Quartz
Mostrando 1-12 de 528 artigos, teses e dissertações.
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1. Ultrafine quartz flocculation: Part I. System characterization and variables selection
Abstract A characterization study was performed to verify the more relevant physicochemical properties for quartz flocculation with polyacrylamide, as well as to define which variables should be further investigated regarding this flocculation system. Polyacrylamide was evaluated through molecular weight, radius of gyration, and infrared spectrometry. A natu
REM - International Engineering Journal. Publicado em: 2022
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2. Collector mixtures and their synergistic effect on quartz floatability
Abstract Sinergy is the interaction of two or more agents to produce a combined effect greater than the sum of their separate effects. Etherdiamine yields superior results for quartz floatability in a Hallimond tube and higher selectivity in the reverse bench scale cationic flotation of an iron ore, when compared to ethermonoamine. Blending these collectors
REM - International Engineering Journal. Publicado em: 2022
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3. MLA and optical microscopy as complementary techniques to the iron ore geometallurgical studies
Abstract Mineral liberation is an important variable to be considered in the iron ore geometallurgical studies, especially since it provides information leading to the understanding of the ore’s behaviour in the beneficiation process, mainly when harder ores are concerned. Nowadays, the professionals and researchers in the mineral industry have been using
REM - International Engineering Journal. Publicado em: 2022
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4. Thermostimulated crystal structure transformation of the polymineral clay submicron particles
Abstract Changes in the structure of phyllosilicate microparticles of submicron fractions of polymineral clay with an average size of 290 nm, as well as changes in the positions of impurity ions of transition metals in the crystal lattice, were studied by X-ray diffraction analysis, Fourier transform infrared spectroscopy, and high-resolution electron parama
Cerâmica. Publicado em: 2022
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5. Role of the reducing agent in tungsten extraction by chlorination with chlorine from an ore enriched by physical means
Abstract The effect of three reducing agents (sulphur dioxide, pyrite and carbon) on tungsten extraction from a scheelite-wolframite concentrate with chlorine gas was assessed. A low-grade ore (0.9% w/w WO3) was collected in the San Martín department, San Luis Province, Argentina, and subsequently enriched by physical means (65.73% w/w WO3). The minerals id
REM - International Engineering Journal. Publicado em: 2022
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6. Characterization of a complex carbonate-silicate apatite ore and its concentration by a two-stage anionic flotation method
Abstract A carbonate-silicate low weathering phosphate ore from an igneous origin deposit in Southeastern Brazil presents a challenge mainly for apatite flotation from its gangue minerals, calcite and dolomite, plus the presence of phlogopite, diopside, magnetite, richterite, ilmenite, vermiculite, quartz and many other minor impurities. Recently, selectivit
REM - International Engineering Journal. Publicado em: 2022
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7. Structural Characteristics of Lignite Char from Different Pyrolysis Reactors and the Influence on Their Gasification Reactivity
The gasification reactivity of coal char is affected by numerous experimental variables, and char structure is one of the dominant factors. In this work, Raman spectroscopy, powder X-ray diffraction (XRD), and N2 adsorption were used to investigate the physical and chemical structure of char prepared under different pyrolysis conditions. Three kinds of pyrol
Journal of the Brazilian Chemical Society. Publicado em: 2022
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8. Magnetic concentration route for recovering pellet feed fines stored in a mining dam
Abstract The greatest and noblest challenge of mining engineering for the present and the future of iron ore treatment could be considered as the pursuit of optimizing the use of mineral resources. The use of mining tailings, in the mineral sector itself, or in another industrial branch, meets the needs of circular economy as it increases the useful service
REM - International Engineering Journal. Publicado em: 2022
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9. Production of nanostructured crystalline composite using residual ashes from flocculated sludge burning process in a poultry slaughterhouse wastewater treatment system
Abstract Nanostructured crystalline composite (activated carbon) was synthesized from residual ashes of the burning process of the sludge generated in the flotation step of a poultry slaughterhouse and was used for Allura red dye adsorption. The ashes were chemically activated using two types of reagents, H2O2 and H3PO4, and the structure, morphology, and su
Cerâmica. Publicado em: 2022
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10. Polyacrylamides as co-depressant in hematite and quartz microflotation
Abstract In the present study, microflotation experiments were performed on pure minerals systems involving hematite and quartz in the presence of etherdiamine as collector. The influence of polyacrylamides as co-depressant was investigated in a blend with starch depressant. The results obtained demonstrated that all the polyacrylamides used were efficient i
REM, Int. Eng. J.. Publicado em: 2021-09
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11. Influence of the physical characteristics of sand and the crushed filler content on the properties of self-leveling mortars
Abstract The properties of self-leveling mortars (SLMs) in the fresh and hardened state are strongly affected by their formulation. In this study, the influence of three different quartz sands (different physical characteristics) was investigated in SLMs, as well as the replacement of these sands by crushed basalt filler. The tests performed were: spreading,
Cerâmica. Publicado em: 2021-06
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12. Purification of raw palygorskite: a comparative study involving different processes and dispersing agents
Abstract Palygorskite (Pal) is a natural clay mineral with fibrous morphology and high surface area. Depending on the geological origin, it presents impurities, such as quartz and carbonates, which can harm some of its properties. Therefore, this work seeks to define a viable methodology for the purification of a Brazilian Pal. Two types of mixing processes
Cerâmica. Publicado em: 2021-06