Papers by Ottavio Carmignano
Revista Brasileira de Inovação, May 7, 2023
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Journal of the Brazilian Chemical Society, 2021
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Journal of environmental chemical engineering, Aug 1, 2018
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Journal of the Brazilian Chemical Society, 2018
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International Journal of Minerals, Metallurgy and Materials, 2020
In this work, different magnesium silicate mineral samples based on antigorite, lizardite, chryso... more In this work, different magnesium silicate mineral samples based on antigorite, lizardite, chrysotile (which have the same general formula Mg3Si2O5(OH)4), and talc (Mg3Si4O10(OH)2) were reacted with KOH to prepare catalysts for biodiesel production. Simple impregnation with 20wt% K and treatment at 700-900°C led to a solid-state reaction to mainly form the K2MgSi04 phase in all samples. These results indicate that the K ion can diffuse into the different Mg silicate structures and textures, likely through intercalation in the interlayer space of the different mineral samples followed by dehydroxylation and K2MgSi04 formation. All the materials showed catalytic activity for the transesterification of soybean oil (1:6 of oil: methanol molar ratio, 5wt% of catalyst, 60°C). However, the best results were obtained for the antigorite and chrysotile precursors, which are discussed in terms of mineral structure and the more efficient formation of the active phase K2MgSi04.
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Journal of the Brazilian Chemical Society, 2020
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ABM Proceedings
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Material Science & Engineering International Journal
The serpentinite rock is formed by minerals of the serpentine group, such as antigorite and lizar... more The serpentinite rock is formed by minerals of the serpentine group, such as antigorite and lizardite, and can be found in several countries around the world. It has several commercial applications, among them its use as an ornamental rock. It can be found in numerous constructions, such as churches, houses and buildings. However, trade names are adopted for ornamental rocks, making it difficult to identify and confirm the existence of the specific rock in buildings. Using bibliographical research, the present work aims to study the use of serpentinite as an ornamental rock, identifying its first applications in the world and presenting commercial names adopted for this rock, allowing a better understanding of the relevance of this rock in world architecture. More than sixty commercial names of serpentinites used as ornamental rocks, in different applications, throughout different civilizations, were found.
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HOLOS
Rochas e minerais industriais são materiais aplicados na produção de uma grande variedade de prod... more Rochas e minerais industriais são materiais aplicados na produção de uma grande variedade de produtos, usados pela sociedade moderna. Um mesmo mineral ou rocha industrial pode ter diversas aplicações, dependendo de suas propriedades físicas, mineralógicas e químicas. O presente estudo teve como objetivo efetuar a caracterização tecnológica de uma amostra de metapiroxenito, proveniente da formação Córrego dos Boiadeiros, localizado no Quadrilátero Ferrífero, MG (Brasil), visando verificar possíveis aplicações industriais para o mesmo. Fluorescência de raios X foi utilizada para determinar os teores dos seguintes óxidos: 0,06% TiO2, 8,2% Fe2O3, 24,1% MgO, 2,1% Al2O3, 48,7% SiO2 e 1,8% CaO. Na caracterização mineralógica por difração de raios X, microscopia ótica, MEV/EDS e termogravimetria foram identificados os seguintes minerais: antigorita, clorita, cromita, ilmenita, magnetita, rutilo, talco e tremolita. Para os testes preliminares de concentração, o material usado (-147?m) apres...
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Scientific Reports, 2021
The iron mine tailings accumulation in dams is an environmental and economic problem. The composi... more The iron mine tailings accumulation in dams is an environmental and economic problem. The composite based on high-density polyethylene/iron mine tailing production for the application of wood plastic and some items of domestic plastic industry can be a good alternative to reduce the rejects in the environment. This work presents the influence of the processing methodology in the mechanical, thermal and morphological properties of composites based on the high-density polyethylene/iron mine tailing. Four methodology processing by continuous and/or batch mixing were available. The iron mine tailing particles in the polymer matrix promoted an increase in mechanical strength and thermal stability. Besides, the particles acted as flame retardant. The iron mine tailing materials produced using batch mixing showed more significant modifications in the properties due to the better dispersion of the filler as shown by scanning electron microscopy.
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Journal of the Brazilian Chemical Society, 2020
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Tecnologia em Metalurgia Materiais e Mineração, 2019
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Rem: Revista Escola de Minas, 2014
Pelletizing iron ore fines is an agglomeration process that through a thermal treatment converts ... more Pelletizing iron ore fines is an agglomeration process that through a thermal treatment converts the ultra-fines fraction thereof into small balls ranging in size from 8mm (0.31 in.) to 18mm (0.71 in.), with adequate characteristics for feeding steel reduction works. The binder more used to make pellets is bentonite, which is an item of significant cost in the process. The present paper aims at evaluating the use of serpentinite instead of bentonite. The results obtained show that the full substitution of bentonite for serpentinite is unfeasible. However a potential does exist for using serpentinite and bentonite together in the iron ore palletizing process in the proportion of 1:1.
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Papers by Ottavio Carmignano