A METHOD FOR THE RAPID CHARACTERIZATION OF PETROLEUM COKE MICROSTRUCTURE USING POLARIZED LIGHT MICROSCOPY

摘要

Petroleum coke is used for the fabrication of anodes for aluminumreduction cells. There are ever-increasing economic and supplyavailability pressures for alternative and multiple sources andqualities for fabricating anodes, and therefore for cost effectivecharacterization to make timely adjustments of the anode mixes.One characteristic historically acknowledged as having asignificant detrimental influence on anode thermo-mechanicalproperties is the so-called isotropic structure. Traditionally suchcharacterizations using optical microscopy are exhaustive andtherefore cause a throughput concern. A method was developedand successfully applied to green and calcined coke reducing theinterpretation time of a sample down to about twenty minutes.The sample preparation and interpretation methodology isdescribed and examples presented, including a case study of howthe method was used to guide raw material blend decisions acrossRio Tinto Alcan’s North American sites.