Navegando por Assunto "Rejeito de manganês"

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Acesso aberto (Open Access)
Avaliação tecnológica de cerâmicas tradicionais incorporadas com rejeito do minério de manganês
(2014-12) RODRIGUES, L. dos S.; SILVA, J. C.; ANGÉLICA, Rômulo Simões; RABELO, A. A.; FAGURY, Renata Lilian Ribeiro Portugal; FAGURY NETO, Elias
The ceramic industry has a great environmental role when it comes to recycling waste. The industrial production that has been developed in the Northern Region of Brazil makes room for use of waste as a substitute raw material in the production of ceramics. This substitution in addition to the environmental advantage also provides interesting physical characteristics in the ceramics produced. This work aimed to study the effects caused by the incorporation of manganese ore tailings in formulations of ceramic clay, to examine the extent to which it is possible to incorporate this waste without prejudice to the product properties. It was proposed some formulations containing varying amounts of tailings. The ceramic bodies were shaped and sintered at 1000 ºC to 1200ºC for 2 h. Results demonstrated that the material showed a decreasing in the porosity and water absorption, and an increasing in the bending strength as a result of the densification promoted by the tailing incorporation which acts as fluxing agent.
Acesso aberto (Open Access)
Rejeito de manganês, proveniente da Amazônia Oriental, em substituição parcial do agregado miúdo natural em concreto
(Universidade Federal do Pará, 2019-03-21) SILVA JÚNIOR, Paulo Rogério; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
Research on partial or total substitution of the natural fine aggregate for ore tailings has gained strength in recent years. Most part of these tailings are destined to dams, which are subject of ruptures resulting in social, economic and environmental loses. The most recent example is the rupture of Brumadinho-MG dam in january, 2019. Despite of all the risks associated to the mining activity, the extraction of ore tends to increase due to the final products generated by this activity such as steel, batteries and electronics. Natural sand is mostly obtained by dredging activity, which involves the deforestation of certain areas and the possible contamination of the water with diesel oil from dredgers. This research aims to study the partial replacement of natural sand by manganese tailing (in 15%, 20%, 25% and 30% proportions) from the eastern Amazonia, Marabá-PA municipality, for the construction of structural concrete without the use of superplasticizer. Analyzed the results for the test of workability, mechanical strength, water absorption and microstructure for the samples of concrete with and without tailings. It has been found that manganese tailing is a thin material that has a high specific surface, which demands high demand for water when compared to the reference concrete. It was verified that there was a decrease in the mechanical properties of the refuse concrete due to the added water, however, the water absorption was equal to the reference one.
Acesso aberto (Open Access)
Rejeito do minério de manganês como material de construção civil
(Universidade Federal do Pará, 2017-06-02) VIVEIROS, Danielle de Cássia Santos de; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
The increasing global demand for manganese ore and environmental impacts associated with the disposal of ore waste have motivated studies about the reuse of materials from tailings dams. In this context, the main objective of this work was to study the reuse of manganese waste as materials for civil construction. For this purpose a characterization of the Mn tailings was made from a physical, chemical, mineralogical, environmental and reactivity point of view. From these analyzes, feasible applications for the tailings were investigated. The first one was to study its reutilization as a filler in Portland cement. For this, reference mortars and mortars with 6, 8 and 10% substitutions were made to the cement. The mortars were tested for compressive strength and total water absorption and voids index at 28 days. The tests showed that the mortars with substitution contents obtained positive results when compared to the reference mortars. Inducing the resistance gain mainly for the percentages of 6 and 8%, as well as for the results of total absorption and voids index. A second investigation was carried out to study the reuse of Mn tailings as a fine aggregate in the manufacture of concrete. For this purpose, reference concrete and concretes were made with 15, 20, 25 and 30% substitutions to the natural fine aggregate. Through the analysis of resistance to axial compression a positive result was observed for both samples, especially for concretes with 15 and 20% substitution. The tests of tensile strength and modulus of elasticity achieved satisfactory results for both samples, especially for concretes with 20, 25 and 30% of substitution. In the capillary absorption analysis, the concretes with substitutions presented significant variations when compared to the reference concretes. The samples of 15% and 30% were the ones that less absorbed water, and the results of the 20 and 25% samples were still below the absorption values of the reference concrete. In this way, the reuse of this waste as materials for civil construction becomes feasible from a technical and environmental point of view.
Acesso aberto (Open Access)
Tilojo solo cimento com adição de rejeito de manganês do sudeste paraense
(Universidade Federal do Pará, 2015-04-24) NASCIMENTO, Antonio Carlos Santos do; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
The housing issue, with regard to constructive inputs used, it is urgent for a paradigm shift that provides the adequacy of the project, many local specificities, as well as playing practice in man in its territory. Considering the Amazon that, like other areas of the country goes through an intense densification of cities, it is still the scene of action, not always positive, large mining projects, which in its wake, bring the issue of disposal of the waste to add the local issues. This work proposes as a solution path for the problem of mineral waste and constructive input: the soil-cement with the addition of mineral waste brick, reject it originates from the southeast of Pará manganese exploration Because the soil with cement brick. waste mineral manganese meet the requirements set by the NBR 8491/2012, presented compressive values above individually to 1.75 MPa, water absorption values lower than 20%, and negligible dimensional change, it still demonstrates its suitability major weather of the region - ultraviolet radiation and humidity - due to the results obtained in the accelerated aging test chamber. The results show promise, and beyond to suit the rules do not interfere significantly in the production process already developed, has large membership possibilities, contributing to building a new paradigm of development.