- Method ASTM D5184
- Repeatability 0.2968*X**2/3
- Reproducibility 0.7890*X**2/3
- Blending linear
- Additive Correction No
The purpose of this test is to determine the amount of Aluminum and Silicon in Residual Fuel Oils. The amounts covered in the method are between 5 and 150 mg/kg for Aluminum and 10 and 250 mg/kg for Silicon.
Aluminum and Silicon are present in the catalysts used during the refining process. While the catalyst is not consumed in the process there are small pieces called fines that can contaminate the fuel. This in turn causes excessive wear in the engines that use the fuel.
The method is performed by first weighing up a piece of the fuel to be analyzed in a Platinum crucible. The sample is then burned off until only the heavy carbon is left. Once this is complete the sample is placed into a muffle furnace to completely rid the crucible of carbon leaving only the metals behind. The sample is then fluxed to fuse the metal ash in the furnace. After this is performed it is broken down into a water based solution using acid. Finally the sample will be aspirated using an Atomic Absorption Instrument. Both the sample, and a standard set are run to accurately determine the levels.