BS ISO 23201:2015 pdf free

BS ISO 23201:2015 pdf free.Aluminium oxide primarily used for production of aluminium – Determination of trace elements
A flat, level heat sink is required to cool hot charged moulds. Using both an aluminium and ceramic heat sink is effective, where initial cooling is achieved on the ceramic heat sink and quicker cooling to ambient temperature is achieved on the aluminium heat sink.
Alternatively, commercially available automatic fusion machines may be used since the development of modern automated fusion equipment has made bead preparation faster and significantly less operator-dependent. Most of these machines use similar sized crucibles and moulds to those described in the manual method and simulate the action required to ensure complete dissolution of the sample in the molten flux. The use of these devices to prepare fused beads is acceptable as long as the agitation provided is sufficient to ensure complete dissolution of the samples and that it can be demonstrated that the results so generated achieve the accuracy and precision criteria outlined in Clauses 11 and 12.
Bulk samples shall be taken in accordance with AS 4538.1 and test samples prepared in accordance with AS 4538.2 Weighed test portions are extracted from test samples and may be dried or analysed as-received. As-received samples often contain up to 3 % moisture and proper drying requires a 300 °C treatment. Procedures for this are contained in ISO 806.
It is possible to fuse and produce borate discs from as-received test samples. However alumina used for aluminium production ty pically contains a few mass per cent of particles greater than 150 micron,consequently better repeatability is often achieved by grinding in a vibratory mill (5.6). Grinding is recommended if coarse impurities are present from the manufacturing process. Examples of these contaminants are refractory fragments from the calcination process or quartz particles not removed during refining.
Calibration is performed using a two-point regression. Determine the zero concentration point from a blank calibration disc of flux and high purity Al2O3, and the high concentration point from a synthetic calibration disc (SCD) derived from flux and an intermediate calibration glass (ICG). Make a correction for the loss of mass on fusion of the flux, by establishing a value for the loss on fusion of each batch of flux.BS ISO 23201 pdf free download.