DEMIN - Departamento de Engenharia de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/510
Navegar
6 resultados
Resultados da Pesquisa
Item Concentration of oxidized Brazilian zinc ore by flotation : comparative study between anionic and cationic routes.(2022) Ferreira, Pedro Henrique Tófani; Lima, Rosa Malena FernandesIn this work, a mineralogical characterization by X-ray diffractometry and thermogravimetric analysis of a new Brazilian zinc ore sample was performed. The mineralogical semi-quantification, conducted by normative calculation of the identified minerals, using their theoretical chemical formulas and the contents determined in the chemical analyses was as follows: smithsonite (20.3%), goethite (49.6%), kaolinite (12%), quartz (6.2%), cerussite (3.0%), chlorite (4.0%), dolomite (0.5%) and others (4.4%). Subsequently, bench flotation tests were executed, using sodium oleate (anionic route) and amine (cationic route) as smithsonite collectors. Sodium silicate was used as a depressant of the gangue minerals in both routes tested. These studies showed that the anionic route (30.1% Zn in concentrate and 83% Zn recovery) performed better than the cationic route (17.5% Zn in concentrate and 46.3% Zn recovery). Considering the mineralogical composition of the concentrates obtained in the best flotation results, associated with physicochemical studies published in the literature with the identified minerals, it was evidenced that the difference in performance between the tested routes is due to the influence of ions from the dissolution of carbonates present in the ore on the surface properties of the main gangue minerals (goethite and silicates), especially for the cationic route.Item Relationship between particle size distribution and the PFD80 transportable moisture limit of iron ore fines.(2022) Ferreira, Rodrigo Fina; Lima, Rosa Malena FernandesSince 2011, mineral cargoes shippers shall comply with a regulatory framework established by the United Nation’s International Maritime Organization (IMO): the International Maritime Solid Bulk Cargoes (IMSBC) Code. Some wet mineral cargoes, including some types of iron ore fines, may liquefy during ocean transport, i.e., the cargo can shift and lead the vessel to sink. According to the IMSBC Code, for safe shipping, the moisture content of these cargoes shall be lower than a regulatory limit: the Transportable Moisture Limit (TML). Iron ore fines TML can be obtained through the Modified Proctor/Fagerberg Test for Iron Ore Fines (PFD80), a dynamic compaction test which consists in compacting ore samples at different moisture contents, the TML being the moisture content at which the material reaches 80% saturation. TML has become a relevant parameter for the mining industry, firstly due to the crew and ship safety aspect, and because failure to comply with the TML can legally interrupt an ore shipment or even an entire mining/shipping operation. Therefore, knowledge related to the TML and the understanding of how it varies with ore characteristics are essential. Despite that, research works on this topic are still scarce. In this study, the relationship between particle size distribution and the TML of iron ore fines was experimentally investigated. The results have shown that the TML is highly related to the particle size distribution of the tested material, and that the TML variations can be explained by structural packing effects caused by particle interactions during compaction for different types of size distribution. It was also found that the coefficient of uniformity can be used for numerically representing the particle size distribution in order to establish relationships with the TML. Another relevant conclusion is that the TML of a mixture of different iron ore fines may not be the result of the weighted average of the individual components’ TML. This knowledge is of utmost importance for the industry, as blends of different ore products are common practice, and this finding is relevant for other cargoes that are susceptible to liquefaction.Item Reverse cationic flotation of iron ore by amide-amine : bench studies.(2022) Rocha, Geriane Macedo; Cruz, Marcus Vinicius Macedo da; Lima, Neymayer Pereira; Lima, Rosa Malena FernandesThis study evaluated the performance of a new collector amide-amine compared with a traditional etheramine in conventional reverse cationic flotation of a siliceous itabirite sample of the Quadrilatero Ferrı ́fero (d80 1⁄4 116 mm, 40% Fe and 41.2% SiO2). Statistical design of experiments was used to determine the influence of pH, collector and starch dosages on mass and Fe recoveries, Fe and SiO2 grade in the concentrate, Fe grade in the tailings and Gaudin's selectivity index (S.I). For the amide-amine, starch had no significant effect on mass recovery and in the Fe and SiO2 grade in the concentrate. For the same dosages, it was found that amide-amine was less selective than etheramine. However, at higher dosages, at pH 8 and without starch, concentrates with Fe >65% and SiO2 <5% grades were obtained, similar to the grades obtained with etheramine and starch at pH 10.5. The mass and Fe recoveries were higher and consequently, the Fe grades in the tailings were lower. These results indicate that, despite the higher dosage required, amide- amine is selective without starch, which is very interesting from the economic point of view and simplification of the process route, implying a great potential for its industrial application.Item Technological characterization of metapyroxenite of the Córrego dos Boiadeiros Formation, Nova Lima (MG), Brazil.