A Method for the Rapid Characterization of Petroleum Coke Microstructure Using Polarized Light Microscopy
Petroleum coke is used for the fabrication of anodes for aluminum reduction cells. There are ever-increasing economic and supply availability pressures for alternative and multiple sources and qualities for fabricating anodes, and therefore for cost effective characterization to make timely adjustments of the anode mixes. One characteristic historically acknowledged as having a significant detrimental influence on anode thermo-mechanical properties is the so-called isotropic structure. Traditionally such characterizations using optical microscopy are exhaustive and therefore cause a throughput concern. A method was developed and successfully applied to green and calcined coke reducing the interpretation time of a sample down to about twenty minutes. The sample preparation and interpretation methodology is described and examples presented, including a case study of how the method was used to guide raw material blend decisions across Rio Tinto Alcan’s North American sites.
KeywordsCoke Anode Structure Microscopy
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