Characterisation and Corrosion of Laboratory Scale Briquettes of Reduced Iron

Abstract

While considerable work has been reported in literature on the corrosion behaviour and products of direct reduced iron and sponge iron, very little work has been reported on hot briquetted iron, particularly on the effects of the conditions under which the iron ore is reduced and briquetting parameters have on subsequent corrosion behaviour of briquettes.
To investigate this, a laboratory briquetter produced briquettes from finely granulated direct reduced iron (DRI), under pressures of up to 160 MPa and at temperatures up to 700°C. Briquetting variables such as heating time, temperature at which compaction takes place, pressure applied and atmosphere under which briquetting took place were all strictly controlled.
Influences of the briquetting parameters of temperature and pressure during compaction on the density and surface area of the HBI were established. Characterised briquettes were then utilised in a study of reoxidation behaviour of hot briquetted iron under various conditions including temperature and salt contamination to simulate storage and transportation related conditions. The studies have established that the influence of reduction and briquetting parameters and the oxidation environment variables of temperature and salt contamination are significant factors in understanding briquette corrosion.