ISO 6245 pdf download.Petroleum products — Determination of ash
1 Scope
This International Standard specifies a method for the determination of the ash content of petroleum products, such as distillate and residual fuel oils, crude petroleum, lubricating oils, waxes and other petroleum products, in which any ash-forming constituents present are normally considered to be undesirable impurities or contaminants. Ash can result from oil-soluble or water-soluble metallic compounds or from extraneous solids such as dirt and rust. The method is applicable to products having ash contents in the range 0,001 % (m/m) to 0,180 % (m/m), but does not apply to products which contain ash-forming additives, including certain phosphorus compounds. The analysis of unused or used lubricating oils containing additives, used engine crankcase oils, lubricating oils containing lead, or certain non-hydrocarbon diesel fuels, should be determined using ISO 3987 1) , which includes a step to produce sulfated ash of higher melting point. NOTE 1 For the purposes of this International Standard, the term “% (m/m)” is used to represent the mass fraction of a material. NOTE 2 With certain types of samples, the test results may not account quantitatively for all the metal compounds capable of forming an ash. Some unused lubricating oils and distillate fuel oils contain metal inorganic additives of low molecular mass (e.g. sodium, potassium), where the metal oxide may sublime below the temperatures specified in this International Standard.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 3170:1988, Petroleum liquids — Manual sampling ISO 3171:1988, Petroleum liquids — Automatic pipeline sampling ISO 4259:1992, Petroleum products — Determination and application of precision data in relation to methods of test ISO 5272:1979, Toluene for industrial use — Specifications
7 Sample preparation
7.1 General Before transferring the test portion to be ashed to the evaporating vessel (5.1), ensure that the sample in its container is homogeneous by one of the procedures described in 7.2 or 7.3. 7.2 Mobile samples Mix mobile samples to distribute particulate material, such as catalyst fines, rust or adventitious particulates, throughout the sample evenly. Increasing mixing intensity is used until visual homogeneity is observed. Mixing by manual or mechanical shaking for 10 min is the lowest intensity mixing procedure, followed by repeated and longer mixing times. When it is evident that repeated or lengthy shaking is not achieving homogeneity, use the mixer (5.5) for the minimum time to make the sample homogeneous. If the sample cannot be satisfactorily homogenized, discard and obtain a new sample. 7.3 Viscous or solid samples Heat samples of viscous, semi-solid and solid materials at room temperature until they are sufficiently mobile to mix by the procedures given in 7.2 (see the note below). Take great care if the heating required is likely to be above 90 °C, as any water in the sample may boil causing spattering or foaming. Wear appropriate safety goggles and gloves. Use an oven or hot-water bath to heat the sample container containing the sample. As a first mixing procedure, stirring with a rod that reaches the bottom of the container is the lowest intensity first mixing step. NOTE A minimum temperature approximately 5 °C above the pour point of the material is normally required to achieve adequate mobility for mixing.