Optimização do estágio primário de modo a reduzir o teor de contaminantes do produto IP2 no circuito de ilmenite na planta de separação mineral da Kenmare

Abstract

Mozambique is recognised for its wealth of heavy minerals such as ilmenite, rutile, and zircon, whose exploitation, particularly the Moma Project operated by Kenmare Resources, drives the national economy, generates employment, and attracts foreign investment. In the context of mineral beneficiation, processes such as magnetic separation and electrostatic separation are fundamental for obtaining products with a high degree of purity. The present study, developed as part of a professional internship at Kenmare, aimed to optimise the primary stage of the Ilmenite A circuit to reduce the content of critical contaminants (P₂O₅ and U+Th) in the IP2 product, ensuring compliance with commercial and regulatory specifications. The experimental approach consisted of tests on the Mag 1 stream, varying operational parameters such as discharge splitter position and magnetic drum speed, followed by chemical analyses using XRF and magnetic fractionation tests. The results showed that the intermediate splitter position (2 mag), associated with 100% drum speed, presented higher efficiency in rejecting contaminants without significantly compromising yield, while excessively low speeds increased the retention of unwanted particles. It was evidenced that the optimised operational configuration is more effective than isolated speed adjustments. As observed in other studies conducted at Kenmare, precise adjustments of magnetic separation parameters are crucial for maximising purity and recovery. In the specific case of IP2, the final recommendation is to adopt the 2 mag splitter configuration and maintain 100% operating speed, in order to ensure stable quality and competitiveness in the international market.