EM - Escola de Minas
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6
Notícias
A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.
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Resultados da Pesquisa
Item Blending Linz–Donawitz and Blast Furnace slags with the Kambara reactor byproduct to improve their reuse in roadworks.(2022) Schumacher, Aécio Guilherme; Gomes, Guilherme José Cunha; Schneider, Denise S. G.; Pires, Patrício José Moreira; Gomes, Ruan Gonçalves de SouzaThe use of industrial byproducts as replacement of natural aggregates has been extensively investigated to design eco-friendly roads. One of the most examined byproducts for this purpose is steel slag. However, existing studies do not explore the blending of different slags to enhance the engineering performance of base layers. The applicability of Linz–Donawitz (LD), Blast Furnace (BF) and Kambara Reactor (KR) steel byproducts is evaluated as a single base layer for rural (unsurfaced) roads in Brazil. A series of laboratory experiments were performed to assess the characteristics of eight soil-byproduct mixtures with 50% and 75% byproduct contents, including new blends of LD/KR and BF/KR slags. Additionally, the most suitable mixture was proposed considering different performance indicators. Results demonstrate the coarse-grained, nonplastic and non-expansive nature of the byproducts, with CBR values higher than 100%. The more byproduct added to soil, the larger is the strength and the lower the expansion. The mixture with 75% of the proposed LD/KR blend and 25% of a clayey soil was considered as optimum, based on a trade-off between engineering properties, environmental impacts, and material costs. Findings and discussions are relevant to reduce waste stockpiles of steel companies, helping engineers and policy makers reuse blended slag byproducts.Item Ferronickel slag as free‐draining rockfll dike material : a novel waste solution for mining regions.(2022) Costa, João Paulo Rodrigues da; Gomes, Guilherme José Cunha; Fernandes, Gilberto; Magarinos, Dario Mozzer; Fonseca, Alberto de Freitas Castro; Pires, Patrício José MoreiraMining sites are vulnerable to erosion and siltation of rivers. While the construction of rockfill dikes can mitigate siltation, existing rockfill dikes are typically constructed with natural aggregates, whose mining, beneficiation, and transportation entail additional adverse impacts. In this paper, ferronickel slag (FNS) was investigated as a free-draining rockfill dike material to be used in nearby mining sites. A series of laboratory tests, including physical, environmental, durability, chemical and mineralogical analyzes, was executed to evaluate the engineering characteristics of this byproduct and its potential use in dikes. Results demonstrate that FNS is non-uniform with relatively low Los Angeles abrasion. Leaching and dissolution tests have not shown harm to the environment since the average concentrations of chemical elements existing in FNS were below the standard requirements. Accelerated weathering cycling tests with ethylene glycol further highlighted that the byproduct does not suffer premature disaggregation in the presence of water, thereby revealing that the material can be employed adequately under saturated condition. Findings suggest that the use of FNS in rockfill dikes represents a technically and environmentally feasible solution, while reducing the use of natural aggregates, avoiding the formation of stockpiles, preventing siltation in downstream fluvial networks and other adverse impacts.Item Toward improved performance of unpaved roads : laboratory tests and field investigation of a soil-byproduct base layer.(2020) Magalhães, Adair José de; Gomes, Guilherme José Cunha; Pires, Patrício José MoreiraIn this study, the performance of two steel slag byproducts is investigated to produce mixtures for base layers of unpaved roads. The basic physical properties including Atterberg limits, grain size distribution, California bear- ing ratio and expansion tests of eight different mixtures of soil-byproduct are investigated in laboratory to understand the engineering properties of the mixtures. The byproducts are mixed in different proportions from 50% to 80% by weight with a local (clayey) subgrade soil. Subsequently, two selected mixtures are used to build an experimental road section along an unsurfaced road. Results demonstrate that the gradation and strength of the samples satisfy the requirements for base layers. Furthermore, the mix- tures are shown to be of low-plasticity at higher byproduct content and non-expansive. Field investigations show that 12 roller passes at the stan- dard Proctor and 14 at the intermediate Proctor are enough to reach 100% of the degree of compaction.