Relationship between solids density and the PFD80 transportable moisture limit of hematite-rich and goethite-rich iron ore fines
Relação entre densidade dos sólidos e o TML PFD80 de finos de minério de ferro hematíticos e goethíticos
Rodrigo Fina Ferreira; Rosa Malena Fernandes Lima
Abstract
The Transportable Moisture Limit (TML) is a relevant regulatory parameter for the mining industry, as it prevents the occurrence of mineral cargoes liquefaction aboard vessels, and represents a regulatory/technical restriction on shipments, requiring accurate moisture content control by the shipper. Determined through laboratory tests, the TML value varies with ore characteristics. This study investigated experimentally the influence of solids density on the TML of hematitic iron ore fines, using the Modified Proctor/Fagerberg Test for Iron Ore Fines, which defines TML as the moisture content at 80% saturation after compacting the test material applying a compaction energy of 27.59 kJ/m3 . The results showed that, for the same void ratio at 80% saturation, which is governed by a number of ore characteristics as particle size distribution, the lower the solids density, the higher the TML, which implies that ores with the same volumetric relationship between solids, water and voids, but with different mineralogical compositions, will have different TML values simply due to their different solids densities
Keywords
Resumo
O Limite de Umidade Transportável (TML) é um parâmetro regulatório relevante para a indústria de mineração, pois previne a ocorrência de liquefação de cargas minerais a bordo de navios, representando uma restrição regulatória/técnica para embarques, exigindo controle preciso da umidade pelo embarcador. Determinado por meio de ensaios laboratoriais, o valor do TML varia de acordo com as características do minério. Este estudo investigou experimentalmente a influência da densidade dos sólidos no TML de finos de minério de ferro hematíticos e goethíticos. O Ensaio de Proctor/Fagerberg Modificado para Finos de Minério de Ferro foi utilizado, o qual define o TML como a umidade correspondente a 80% de saturação após a compactação do material aplicando-se uma energia de compactação de 27,59 kJ/m3 . Os resultados mostraram que, para um mesmo índice de vazios em 80% de saturação, o qual é governado por diversas características do minério, como a distribuição granulométrica, quanto menor a densidade dos sólidos, maior o TML. Isso implica que minérios com a mesma relação volumétrica entre sólidos, água e vazios, mas com diferentes composições mineralógicas, terão valores de TML diferentes, simplesmente devido às diferentes densidades de sólidos.
Palavras-chave
Referências
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Submetido em:
10/03/2024
Aceito em:
31/08/2024
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