Thermogravimetry/evolved water analysis (TG/EWA) combined with XRD for improved quantitative whole-rock analysis of clay minerals in sandstones

Clay Minerals ◽  
1995 ◽  
Vol 30 (1) ◽  
pp. 27-38 ◽  
Author(s):  
D. M. Thornley ◽  
T. J. Primmer
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Water Analysis ◽  
Infrared Detector ◽  
Size Fraction ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Northern North Sea ◽  
Rock Analysis

AbstractCurrent methods of quantitative whole-rock clay mineral analysis of sandstones often provide little more than an estimate of clay mineral abundances, especially where the total clay mineral content is <10 wt% of the sandstone. More accurate determinations of clay mineral abundance in the whole rock can be made by combining thermogravimetry/evolved water analysis (TG/EWA) and X-ray diffraction (XRD) data. The TGA/EWA system incorporates a purpose built thermobalance linked to a water specific infrared detector which is used to measure quantitatively the clay mineral dehydroxylation water evolved from the whole rock when heated from 250°C to 900°C. This gives a measure of the total hydroxyl content of the clay minerals in the whole rock which, when combined with XRD analysis of a separated clay size-fraction, enables individual clay mineral abundances in the whole-rock sample to be determined. Results on artificial sand/clay mineral mixtures prepared with known amounts of different clay minerals (chlorite, illite and kaolinite) show that the accuracy of the combined method is most influenced by the accuracy of the XRD data. Errors associated with TG/EWA were found to be negligible by comparison. A case study is included in which the technique has been used to determine accurately the illite abundance in the Magnus Sandstone Reservoir, Northern North Sea.

Quantitative XRD bulk and clay mineralogical determination of paleosol sections of Unayzah and Basal Khuff clastics in Saudi Arabia

2012 ◽  
Vol 27 (2) ◽  
pp. 126-130 ◽  
Author(s):  
Shouwen Shen ◽  
Syed R. Zaidi ◽  
Bader A. Mutairi ◽  
Ahmed A. Shehry ◽  
Husin Sitepu ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Mixed Layer ◽  
Size Fraction ◽  
Xrd Analysis ◽  
Ratio Method ◽  
Type I ◽  
Rock Formations ◽  
Refinement Method

Quantitative X-ray diffraction (XRD) analysis is performed on 172 samples mainly containing paleosol sections of Unayzah and Basal Khuff clastics taken from the core of one well drilled by Saudi Aramco. Quantitative XRD bulk mineralogical determination is achieved using the Rietveld refinement method whereas quantitative XRD clay mineralogical determination of clay-size fraction is obtained using the reference intensity ratio method. The XRD results indicate that the samples from paleosol sections consist mainly of quartz and feldspar (microcline and albite) as framework constituents. Cement minerals include dolomite, hematite, anhydrite, siderite, gypsum, calcite, and pyrite. Clay minerals are important constituents in paleosols. The XRD results show that clay minerals in the samples are illite, mixed-layer illite/smectite, kaolinite, and chlorite. No discrete smectite is present in the samples. The clay mineral associations in these samples of paleosol sections can be classified into three types: Type I predominantly consists of illite and a mixed layer of illite/smectite; Type II of kaolinite; and Type III of illite and a mixed layer of illite/smectite, but also significant amounts of kaolinite. The change of clay mineral association type with sample depth can indicate the change of paleoclimate and paleoenvironment. For example, kaolinite usually forms under strongly leaching conditions such as abundant rainfall, good drainage, and acid waters. Therefore, XRD mineralogical data of paleosol sections are important for petroleum geologists to study paleoclimate and paleoenvironment and to predict the reservoir quality of the associated rock formations.

Hydrolysis of ceramic materials: neoformation or rehydroxylation of clay minerals. Oxygen stable isotope analysis

Clay Minerals ◽  
2002 ◽  
Vol 37 (2) ◽  
pp. 345-349 ◽  
Author(s):  
R. Nuñez ◽  
J . Capel ◽  
E. Reyes ◽  
A. Delgado
Keyword(s):  
Oxygen Isotope ◽  
Clay Minerals ◽  
Isotope Composition ◽  
Isotope Analysis ◽  
Size Fraction ◽  
Ceramic Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fired Bricks ◽  
Oxygen Stable Isotope

AbstractHand-made bricks were manufactured from natural sediments by firing at 700°C and 800°C after which they were hydrothermally altered at 150°C in a high-pressure reactor for 1200 h. Sediments and fired pieces were studied by X-ray diffraction. The <2 μm size-fraction of fired and hydrolysed samples were also studied by X-ray diffraction and oxygen isotope analysis. The oxygen isotope composition of the samples became depleted in 18O by alteration. Our results are consistent with a process of hydration and hydroxylation of the partially destroyed clay minerals in the fired bricks. The work is relevant to understanding the origins and alteration processes in old ceramic materials.

