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Publikācija: Behavior of Illite Clay Mineral by Differential Treatments

Publication Type Conference paper
Funding for basic activity Unknown
Defending: ,
Publication language English (en)
Title in original language Behavior of Illite Clay Mineral by Differential Treatments
Field of research 2. Engineering and technology
Sub-field of research 2.5 Materials engineering
Authors Mārtiņš Randers
Gaida Maruta Sedmale
Ingunda Šperberga
Aija Krūmiņa
Keywords Illite, treatment, ceramic materials
Abstract Illite is one of the most common clay mineral in earth surface environments. Its definitions and characterization criteria heave fluctuated [1]. Commonly illite is described as a clay mica with a general composition of [KxAlx(Si4-xAlx)O10 (OH)2 (where 0.75<x<0.9). Structural illite belong to sheet silicates where structural units consist two Si-O tetrahedral sheets always joined with an octahedral Al-O sheet. Conceptually this is accomplished by having the apical oxygen anions of the tetrahedral References 1.A.Meunier, B.Velde, Illite: Origin, Evolution and Metamorphism. Springer, New York, 2004. 2.Chuan, Hui Zhou, J.Keeling, Appl. Clay Sci.,74, (2013) pp.3-9.. sheet formed part of immediately adjacent octahedral sheet. To accomplish this, an OH– from the octahedral sheet must be removed to make a room for each apical oxygen anion from tetrahedral sheet. Both sheets are combined to form layers known as 1:1 and 2:1 layers. One of more investigated processes to attain an increased compressive strength of clay minerals containing materials is by proper mix development with highly alkaline solution [2]. Although for this preparation the mainly used is 1:1 layer lattice alumosilicates, i.e., geopolymers, it is also of interest 2:1 minerals such as 2:1 illite. The aim of this study is to show how the chemical, mechanical, hydrothermal and thermal treatment condition influenced the structure and some properties of treated illite, as well as impact of its on development of dense high–temperature ceramics. For all types of treatment there are used illite separated from State importance illite clay deposit Apriki. Clay fraction-illite, from Apriki clay were separated using sedimentation and chemical methods. For characteristic not treated and treated illite as well as sintered ceramic samples there was used X-ray diffraction analysis (XRD-model Rigaku, Japan, and D8 Advance Bruker AXS), as well as SEM Nova-Nano 650 (FEI Netherlands). To perform elementary (oxide) analysis for illite X-ray spectrometer S4 PIONEER (Bruker AXS) was used. Differential thermal analysis (Setaram, SETSYS Evolution-1750) was applied to characterize the phases change by thermal treatment of illite. It is shown that effective is the thermal, at temperature ~ 600° C and chemical by 6M NaOH, treatment. Thermal treatment yield homogenous illite powder with particles having almost spherical shape, which would promote sintering. Chemical treatment by 6M NaOH lead to formation of a new crystalline phase –sodium aluminosilicate hydrate -Na(AlSiO4)6·H2O, which pervades illite. Thermal treated illite was used for new compositions development with Al(OH)3. After sintering samples at 1000-1100°C with 40 % Al(OH)3 additive there was found that compressive strength of ceramics reaches value 168 N/mm2.
Reference Randers, M., Sedmale, G., Šperberga, I., Krūmiņa, A. Behavior of Illite Clay Mineral by Differential Treatments. In: 7th International Conference on Silicate Materials "BaltSilica 2016", Lithuania, Kaunas, 26-27 May, 2016. Kaunas: Kaunas University of Technology, 2016, pp.49-50.
ID 23343