Research and Development > JFE TECHNICAL REPORT > No.13 Special Issue on “Ironmaking Technology” and “Slag Products” > Development of Carbon Iron Composite Process

No.13 Special Issue on “Ironmaking Technology” and “Slag Products”

Development of Carbon Iron Composite Process

ANYASHIKI Takashi     FUKADA Kiyoshi     FUJIMOTO Hidekazu

Abstract

In recent years, the development of innovative energy saving technologies for preventing global warming has become necessary. Means of realizing innovative energy saving in the steel manufacturing process and radical low reduction agent ratio (RAR) operation in the blast furnace include improvement of the heat balance and active control of the reduction equilibrium (temperature of thermal reserve zone). As a means of realizing low RAR operation, this paper describes the development of an innovative raw material “ Carbon Iron Composite” for satisfying both high coke reactivity and iron ore reduction, focusing on the temperature of the thermal reserve zone. Carbon Iron Composite is produced by mixing coal and iron ore (pellet feed) and densification by hot briquetting, followed by carbonization of the briquetted materials. The results of a fundamental investigation of the production process for Carbon Iron Composite as a new blast furnace burden material obtained by carbonization of the densified briquettes clarified the following: (1) It was possible to form briquettes as raw material for Carbon Iron Composite by hot briquetting without using a binder. (2) The possibility of producing Carbon Iron Composite with a compression strength of more than 2 000 N using a mixture of 40% iron ore and 60% coal was confirmed. The reduction ratio of the product exceeded 70%. (3) Carbon Iron Composite has a coke reactivity index (CRI) of more than 50% and displayed a typical surface reaction. Melting and separation phenomena were not observed after heat treatment at 1 700°C.

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