Carbothermal Reduction of Iron Ore Applying Microwave Energy

Abstract

This paper presents the results of a study on carbothermal reduction of iron ore made under the microwave field in equipment specially developed for this purpose. The equipment allows the control of radiated and reflected microwave power, and therefore measures the microwave energy actually applied to the load in the reduction process. It also allows performing energy balances and determining the reaction rate with high levels of confidence by simultaneously measuring temperature and mass of the material upon reduction with high reproducibility. We used a microwave generator of 2.45 GHz with variable power up to 3000 W. Self‐reducing pellets under argon atmosphere, containing iron ore and petroleum coke, with 3.5 g of mass and 15 mm of diameter were declined. We obtained the kinetic curves of reduction of iron ore and of energy consumption to the process in the maximum electric field, in the maximum magnetic field and at different values of power/mass. The data allow analyzing how the microwave energy was actually consumed in the reduction of ore.

Microwave-assisted metallurgy

“…82 A recent study also suggested that the reduction reaction between iron ore and petroleum coke was highly dependent on microwave heating characteristics of the materials, whose effects could be evaluated by simultaneously measuring temperature and mass of materials during reduction. 83 Figure 10 shows a schematic of the microwave heating system for iron ore reduction in argon, in which two directional couplers were used. By using the couplers ('1' and '2' in Fig.…”

“…Schematic of microwave iron ore reduction system 83 (reproduced with permission of John Wiley and Sons)…”

“…Schematic of microwave iron ore reduction system83 (reproduced with permission of John Wiley and Sons)Peng and Hwang Microwave-assisted metallurgy International Materials Reviews…”

A helicopter view of microwave application to chemical processes: reactions, separations, and equipment concepts

“…A recent work in our group (Sturm et al 2013a) showed that they enable experimentation with a morphologically simple and predictable microwave field and that systems based on these waveguides allow for adaptable process conditions. Moreover, this type of cavity system has already been used in a number of studies for chemical activation with microwave fields (Toukoniitty et al 2009, de Castro et al 2012, Patil et al 2012). …”