Evolution of anode grade coke quality

Abstract

The petroleum refining industry has historically categorized petroleum cokes as fuel, anode, or needle grade cokes. The term “anode grade coke” has been used as a broad definition by the aluminum industry to describe delayed coke with a sponge structure containing relatively low levels of metals like vanadium (typically <400ppm) and low to moderate levels of sulfur (0.5-4.0%). These classifications are less relevant today due to the much wider range of cokes used in anode blends. This paper will present a review of the growing range of coke qualities used in anode blends. Shortages of traditional quality anode coke are driving calciners and anode producers to use cokes with a much wider range of properties. Cokes previously regarded as unsuitable for anode production are being used routinely in blends at varying levels and this trend will continue. Examples are given on how smelters are dealing with changing coke quality.