio de Janeiro (DNPM,2016).
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