Silicate Minerals
Mostrando 1-12 de 29 artigos, teses e dissertações.
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1. 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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2. Influence of Mn2+ ions on depression of quartz and spessartine in gondite ore
Abstract Low-grade manganese ores that are composed of manganese oxides, wad, quartz, iron oxides, gibbsite, and especially of spessartine (Mn3Al2(SiO4)3) are known as gondite. Spessartine is a mineral with a high content of silica (SiO2) and alumina (Al2O3) that causes a decrease of the enrichment in manganese oxide concentrates by flotation, giving this o
REM, Int. Eng. J.. Publicado em: 2021-01
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3. Cationic flotation of smithsonite and dolomite from Brazilian Ambrósia Norte Deposit
Abstract The flotation of low-grade oxidized zinc ores has been commonly used to produce marketable concentrates for many years. Several flotation routes are being successfully used: cationic, anionic and a mixture of anionic and cationic. The choice of the route taken is dependent on the major zinc-bearing minerals in the deposit of interest and its associa
REM, Int. Eng. J.. Publicado em: 16/09/2019
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4. Determination of maximum zinc recovery of Vazante mine ore by flotation process
Abstract Nowadays, Nexa Resources (ex-Votorantim Metais) operates two zinc mines in Brazil, represented by the Vazante unit in Vazante - MG and the Morro Agudo unit in Paracatu - MG. The present study was carried out at the Vazante unit, where zinc concentrate is produced from a silicate ore called Willemite (Zn2SiO4) through froth flotation processes. The t
REM, Int. Eng. J.. Publicado em: 2019-06
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5. Identification of Heavy Metals in Crystals of Sand and Silt Fractions of Soils by Scanning Electron Microscopy (SEM EDS/WD-EPMA)
ABSTRACT Studies of heavy metals are concentrate on clay fractions, but coarser fractions of the soil can constitute significant sources of structural forms of heavy metals. The aim of this study was to evaluate the occurrence of heavy metals in the structure of minerals of the sand and silt fractions of soils from three different parent materials (metamorph
Rev. Bras. Ciênc. Solo. Publicado em: 08/03/2018
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6. Impact of an Alkaline Solution on the Chemistry, Mineralogy, and Sorption Properties of a Typic Rhodudult Soil
Abstract The preferred option for disposal of short-lived low and intermediate level radioactive wastes is a near surface disposal facility in which soil is one of the barriers that avoid radionuclide migration outside the controlled area. For construction of that kind of facility, concrete is widely used, and its interaction with water induces its degradati
Rev. Bras. Ciênc. Solo. Publicado em: 09/11/2017
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7. Pedogenic Iron Oxides in Iron-Rich Oxisols Developed from Mafic Rocks
ABSTRACT Despite the considerable amount of information on the mineralogical characteristics of pedogenic Fe oxides in Brazilian soils, there are few studies on Fe-rich soils developed from mafic rocks with taxonomic identities at lower categorical levels. This study evaluated the mineralogical characteristics of pedogenic Fe oxides in B horizons (Bw) of Fe-
Rev. Bras. Ciênc. Solo. Publicado em: 27/04/2017
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8. Paralavas in the Cretaceous Paraná volcanic province, Brazil - A genetic interpretation of the volcanic rocks containing phenocrysts and glass
ABSTRACT The occurrences of glassy rocks containing long and curved phenocrysts in the Paraná volcanic province, South America, are here interpreted as paralavas. The large number of thin (0.1-0.5 m) dikes and sills of glassy volcanic rocks with hopper, hollow or curved, large crystals of clinopyroxene (up to 10 cm), plagioclase (up to 1 cm), magnetite and
An. Acad. Bras. Ciênc.. Publicado em: 2016-12
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9. Concentration of manganese tailings via reverse flotation in an acid médium
Abstract Beneficiation of manganese ores has been conducted around the world by circuits composed basically of crushing, screening and spiral classifier. Therefore, solely the coarse size fractions (and commonly the richest) are actually recovered: "lump" (-75+9mm) and "sinter feed" (-9+0.15mm). In the industrial plant which processes the ore from the Azul M
Rem: Rev. Esc. Minas. Publicado em: 2016-03
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10. Effect of inorganic and organic depressants on the cationic flotation and surface charge of rhodonite-rhodochrosite
Abstract Silicates (rhodonite, tephroite, spessartine) and the carbonate (rhodochrosite) of manganese are of economic interest in silicate-carbonated manganese ores. The recovery of both mineral classes by flotation constitutes a challenge; rhodochrosite is a slightly soluble mineral that can release Mn2+ ions in pulp. In this work, the effects of inorganic
Rem: Rev. Esc. Minas. Publicado em: 2015-12
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11. A técnica de difração de elétrons retro-espalhados (EBSD) em microscópio eletrônico de varredura (MEV) e sua aplicação no estudo de rochas deformadas
The electron backscattered diffraction technique in the scanning electron microscope (EBSD/SEM) is based on the diffraction of a high-energy electron beam by the crystalline structure of a given material, in all possible directions within the sample. Some of the diffracted electrons escape from the specimen with virtually the same initial energy, interact wi
Publicado em: 2010
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12. Study of alkali-silica reaction gel in concrete by high-resolution nuclear magnetic resonance / Estudo da reação álcali-sílica em concretos através de ressonância magnética nuclear de alta resolução
The alkali-silica reaction (ASR) occurs between structurally distorted or disordered silica and aqueous solutions of alkaline hydroxides, as KOH or NaOH. The product of the ASR is an alkali-silicate gel, which may expand upon water absorption. When the ASR occurs in mineral aggregate used in concrete, the process of reaction and expansion cause the decrease
Publicado em: 2009