Quantitative X-ray diffraction analysis using clay mineral standards extracted from the samples to be analysed

Clay Minerals ◽  
1967 ◽  
Vol 7 (1) ◽  
pp. 79-90 ◽  
Author(s):  
Ronald J. Gibbs
Keyword(s):  
Diffraction Analysis ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Internal Standard ◽  
Ethanol Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Density Separation ◽  
Calibration Curves ◽  
Differential Settling

AbstractIn the quantitative X-ray diffraction analysis of a series of samples, the problems arising from the variable compositions and degrees of crystallinity of clay minerals were overcome to a great extent by the use of standards extracted from the samples. Procedures are given for separation of the montmorillonite standard by differential settling of Na-montmorillonite solvated in an ethanol solution and for isolation of the kaolinite, mica, and chlorite standards by density separation of their Na-forms in thallous formate.Calibration curves were prepared from the X-ray diffractograms obtained for series of known mixtures of Ca-forms of the standards and the internal standard boehmite using both powder and smear-oriented mounting techniques.

Corrigendum - Transformations of clay minerals in black earth and red loams of basaltic origin.

1954 ◽  
Vol 5 (1) ◽  
pp. 98
Author(s):  
JA Ferguson
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Soil Types ◽  
X Ray Diffraction ◽  
X Ray ◽  
Partial Decomposition ◽  
Red Soils ◽  
Eastern Australia

The development in the Toowoomba area, Queensland, of red, black, and transitional soil types from basalt is typical of similar processes in many parts of eastern Australia. Systematic samples from this area have been investigated mineralogically by differential thermal analysis, X-ray diffraction, and other methods. Montmorillonite appears to be the clay mineral first formed under present weathering conditions. The further transition to red soils in certain situations is due to partial decomposition of montmorillonite to minerals of the kaolin group by loss of alkalis and iron, the latter being stabilized in the upper horizons as hydrated oxides. Further decomposition of kaolin minerals produces gibbsite. Changes in the nature and amount of clay minerals are thought to correspond with stages in the evolution of basalt soil types.

Transformations of clay minerals in black earth and red loams of basaltic origin.

1954 ◽  
Vol 5 (1) ◽  
pp. 98
Author(s):  
JA Ferguson
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Soil Types ◽  
X Ray Diffraction ◽  
X Ray ◽  
Partial Decomposition ◽  
Red Soils ◽  
Eastern Australia

The development in the Toowoomba area, Queensland, of red, black, and transitional soil types from basalt is typical of similar processes in many parts of eastern Australia. Systematic samples from this area have been investigated mineralogically by differential thermal analysis, X-ray diffraction, and other methods. Montmorillonite appears to be the clay mineral first formed under present weathering conditions. The further transition to red soils in certain situations is due to partial decomposition of montmorillonite to minerals of the kaolin group by loss of alkalis and iron, the latter being stabilized in the upper horizons as hydrated oxides. Further decomposition of kaolin minerals produces gibbsite. Changes in the nature and amount of clay minerals are thought to correspond with stages in the evolution of basalt soil types.

Qualitative and quantitative mineralogical composition of the Rupelian Boom Clay in Belgium

Clay Minerals ◽  
2015 ◽  
Vol 50 (2) ◽  
pp. 249-272 ◽  
Author(s):  
E. Zeelmaekers ◽  
M. Honty ◽  
A. Derkowski ◽  
J. Środoń ◽  
M. De Craen ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Quantitative Composition ◽  
Bulk Rock ◽  
X Ray Diffraction ◽  
Rock Composition ◽  
X Ray ◽  
Boom Clay ◽  
Bulk Rock Composition ◽  
Clay Formation