(2021) Ferreira, Bruno Trindade; Santos, Maristella Moreira; Lima, Rosa Malena Fernandes; Brito, Hermando; Carmignano, Ottavio Raul Domenico RibertiRocks and industrial minerals are raw materials employed in the production of a wide variety of products, used by modern society. The same mineral or industrial rock can have several applications, depending on their physical, mineralogical and chemical characteristics. The present study had as its objective, the technological characterization of a metapyroxenite sample, belonging to the Córrego dos Boiadeiros body in the Quadrilátero Ferrífero, MG (Brazil) in order to verify its possible industrial applications. For this research study, X-ray fluorescence chemical analyzes were performed, which determined the following oxides: 0.06% TiO2, 8.2% Fe2O3, 24.1% MgO, 2.1% Al2O3, 48.7% SiO2 and 1.8% CaO. In the mineralogical characterization by X-ray diffraction, optical microscopy, SEM / EDS and thermogravimetry, the following minerals were identified: antigorite, chlorite, chromite, ilmenite, magnetite, rutile, talc and tremolite. For the preliminary concentration tests, the material used (-147μm) presented 32% of the particles in the fraction -37μm with d50 in 74μm. The 3575 Gauss magnetic field and the particle size fraction -74μm generated a mass recovery of 96.4% and a whiteness of 61.9% for the non-magnetic product. Although no talc enriched products were generated by preliminary magnetic separation tests, the non-magnetic products presented specifications for the following applications: paper (wallpaper and packing), insecticide and fertilizers.Item Efeito dos íons Ca2+ E Mg2+ na flotação catiônica reversa de minério de ferro itabirítico.(2021) Cruz, Daniel Geraldo da; Gonçalves, Paola Suzane Moreira; Lelis, Deisiane Ferreira; Lima, Rosa Malena FernandesNeste trabalho foi avaliado o efeito dos íons Ca2+ e Mg2+ , adicionados como sais de cloreto, na flotação catiônica reversa em pH 10,5 de uma amostra de minério de ferro itabirítico. Em geral, foi observado que concentrações totais de íons maiores que 83 mg/L em solução aquosa aumentou a recuperação de Fe e teor de SiO2 nos concentrado obtidos comparado com os ensaios efetuados na ausência dos mesmos. Ocorreu o oposto com o teor de Fe. Este efeito é devido à atração eletrostática entre as espécies positivas provenientes da hidrólise destes íons em solução aquosa e a superfície negativa do quartzo, que evitou a adsorção dos íons amonium, cujo principal mecanismo de adsorção é por atração eletrostática dos mesmos com a superfície mineral negativa. Contudo, o uso de ácido etilenodiiaminotetracético - EDTA após o condicionamento do minério com os íons Ca2+ e Mg2+, em proporções adequadas de EDTA para íons totais, produziu concentrados com teores de Fe e SiO2 similares aos concentrados desta amostra na ausência de íons, uma vez que eles foram complexados pelo EDTA e não foram mais adsorvidos na superfície negativa do quartzo.Item Quartz and hematite activation by Zn, Ca and Mg ions in the cationic flotation route for oxidized zinc ore.(2021) Duarte, Geraldo Magela Pereira; Lima, Rosa Malena FernandesAnionic, cationic and cationic/anionic flotation is widely used in the concentration process for low-grade oxidized zinc ores. In the cationic flotation route, sodium silicate is used as a depressant for gangue minerals and amine as a collector for zinc minerals previously activated by sodium sulfide. However, the presence of polyvalent ions in aqueous solution can affect the surface properties of the various minerals and consequently, the selectivity of the process. This study evaluated the effect of Zn, Ca, and Mg ions, originated by the solubility of smithsonite and dolomite, on the surface properties of quartz and hematite. Microflotation tests showed the inefficiency of sodium silicate as a depressant for quartz in aqueous solution even when Zn, Ca, and Mg ions were not present. Activation of hematite by Zn ions was observed, impeding the separation of smithsonite and hematite (iron oxide). Results obtained from the microflotation and zeta potential tests were analyzed based on the speciation diagrams of the reagents and ions studied, as well as published studies.