Navegando por Autor "Cunha, Anderson Alves"

Agora exibindo 1 - 4 de 4

Caracterização tecnológica e estudo termomagnético de rejeitos de minério de ferro.
(2015) Cunha, Anderson Alves; Araujo, Fernando Gabriel da Silva
Diante do cenário macroeconômico internacional, o setor mineral busca soluções inovadoras e sustentáveis para seus processos produtivos. Uma dessas soluções é, sem dúvida, aumentar a recuperação do mineral de interesse presente no rejeito, proveniente de operações de beneficiamento de baixa recuperação metalúrgica. Outro princípio é a aplicação de técnicas para a produção mais limpa, na qual se identificam as fases do processo em que os resíduos são gerados e qual a tecnologia necessária para seu reaproveitamento, seja no próprio sistema produtivo ou em um sistema produtivo diverso, estabelecendo-se o conceito de sustentabilidade na mineração com resíduo zero. Contudo, para direcionar esse material para uma determinada tecnologia é fundamental conhecer suas características e propriedades específicas. O presente trabalho busca extrair informações significativas a respeito das diversas faixas de tamanhos de partículas existentes no rejeito de flotação e da deslamagem do beneficiamento de minério de ferro. As amostras utilizadas foram provenientes de uma mineradora do Quadrilátero Ferrífero, Minas Gerais. Para isso, foram utilizadas técnicas de caracterização tecnológica, como classificação granulométrica (peneiramento a úmido e cyclosizer), fluorescência de raios X, difração de raios X, microscopia óptica, microscopia eletrônica de varredura com microssonda EDS acoplada, picnômetro de hélio e ensaios termomagnéticos por meio de susceptibilímetro magnético. Os resultados mostram que as distribuições granulométricas das amostras variam de 100μm até valores menores que 4μm, com presença significativa de óxidos de ferro e quartzo, além de pequenas quantidades de contaminantes, como alumina e fósforo. Os minerais de ferro identificados foram hematita, martita, goethita e magnetita e os de ganga foram quartzo e caulinita. As curvas termomagnéticas geradas permitiram identificar o efeito de Hopkinson, juntamente com as temperaturas de Curie da magnetita e hematita, e indicam também que o potencial magnético de cada faixa granulométrica está diretamente relacionado com o volume de magnetita presente.
The formation of Brazilian minerals database for integrated SEM-EDS system applied to the gold ore characterization.
(2018) Sampaio, Ney Pinheiro; Castro, G. G.; Moreira, Gilson Frade; Silva, Fabiane Leocádia da; Mendes, Jefferson Januário; Cunha, Anderson Alves; Krüger, Fernando Leopoldo von; Araújo, Fernando Gabriel da Silva
The mineralogical characterization of the Brazilian minerals variety occurrence is one of the key steps in the design of the mineral processing route and improving the overall process efficiency. This set of information is essential in assessing the technical and economic viability of a mineral Project. Among the variety mineralogical characterization techniques, automated analyzers are gaining great prominence because they provide qualitative and quantitative data in an automated manner, with great speed and accuracy. The system, available in the NanoLab at the Laboratory of the Mining-Metallurgic Centre/REDEMAT and specifically called TIMA-MIRA, is composed of a scan control program and analysis of mineral data (TIMA - Tescan Integrated Mineral Analyzer) and a scanning electron microscope with cannon field emission of electrons associated with two energy dispersive detector characteristic X-rays (MIRA - trade name). The system uses a mineral database consisting of association images by back scattered electrons of the mineral grains, with their characteristic X-ray spectra and their comparison with the characteristic spectra of a database. The equipment has an interface that allows you to add minerals and other materials to their underlying database, which is critical to the result accuracy because the original equipment database that is created only with data of mineral samples from other countries would not identify minerals of national origin with its characteristic major and minor elements. These limitations of the database integrated mineral analyzer TIMA-MIRA motivated the construction of a new database through a selection methodology, preparation and analysis by diffraction rays and the TIMA-MIRA system, different context samples Brazilian geological. Each mineral was determined to be analyzed in the integrated mineral analysis system by the XR diffraction analysis. Thereby, we obtained the maximum and minimum intensities values of chemical elements peaks that make up the analyzed mineral obtaining thus new identification rules for each selected species and adapted some existing rules to meet the needs presente.
Thermomagnetic study for identification of mineral phases.
(2017) Cunha, Anderson Alves; Silva, Fabiane Leocádia da; Silva, Blênio Márcio Cunha; Mendes, Jefferson Januário; Solé, Rubén Antonio Llobell; Araújo, Fernando Gabriel da Silva
The characterization of materials is an area of extreme importance for engineering, it uses a range of instrumental techniques to provide an information bank for material analysis and selection. In the treatment of iron ore the mineralogical characterization is done, almost exclusively, by optical microscopy. However, materials with very fine granulometry, below 4 μm, make their preparation and visualization restricted in this equipment. The present work aims to identify the minerals Hematite, Magnetite and Goethite in samples of tailings from the iron ore processing, employing a Bartington MS3 that evaluates the magnetic susceptibility as a function of the temperature. These measurements make it possible to identify Curie temperatures characteristic of Magnetite (580 °C) and Hematite (675 °C), as well as Goethite’s Neel temperature (120 °C). The results showed that the application of the technique is of great value for the identification of the magnetic bearing minerals and the quantification of the magnetic potential of the sample.
Thermomagnetic study of iron ore tailings from Quadrilátero Ferrífero - Minas Gerais/Brasil.
(2018) Mendes, Jefferson Januário; Cunha, Anderson Alves; Ávila, Kelly de Souza Pires; Solé, Rubén Antonio Llobell; Araújo, Fernando Gabriel da Silva
Within the international macro-economic scenario, the mineral sector is seeking innovative and sustainable solutions for their productive processes. However, to be able to direct the tailings toward a determined technology, it is fundamental to know its characteristics and specific properties. The objective of the study presented herein was to extract significant information regarding the various ranges of particle size existing within the tailings from iron ore processing, with special attention to its magnetic properties. For this were used different technical characterization. The results demonstrate that the granulometric distributions of the samples vary from 100μm to values of less than 4μm, with a significant presence of iron oxides and quartz. The thermomagnetic curves generated permitted identification of the Hopkinson Effect, Curie temperatures for magnetite and hematite. They also show the magnetic susceptibility of each grain size range, an important information when considering magnetic separation.