ASTM D6969-17 pdf free.Standard Practice for Preparation of Calcined Petroleum Coke Samples for Analysis.
Determine the required analyses for the lot and man-age the division steps accordingly to achieve enough analyticalsample to perform all required analyses in duplicate (seeflowchart in Fig. 1 as an example). Divide the gross sample byuse of a riffle or rotary sample divider to an intermediatesample of sufficient mass.
Exercise care in the division operation to preserve theparticle size distribution of the gross sample. Riffle openingsmust be at least three times the top size of the calcinedpetroleum coke being divided. A feed hopper or vibratoryfeeder，or both，are recommended to feed the coke into theriffle. Enclosed riffles are recommended to minimize dustingand loss of sample.
Crushing processes are to be carried out such that theapparatus does not contribute significant impurities into theanalysis sample. For example, if trace metal analyses are to beperformed on a number 60 mesh analysis sample, a ring and puck mill with tungsten carbide grinding components isrecommended to minimize the metallic impurities of analyticalinterest that may be added to sample.
If trace metals are not required for testing on a number60 mesh analysis sample, a bench-top hammer mill or ball millare adequate for performing the grinding operation.Refer to actual test methods for size and mass ofsamples required for analysis.
Removal of dedusting oil may be required for analyticalpurposes and for subsequent analyses such as real density orporosity. Oil may be extracted and quantified by Test MethodD4930 or thermally removed.
Mixing of gross samples to generate a composite samplerepresenting more than one lot is frequently required. Mixingmust be planned such that the final composite sample has amass of no less than 10 kg so that all the required analyses maybe performed.
Divide each gross sample down into an intermediatesample weighing no less than 1.5 kg such that each intermediate sample is still representative for sizing determination byTest Method D5709.ASTM D6969 pdf download.