AbstractThe Boom Clay Formation of early Oligocene age, which occurs underground in northern Belgium, has been studied intensively for decades as a potential host rock for the disposal of nuclear waste. The goal of the present study is to determine a reference composition for the Boom Clay using both literature methods and methods developed during this work. The study was carried out on 20 samples, representative of the lithological variability of the formation. The bulk-rock composition was obtained by X-ray diffraction using a combined full-pattern summation and singlepeak quantification method. Siliciclastics vary from 27 to 72 wt.%, clay minerals with 25–71 wt.% micas, 0–4 wt.% carbonates, 2–4 wt.% accessory minerals (mainly pyrite and anatase) and 0.5–3.5 wt.% organic matter. This bulk-rock composition was validated independently by majorelement chemical analysis. The detailed composition of the clay-sized fraction was determined by modelling of the oriented X-ray diffraction patterns, using a larger sigma star (σ*) value for discrete smectite than for the other clay minerals. The <2 μm clay mineralogy of the Boom Clay is qualitatively homogeneous; it contains 14–25 wt.% illite, 19–39 wt.% smectite, 19–42 wt.% randomly interstratified illite-smectite with about 65% illite layers, 5–12 wt.% kaolinite, 4–17 wt.% randomly interstratified kaolinite-smectite and 2–7 wt.% chloritic minerals (chlorite, “defective” chlorite and interstratified chlorite-smectite). All modelled clay mineral proportions were verified independently using major-element chemistry and cation exchange capacity measurements. Bulkrock and clay mineral analysis results were combined to obtain the overall detailed quantitative composition of the Boom Clay Formation.

SOME PODZOL SOILS OF ALBERTA

1960 ◽  
Vol 40 (1) ◽  
pp. 1-14 ◽  
Author(s):  
S. Pawluk
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Diffraction Data ◽  
Strong Evidence ◽  
Clay Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Components ◽  
Mixed Layering ◽  
Podzol Soils

Recent exploratory surveys in the northern sections of Alberta revealed many soils morphologically similar to podzols. A laboratory study was carried out to obtain a better understanding of the genesis and morphology of these soils.Chemical analyses showed the percentage base saturation and pH to be higher than for typical podzols.Physical analyses showed slight increases in clay content in the B horizons and decreases in the A horizons when compared to the parent material.From mineralogical studies of the profiles, the following weathering sequences were established: feldspars>quartz; chlorite>biotite>muscovite; [Formula: see text]. X-ray diffraction data showed illite, montmorillonite-illite mixed layering, montmorillonite, and kaolinite as being the principal clay minerals present in the A and C horizons. The clay mineral components of the B horizons were primarily chlorite-like with lesser amounts of kaolinite. Analyses indicated that the chlorite-like mineral lacked properties attributed to well crystallized chlorites and provided strong evidence in favour of authigenic origin.Data obtained in this study showed the genesis of these soils to be somewhat different from that reported for podzols elsewhere although the process of formation evidently was primarily chemical.

Complex permittivity and clay mineralogy of grain-size fractions in a wet silt soil

Geophysics ◽  
2008 ◽  
Vol 73 (3) ◽  
pp. J1-J13 ◽  
Author(s):  
Steven Arcone ◽  
Steven Grant ◽  
Ginger Boitnott ◽  
Benjamin Bostick
Keyword(s):  
Grain Size ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Complex Permittivity ◽  
Mineral Content ◽  
Size Fraction ◽  
Clay Mineralogy ◽  
Free Water ◽  
Size Fractions ◽  
Grain Size Fractions

We determined the complex permittivity and clay mineralogy of grain-size fractions in a wet silt soil. We used one clay-size fraction and three silt-size fractions, measured permittivity with low error from [Formula: see text] with time-domain spectroscopy, and estimated mineral weight percentages using X-ray diffraction (XRD). The volumetric water contents were near 30%, and the temperature was [Formula: see text]. For the whole soil, standard fractionation procedures yielded 2.4% clay-size particles by weight, but XRD showed that the phyllosilicate clay minerals kaolinite, illite, and smectite made up 17% and were significantly present in all fractions. Above approximately [Formula: see text], all real parts were similar. Below approximately [Formula: see text], the real and imaginary permittivities increased with decreasing grain size as frequency decreased, and the imaginary parts became dominated by direct-current conduction. Similarly, below approximately [Formula: see text], the measured permittivity of montmorillonite, a common smectite, dominated that of the other clay minerals. Total clay mineral and smectite mass fractions consistently increased with decreasing grain size. Below [Formula: see text], a model with progressively increasing amounts of water and parameters characteristic of montmorillonite matches the data well for all fractions, predicts permittivities characteristic of free water in smectite structural galleries, and shows that the similar real parts above [Formula: see text] are caused by a small suppression of the high-frequency static value of water permittivity by the smectite. We conclude that the clay mineral content, particularly smectite, appears to be responsible for permittivity variations between grain-size fractions. Small model mismatches in real permittivity near the low-frequency end and the greater fractions of kaolinite and illite suggest that the total clay mineral content might have been important for the coarser fractions.

