Clay Mineral
Mostrando 1-12 de 117 artigos, teses e dissertações.
-
1. Phase transformation of kaolinite to hexagonal kalsilite using K2CO3
Abstract Hydrothermal synthesis of kalsilite was facilitated by the inclusion of potassium carbonate (K2CO3) as the source of the potassium ion. After a 24 h reaction at 220 °C, kaolin clay treated with 1.25 M K2CO3 showed the most significant peaks at 2θ of 28.5° and 34.7° by X-ray diffraction corresponding to the hexagonal kalsilite. In addition, field
Cerâmica. Publicado em: 2022
-
2. 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
-
3. Brazilian Mineral Clays: Classification, Acid Activation and Application as Catalysts for Methyl Esterification Reactions
In this study, three raw Brazilian clays from João Pessoa, Paraíba State (Aço AP, AVL and Verde Lodo) were characterized before and after purification and acid activation. Several instrumental techniques were used, and the raw clays were classified as dioctahedral smectites with different compositions, where the AVL sample had the highest content of montm
J. Braz. Chem. Soc.. Publicado em: 2021-01
-
4. BIONANOCOMPÓSITOS POLIMÉRICOS À BASE DE MONTMORILLONITA – MATERIAIS DE INTERESSE CONTÍNUO
Polymeric bionanocomposites are versatile materials that have many practical applications. The wide use of these materials is mainly due to their structure and properties, which combine at nanometric scale, the functionality of biopolymers with the excellent stability of inorganic solids, such as the clay minerals family. Montmorillonite is the most widely e
Quím. Nova. Publicado em: 2020-12
-
5. Mineralogical characterization of copper lateritic ore from the Furnas deposit - Carajás, Brazil
Abstract Furnas is a small and not well-known copper sulfide deposit in the northern Carajás mineral province (Pará State, Brazil). Mineralogical and geochemical studies were performed on three weathered samples in order to verify the presence of copper in the lateritic minerals. According to these Cu-bearing minerals (malachite, e.g.), the weathered ore c
REM, Int. Eng. J.. Publicado em: 2020-09
-
6. Assessment of sulfamethoxazole adsorption capacity on Pirangi clay from the State of Sergipe, Brazil, modified by heating and addition of organic cation
Resumo O sulfametoxazol (SMX) é um antibiótico amplamente usado no tratamento de doenças e infecções e é frequentemente detectado em ecossistema de águas superficiais. Assim, este trabalho avaliou a capacidade de remoção deste antibiótico de sistemas aquosos utilizando argila Pirangi (PIR) do estado de Sergipe (Brasil). Amostras de argila Pirangi f
Cerâmica. Publicado em: 14/11/2019
-
7. Transport of Atrazine Via Leaching in Agricultural Soil with Mineral Oil Addition
RESUMO: Os adjuvantes, como os óleos minerais, são amplamente utilizados na aplicação de herbicidas por reduzir a deriva e a evaporação das gotas, bem como por aumentar a absorção do herbicida pela planta. Contudo, pouco se sabe como o óleo mineral se comporta quando em contato com o solo. Assim, o objetivo desta pesquisa foi avaliar o transporte de
Planta daninha. Publicado em: 17/10/2019
-
8. Influence of reactivity and mineralogical composition on instability due to the disintegration of shales from Paraíba and Ceará States, Brazil
Resumo Este trabalho teve como objetivo correlacionar a reatividade e composição mineralógica de folhelhos à sua desintegração. Para tanto, foram caracterizadas cinco amostras de folhelho das Bacias do Rio do Peixe e Araripe, localizadas nos estados brasileiros da Paraíba e Ceará e, para fins de comparação, foi utilizada uma amostra de argila bento
Cerâmica. Publicado em: 15/08/2019
-
9. PEDOGENESIS ON COASTAL TABLELANDS AREA WITH LOW RANGE ALTIMETRY IN PARAÍBA STATE
RESUMO Pequenas variações de relevo influenciam na drenagem e no escoamento superficial, contribuindo para a formação de horizontes superficiais arenosos e subsuperficiais endurecidos (fragipãs e, ou, duripãs) em solos dos Tabuleiros Costeiros. Este trabalho investigou a pedogênese em área de Tabuleiros Costeiros com baixa amplitude altimétrica no E
Rev. Caatinga. Publicado em: 18/07/2019
-
10. Carbon in Physical Fractions and Organic Matter Chemical Composition of an Acrisol after Amazon Forest Burning and Conversion into Pasture
The aim of this study was to investigate impacts of Amazon Forest (AF) fire and conversion to pasture on carbon accumulation in particle size fractions and organic matter (OM) composition of an Acrisol. Soil samples were collected (0.00-2.00 m depth) in three sites: native AF (NAF); AF under natural regeneration for two years after burning (BAF); 23-years ol
J. Braz. Chem. Soc.. Publicado em: 2019-02
-
11. Influencia del calcio en la retención de humedad por arcilla
ABSTRACT Bentonite as a raw material is an economical alternative to produce desiccants. The literature indicates that it is a good water adsorbent in relation to the desiccants commonly used in industry (silica gel, molecular sieve). In this sense, it is a valid alternative and an economic option since the clay is a natural compound, which makes it environm
Matéria (Rio J.). Publicado em: 19/07/2018
-
12. Molecular dynamics studies of amylose plasticized with Brazilian Cerrado oils: part I
Abstract Biodegradable polymers have become part of the realm of polymer science with specially when associated to renewable sources. Unraveling the plasticizer effect of natural occurring fatty acids in the Brazilian Cerrado on amylose oligomers was aimed in this work in an aqueous environment. Since the interactions within a material are of extreme import
Polímeros. Publicado em: 28/06/2018