24 documents found, page 1 of 3
Iron Recovery from Iron Ore Tailings by Direct Hydrogen Reduction at Low Temper...
Pinto,Paula S.; Milagre,Luisa E.; Moreira,Larissa C. M.; Rocha Junior,Hamilton P.; Salviano,Adriana B.; Ardisson,José D.; Parreira,Fabrício V.In this work, we describe a sustainable alternative to recover iron from two iron ore tailings (IOT) using hydrogen reduction at relatively low temperatures followed by magnetic separation. X-ray powder diffraction (XRD), inductively coupled plasma (ICP), atomic absorption (AA), Mössbauer, scanning electron microscopy (SEM/EDS), Raman and thermogravimetry (TG) analyses indicated that the Fe oxide present in the...
Movimento Química pós 2022: construção de um plano de ação para que a Química e...
Silva,Ingrid F.; Nascimento,Pedro H.P.; Lago,Rochel M.; Ramos,Mozart N.; Galembeck,Fernando; Rocha Filho,Romeu C.; Teixeira,Ana Paula C.Considering the bicentenary of Brazil’s Independence in 2022 and that this year was proclaimed by UNESCO as the International Year of Basic Sciences for Sustainable Development, in mid-2021 the Brazilian Chemical Society (SBQ) launched the “Post 2022 Chemistry Movement - Sustainability and Sovereignty”, with the main goal of promoting different activities so that chemistry contributes for the sustainable develo...
Iron Ore Tailings: Characterization and Applications
Carmignano,Ottávio R.; Vieira,Sara S.; Teixeira,Ana Paula C.; Lameiras,Fernando S.; Brandão,Paulo Roberto G.; Lago,Rochel M.Currently, approximately 1.4 billion tons per year of iron ore tailing wastes (IOT) are generated, mainly in Australia, Brazil, and China. This work describes the characterization and application of two typical IOT, i.e., fine and coarse wastes. The physicochemical characterization of these IOT by different techniques such as XRF (X-ray fluorescence), XRD (X-ray diffraction), Mössbauer spectroscopy, and granulo...
Serpentinites: Mineral Structure, Properties and Technological Applications
Carmignano,Ottavio Raul D. R.; Vieira,Sara S.; Brandão,Paulo Roberto G.; Bertoli,Alexandre C.; Lago,Rochel M.Serpentine is a versatile mineral family rich in Mg silicate with several polymorphic phases, mainly antigorite and lizardite, all of them with similar chemical composition (Mg3Si2O5(OH)4). Their structures are generally composed of octahedral layers rich in Mg[MgO2(OH)4]6- , attached to a tetrahedral silicate [Si2O5]2- sheet. The unique physicochemical properties of serpentinites and the existence of large res...
Potential Slow Release Fertilizers Based on K2MgSiO4 Obtained from Serpentinite
Ballotin,Fabiane C.; Santos,Wedisson O.; Mattiello,Edson M.; Carmignano,Ottávio; Teixeira,Ana Paula C.; Lago,Rochel M.In this work, a potassium magnesium silicate mineral based on phase K2MgSiO4 was prepared from serpentinite rock and studied as a potential K and Mg slow-release fertilizer. The material was prepared by impregnation of serpentinite/KOH and calcination at 700 °C to produce K2MgSiO4 phase, olivine and forsterite. The release patterns of K and Mg in the stirred-flow trial and leaching through the soil columns show...
New Magnetic Fe Oxide-Carbon Based Acid Catalyst Prepared from Bio-Oil for Este...
Ballotin,Fabiane C.; Almeida,Vitor F.; Ardisson,José D.; Silva,Márcio J. da; Soares,Ricardo R.; Teixeira,Ana Paula C.; Lago,Rochel M.In this work, bio-oil (an organic matrix rich in oxygen functionalities) was used to efficiently dissolve and disperse Fe3+ which upon thermal treatment produced a carbon containing dispersed and encapsulated Fe oxide magnetic nanoparticles. These materials were prepared by dissolution of 8, 16 and 24 wt.% Fe3+ salt in bio-oil followed by treatment at 400, 450, 500 or 600 ºC in N2 atmosphere. X-ray diffraction ...
Controlled Dehydration of Fe(OH)3 to Fe2O3: Developing Mesopores with Complexin...
Pinto,Paula S.; Lanza,Giovani D.; Ardisson,José D.; Lago,Rochel M.In this work, efficient adsorbents for β-lactam antibiotics based on mesoporous iron oxide containing surface [FeOx(OH)y] sites were produced by controlled precipitation of iron hydroxide and thermal treatment at 150, 200, 300 and 450 ºC (150FeOH, 200FeOH, 300FeOH and 450FeOH, respectively). Mössbauer, X-ray diffraction (XRD), thermogravimetry-mass spectrometry (TG-MS), Fourier transform infrared spectroscopy (...
Use of Amphiphilic Composites based on Clay/Carbon Nanofibers as Fillers in UHMWPE
Silva,Claudilene R.; Lago,Rochel M.; Veloso,Helena S.; Patricio,Patrícia S. O.In this work, it is proposed a new strategy to improve the dispersion of inorganic fillers in polymeric matrices by producing surface carbon nanostructures. Clay/carbon nanofibers particles were prepared and used as fillers to improve the mechanical and thermal properties of ultra-high molecular weight polyethylene (UHMWPE). Thermogravimetry (TG), differential scanning calorimetry (DSC), elemental analyses, Ram...
Solid State Reaction of Serpentinite Mg3Si2O5(OH)4 with NaOH to Produce a New B...
Paz,Gilvan M.; Vieira,Sara S.; Bertoli,Alexandre C.; Ballotin,Fabiane C.; Moura,Edmilson M. de; Teixeira,Ana Paula C.; Costa,Demétrio A. S.Solid state reaction of serpentinite Mg3Si2O5(OH)4 with NaOH was investigated to produce new NaMgSi oxide phases with basic properties for application in catalysis. X-ray powder diffraction (XRD) showed that NaOH impregnated on serpentinite, specially 20% sodium and treated at 700 ºC (20Na700), led to the formation of a new crystalline phase Na2Mg2Si2O7. This solid state reaction is discussed in terms of a firs...
Cellulose Nanocrystals Assembled on the Fe3O4Surface as Precursor to Prepare In...
Cunha,Igor T.; Teixeira,Ivo F.; Mesquita,João P.; Ardisson,José D.; Binatti,Ildefonso; Pereira,Fabiano V.; Lago,Rochel M.In this work, composites based on carbon (1, 10 and 20 wt.%) interfaced with Fe3O4 (magnetite) have been studied as catalysts for the oxidation of aqueous sulfide. The composites were prepared by assembling cellulose nanocrystals surrounding Fe3O4 followed by a controlled thermal decomposition at 400, 600 and 800 ºC. Mössbauer, X-ray diffractometry (XRD), Raman, thermogravimetry (TG), elemental analysis CHN, sc...