scholarly journals XRD-Thermal Combined Analyses: An Approach to Evaluate the Potential of Phytoremediation, Phytomining, and Biochar Production

2019 ◽  
Vol 16 (11) ◽  
pp. 1976 ◽  
Author(s):  
Dario Fancello ◽  
Jessica Scalco ◽  
Daniela Medas ◽  
Elisa Rodeghero ◽  
Annalisa Martucci ◽  
...  
Keyword(s):  
Thermal Analyses ◽  
Xrd Analysis ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Juncus Acutus ◽  
Polluted Sites ◽  
Synchrotron Light ◽  
In Situ Heating

A method for evaluating the potential of reuse of biomasses for economic purposes is here presented starting from a case study. Juncus acutus plants and rhizospheres were harvested from abandoned Zn–Pb mine areas of southwest Sardinia (Italy). Thermogravimetry and Differential Thermal analyses were performed to evaluate the temperatures at which significant reactions occur. X-ray Diffraction (XRD) analysis was carried out on raw samples and on samples heated ex-situ (by a conventional diffractometer) or in-situ (by synchrotron-based diffraction). Raw samples mainly consist of quartz, phyllosilicates, and feldspars with minor amounts of sulfides, sulfates, and Fe, Pb, and Zn carbonates, concentrated in the rhizosphere. After heating, Zn and Fe oxides and willemite are observed in internal roots and stems, revealing the presence of these metals in the plant tissues. In-situ heating was less effective than ex-situ in revealing minor phases in organic samples, probably because the scarcity of oxygen within the sample holder did not allow the degradation of organic compounds and the oxidation of sulfides, resulting in a low quality XRD signal even if obtained with the high resolution ensured by a synchrotron light source. This method can be applied to plants from polluted sites for metal exploitation, and/or to biomasses from unpolluted sites for biochar production, since both applications take advantage of the knowledge of the minerals formed after heating.

scholarly journals Clay mineralogy of landslide occurrences in hydrothermally altered area: A case study of Durensari Area, Purworejo, Central Java

2019 ◽  
Vol 76 ◽  
pp. 02008
Author(s):  
Ilham Dharmawan Putra ◽  
Anastasia Dewi Titisari ◽  
Hitznaiti Zaidini Khul Husna
Keyword(s):  
Clay Minerals ◽  
Volcanic Rocks ◽  
Clay Mineralogy ◽  
X Ray Diffraction ◽  
Landslide Occurrence ◽  
Central Java ◽  
Argillic Alteration ◽  
Replacement Process ◽  
Propylitic Alteration

Landslide is one of the geological phenomena that can be found frequently in Indonesia, where several areas are damaged due to landslide occurrence. One of it is located in Durensari Area, Bagelen, Purworejo, Central Java as the study area. The study area is characterized by the presence of altered volcanic rocks formed by the tertiary eruption, followed by hydrothermal alteration that contains clay minerals that could enhance the landslide occurrence. This study is conducted to identify hydrothermal clay minerals that which enhanced the landslide in the study area. Field mapping is done as field observation, as well as the clay minerals are identified from 10 samples using X-Ray Diffraction (XRD) as the study method. The observation has resulted that there are at least ±25 landslide occurrence points in the study area, which is associated with alteration type that consists of several clays, named by smectite, kaolinite, and illite assemblages as argillic alteration and chlorite, smectite, illite, and kaolinite assemblages as propylitic alteration. The research concluded that the replacement process of primary minerals by clay minerals and the presence of smectite affect the landslide occurrence in the study area, where moderate to the large landslide is associated with Argillic alteration, meanwhile small to moderate landslide is associated with propylitic alteration.

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