ISO 20203:2005 pdf download.Carbonaceous materials used in the production of aluminium Calcined coke Determination of crystallite size of calcined petroleum coke by X-ray diffraction.
ISO 20203 is based on ASTM D5187-91(2002)[61 published by ASTM International, 100 Barr Harbor Drive, P0 Box C700, West Conshohocken, PA 19428-2959, United States.
ASTM D5187-91(2002) was developed under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants as the direct responsibility of Subcommittee D02.05.OD on Petroleum Coke Sampling and Procedures, and was published in December 1991.
The crystallinity of petroleum coke, as reflected by the L. value, is a general measure of quality affecting suitability for end use and is a function of the heat treatment used.
The crystallite height is used to determine the extent of such heat treatment, for example, during calcination. The value of the L. determined is not affected by coke microporosity or the presence of foreign, noncrystalline materials such as dedust oil.
Carbonaceous materials used in the production of aluminium Calcined coke Determination of crystallite size of calcined petroleum coke by X-ray diffraction
SAFETY PRECAUTIONS — ISO 20203 does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of ISO 20203 to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
ISO 20203 describes a test method for the determination of the mean crystallite height of a representative, pulverized sample of calcined petroleum coke by interpretation of an X-ray diffraction pattern produced through conventional X-ray scanning techniques.
It applies to carbonaceous materials used in the production of aluminium.
Calcined petroleum coke contains crystallites of different heights. This test method covers the determination of the average height of all crystallites in the sample by empirical interpretation of the X-ray diffraction pattern. The crystallite diameter (La) is not determined by this test method.
2 Terms and definitions
For the purposes of this document, the following terms, abbreviated terms and definitions apply.
2.1
crystallites
stacks of graphitic carbon platelets located parallel to one another
4.1 Xray powder diffractometer, equipped with an X-ray source set for Cu-Ka radiation, a monochromator or filter for restricting the wavelength range, a sample holder, a radiation detector, a signal processor, and readout (chart or computer memory). The diffractometer shall be capable of rate scanning at 1°/mm or incrementally step scanning at 0,2°/step.
4.2 Sample holders, as specified by the manufacturer of the diffractometer, that enable packing of a pulverized sample of sufficient height to expose a level, smooth surface to the X-ray beam.
4.3 Briquetting press, capable of generating pressures up to 70 MPa.
4.4 Compressible aluminum caps, used as a support for producing a briquetted sample.
4.5 Silicon or quartz sample, of reference material quality suitable for calibrating the diffractometer.
NOTE These materials are usually available from national reference organizations e.g. the National Institute of
Standards and Technology in USA.
5 Reagents and materials
Use only reagents of recognized analytical grade and only distilled water or water of equivalent purity (see [1],
Weigh out 4,0 g of the sample onto a watch glass and pipette exactly 3 ml of the binding agent onto the sample and mix thoroughly with a spatula. Place the sample under an infrared-heat lamp and allow the acetone to evaporate. Typically, about 1 or 2 mm will be required to eliminate the acetone odour from the sample. Break up the caked sample with a spatula and transfer to an aluminum cap whose diameter is compatible with the sample holder of the diffractometer. Place the cap in a briquetting press and press at 48 MPa. Transfer the pelletized sample to the sample holder and insert into the diffractometer for analysis.
7 Calibration
7.1 Ensure that the diffractometer is in correct mechanical and optical alignment and that intensities have been maximized through the procedures described in the instrument manufacturer’s documentation. A service engineer or in-house technician who has been well instructed in the correct alignment procedures suggested by the manufacturer best accomplishes this.
7.2 Monitor proper angles and intensities with the reference silicon or quartz sample and take corrective actions if necessary.ISO-20203-2005