Clays
Mostrando 25-36 de 187 artigos, teses e dissertações.
-
25. Hydrometallurgical extraction of Al and Si from kaolinitic clays
Abstract Herein is presented the results of a study on the hydrometallurgic extraction and recovery of aluminum and silicon by leaching of kaolinitic clays with HF. The studied extraction parameters were: temperature, reaction time, solid/liquid ratio, concentration, and precipitating agent mass. In the leaching process, mineral dissolutions near 100% were o
REM, Int. Eng. J.. Publicado em: 2017-12
-
26. Characterization and Evaluation of Ceramic Properties with Spherical and Prismatic Samples of Clay Used in Red Ceramics
The Brazilian red ceramic industry monthly consumes about 10.3 million tons of clay, its main raw material. In most potteries, characterization of the clay is made empirically, which can result in roof tiles and blocks not according to standards. In this sense, this paper aims to characterize clays used in the manufacturing of red ceramic products in a facto
Mat. Res.. Publicado em: 09/11/2017
-
27. PHB/Bentonite Compounds. Effect of Clay Modification and Thermal Aging on Properties
Poly(3-hydroxybutyrate) (PHB) was compounded with three different Bentonite clays: natural, purified by ultrasound/sonicated and organically modified with hexadecyltrimethylammonium bromide. PHB/Bentonite masterbatches with 30% clay were prepared in a laboratory internal mixer and letdown with pure matrix to 1% and 3% w/w clay. Test samples were injection mo
Mat. Res.. Publicado em: 21/08/2017
-
28. Evaluation of the Mechanic and Electrochemical Properties of an Epoxy Coating with Addition of Different Polyhedral Oligomeric Silsesquioxanes (POSS) Applied on Substrate of Low Alloy Steel
The epoxy resin is one of the matrices most employed in obtaining composites and coatings. Its properties have been modified using materials such as clays and polyhedral oligomeric silsesquioxanes - POSS. The use of POSS in the preparation of thermosetting nanocomposites has been studied in obtaining hybrid materials with higher mechanic and surface properti
Mat. Res.. Publicado em: 31/07/2017
-
29. Clays for Brick Manufacturing in Actopan, Hidalgo: Physical, Chemical and Mineralogical Characterization
Samples of clays from Actopan, Hidalgo employed in brick manufacturing are physical, chemical and mineralogical characterized. Transmitted polarized light microscopy showed a uniform particle size with grain morphology characteristic of euhedral crystals with quartz, feldspars, nontronite, and iron oxides particles. Scanning Electron Microscopy revealed 75 �
Mat. Res.. Publicado em: 11/05/2017
-
30. Smectite Clay Modified with Quaternary Ammonium as Oil Remover
Clays such as smectite have high technical and economic viability due to their large adsorption capacity. These properties can be improved by treatment with acids or other modifications. This paper describes experiments to prepare and characterize organoclays and to evaluate their ability to remove oil from contaminated water in comparison with clay in its n
J. Braz. Chem. Soc.. Publicado em: 2017-02
-
31. Estudo de novas ocorrências de argilas plásticas (ball clays) do nordeste do Brasil para uso em cerâmicas refratárias
Resumo A região nordeste do Brasil possui grandes depósitos de argilas plásticas do tipo ball clay situados geralmente na Formação Barreiras e são usados em cerâmica branca e materiais refratários. Essas argilas são constituídas por caulinitas secundárias e matéria orgânica, sendo muito plásticas e quando submetidas a elevadas temperaturas quei
Cerâmica. Publicado em: 2016-12
-
32. HÍBRIDOS DE QUITOSANA-ARGILA PARA ENCAPSULAMENTO E LIBERAÇÃO SUSTENTADA DO FERTILIZANTE NITRATO DE POTÁSSIO
The use of controlled release fertilizers is a trend for improving productivity, reducing costs and environmental pollution. Such materials release gradually the nutrients to the plant in order to supply its requirement and are an alternative to improve fertilization. The preparation of a microsphere from natural materials (chitosan and montmorilonite clay)
Quím. Nova. Publicado em: 2016-12
-
33. MOLECULAR VALIDATED MODEL FOR ADSORPTION OF PROTONATED DYE ON LDH
Abstract Hydrotalcite-like compounds are anionic clays of scientific and technological interest for their use as ion exchange materials, catalysts and modified electrodes. Surface phenomenon are important for all these applications. Although conventional analytical methods have enabled progress in understanding the behavior of anionic clays in solution, an e
Braz. J. Chem. Eng.. Publicado em: 2016-03
-
34. The Use of Montmorillonite Clays as Reinforcing Fillers for Dental Adhesives
The aim of this study was to obtaining an adhesive made of dimethacrylate copolymer and clay particles in different concentrations. The samples were prepared by light curing and were evaluated by XRD, FTIR and TGA as well as by measuring flexural strength, elasticity modulus and tensile resistance. The XRD and the mechanical test results indicated that the s
Mat. Res.. Publicado em: 12/02/2016
-
35. Effect of the loading of organomodified clays on the thermal and mechanical properties of a model dental resin
Experimental dental resins composed of triethyleneglycol dimethacrylate, urethane dimethacrylate, ethoxylated bisphenol-A-dimethacrylate and bisphenol A glycidyl methacrylate containing an organoclay as filler were prepared by photopolymerization. The addition of organoclay fillers results in slower polymerization rates (0.59 and 0.24 mol L-1 min-1, for the
Mat. Res.. Publicado em: 05/02/2016
-
36. Sterile Clay Pozzolans from Phosphate Mining
The work presents the characterization of clays from sterile mining of the concentrated phosphatic materials of Araxá in Minas Gerais as pozzolanic materials. Three clays of distinct tones, namely, yellow (YC), red (RC), and intermediate (IC) clays, were used at different levels of excavation depth. The clays were calcined at three temperatures (680, 760, a
Mat. Res.. Publicado em: 17/11/2015