What is XRD analysis used for?
X-ray diffraction analysis (XRD) is a technique used in materials science to determine the crystallographic structure of a material. XRD works by irradiating a material with incident X-rays and then measuring the intensities and scattering angles of the X-rays that leave the material [1].
How do you identify clay minerals?
Clay minerals are most often identified by reflection powder XRD of both oriented and random preparations. Identification is greatly facilitated if the clay fraction is first separated from the rock (bulk sample), to minimize contamination by non-clay minerals.
What is the chemical equation for clay?
Kaolinite is a clay mineral of chemical formula Al2O3 2SiO2·2H2O that has a structure of 1:1 uncharged dioctahedral layer where each layer consists of single silica tetrahedral sheet and single alumina octahedral sheet [123,124].
How do you read XRD analysis?
To check the nature of the materials using XRD patterns, you have to look the nature of Bragg’s peaks appearing in the XRD pattern. If you get a very broad humped peak, then the material will be amorphous with short range ordering. If you get sharp peaks ii the XRD pattern, then the material is crystalline.
How do you identify clay minerals in XRD?
Identification of Clays using XRD Basal reflections give d-spacing of the basal layer which represent the thickness of the silicate layers and the unit cell often contains multiple layers. Clay mineral peaks can generally be distinguished by the width halfway up the peak (i.e. the full width at half maximum, FWHM).
What are the 4 properties of clay?
The small size of the particles and their unique crystal structures give clay materials special properties. These properties include: cation exchange capabilities, plastic behaviour when wet, catalytic abilities, swelling behaviour, and low permeability.
What are the 6 stages of clay?
There are 6 essential stages of clay:
- 1. ) Slip. Slip is clay with added water to make it into a paste or liquid.
- 2.) Wet clay. Wet clay is used by many potters to produce their work.
- 3.) Leather-hard clay.
- 4.) Dry clay.
- 5.) Bisque.
- 6.) Glaze ware.
What are the advantages of XRD?
The main advantages of x-ray diffraction are: It is a rapid and powerful technique for identifying unknown minerals and materials. It only requires preparation of a minimal sample for analysis. Interpreting the resulting data is relatively straightforward.
What are the properties of clay mineral?
Why are clay minerals hard to quantify?
However, the quantification of clay minerals remains complex relative to the quantification of other minerals as clay minerals have unique structures, such as various polytypes and types of defects, and can vary in chemical composition and in terms of effects of preferred orientation (Środoń, 2002).
What is hardness of clay?
Specific gravity of most clay minerals are within the range from 2 to 3.3. Their hardness generally falls below 2.5. Refractive indices of clay minerals generally fall within a relatively narrow range from 1.47 to 1.68. Generally the size and shape, the two properties, are determined by electron micrographs.
What are the 5 stages of clay?
The 6 different stages of clay
- 1. ) Slip. Slip is clay with added water to make it into a paste or liquid.
- 2.) Wet clay. Wet clay is used by many potters to produce their work.
- 3.) Leather-hard clay. When wet clay has dried slightly but is not fully dry it is known as ‘leather-hard’.
- 4.) Dry clay.
- 5.) Bisque.
- 6.) Glaze ware.
How to prepare clay for XRD analysis?
Black sink to dispose acid solution XRD analyses on clay separation requires several preparation steps: Removing carbonates (to better identify the clay minerals) Suspending material particles (to separate the < 2 μm clay size fraction from the rest of the particles)
Does the preferred orientation affect XRD reflection intensities of clay minerals?
The XRD reflection intensities of clay minerals are usually enhanced by the preferred orientation ( Lippmann, 1970) and thus the preferred orientation is believed to be a major source of error in quantitative analysis of clays minerals ( Środoń et al., 2001 ).
How does the matrix effect affect X-ray diffraction analysis of clay minerals?
In quantitative X-ray diffraction analysis of clay minerals, analysis accuracy is affected by the matrix effect arising from the unique structures of clay minerals. Theoretically, this matrix effect can be described as follows:
Why characterisation of the clays is important?
Adequate characterisation of the clays is becoming increasingly important as operating mines move into areas of more complex mineralogy, and new mines commence with more complex ores.