United Company RUSAL Engineering & Technology Centre LLC, Krasnoyarsk, Russia:

I. I. Lapaev, Manager, Associate Professor, Candidate of Technical Sciences, e-mail: iilapaev@yandex.ru
V. E. Polovnikov, Manager
A. M. Konstantinov, Manager

RUSAL Krasnoyarsk JSC, Krasnoyarsk, Russia:
V. E. Belyanin, Senior Foreman, DpPAM

The process of calcining coke in a rotary kiln is always associated with both inevitable and controlled coke losses. Inevitable losses occur due to both demoisturization and devolatilization, i.e. such losses are a function of the properties of a coke source. Controlled losses are a function of the following: calcination parameters, the condition of the exhaust gas duct system, and several green coke quality characteristics, such as coke granulometry and mechanical strength. The extent of losses defines the most important characteristic of the calcination process: Raw material (i.e. green coke) consumption per unit of output (i.e. calcined coke). As a rule, a material balance (MB) is established for the process of calcining petroleum coke, so that both raw material consumption and Calciner’s equipment condition can be assessed. So, the paper describes the activities that are aimed at measuring petcoke losses (actual losses) during calcination in a rotary kiln. (Empirically-determined MB items are listed.) This paper also covers quantitative data regarding petroleum coke losses that occur in the course of material (coke) flow through the Calciner’s equipment. The said data have been obtained by using both standard measuring tools (that are part of the Calciner’s process control system) and some additional measuring tools. The paper discusses the main reasons of carbon loss during calcination and provides for a number of possible measures to reduce the said losses. The MB results made it possible to determine the amount and composition of waste and by-products to evaluate the possibility of their further use and disposal. Based on the operation of several Calciners, it can be concluded the raw material consumption calculations have proved to be adequate and in compliance with actual values.

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