Thermal characteristics and phase transformation of iron ores containing varied crystalline water with coal mixtures

Abstract

Iron ore, with high combined water such as goethite, is widely spread in Indonesia. This is not commonly used as the main raw material in iron and steel making pr0Cess. However, as iron ore resources are getting limited and decreasing in number, iron making industries have to seek other iron ore sources, such as low-grade iron ore goethite ore. The purpose of this research is to investigate the thermal characteristics of composite iron ore containing high combined water, coal, and synthetic goethite ore as comparing samples using the thermogravimetric method. This research is conducted with several experimental conditions: heating from 25-1200°C; heating rate 10°C/minute; nitrogen (inert) furnace atmosphere. The composition is divided into two parts, which are composite A and composite B with 24% and 16% coal, respectively. The results showed that wustite and solid iron formations at a temperature of 973°C; 1050°C and 990°C; 1060°C, respectively. This is because there is more coal composition on composite A so that composite B needs a higher temperature to produce CO as reducing agent. In general, for all mixtures, the reactions 0Ccurred from lower temperature are dehydration, dehydroxylation, the formations of Fe2O3 (hematite), Fe3O4 (magnetite), wustite (FeO), and Fe Metal.