Quality assessment of foundry coke

Abstract

Possible methods for quality assessment of foundry coke are evaluated with a view to predicting the smelting characteristics and the properties of the cast iron produced. This involves defining what is meant by the quality assessment of foundry coke; a literature review of existing methods of coke assessment; and the identification of possible methods for the quality assessment of foundry coke. Analysis in terms of the macrostructure, the electrical resistance, the structure of the cast iron in a cupola furnace, and the coke consumption indicates that compliance with State Standard GOST 3340-88 does not ensure satisfactory quality of foundry coke. The quality of foundry coke may be assessed in terms of the yield of volatiles, the reactivity, the mean piece size, the macroporosity, and the electrical resistance. The resistance is greatest for samples in the size class 40–60 mm and is least for the size class 60–80 mm. It increases with increase in the moisture, ash, and sulfur content. Quality assessment may be based on the content of 0.3 mm, and 0.2–0.3 mm), and also on the structural parameters of the cast iron: the shape and size of the graphite inclusions, which depend on the ash content, total sulfur content, and total moisture content in the coke. Voluntary certification may be used for the quality assessment of foundry coke.