A Novel Microwave and Induction Heating Applicator for Metal Making: Design and Testing

Abstract

The use of microwave heating in primary metallurgy is gaining an increasing interest due to the possibility to selectively process ores and to volumetrically heat large amounts of low-thermal conductivity minerals. In this paper the study, development and testing of a new applicator combining the use of microwave and induction heating for rapid reduction of metal containing oxides is described. Numerical simulation was used in order to achieve the proper control over heat generation, considering the use of microwave solid state generators. A prototype, with a capacity up to 5 liters of standard input feed but with the predisposition for continuous processing has been designed, built and tested on reference loads like iron oxide powders and pellets. Results on the microwave heating part of the applicator indicate that it allows to efficiently and rapidly process these kinds of loads, which change from dielectric to conductors as reduction proceeds. The use of variable frequency solid state microwave generators allows to maximize energy efficiency and to controllably change the heating pattern inside the load.

Pelletization and sintering of New Zealand titanomagnetite ironsand

“…The use of microwaves exhibits unique advantages such as rapid, volumetric, and selective heating, which can reduce process times and energy consumption [77], [78]. This is due to the different heating mechanism in microwave processing compared to conventional processing.…”

A Numerical Study on the Performance of the H2 Shaft Furnace with Dual-Row Top Gas Recycling

“…This preliminary assessment confirmed that the dual-row injection TGR system could improve the furnace performance, especially in terms of gas utilization degree and total energy demand. Recently, the state-of-the-art technology of microwave heating that has attracted widespread attention in the field of pyro-metallurgy [12,13] has appeared as an option of supplying thermal energy to the H 2 -SF. However, there is so far very little information on the use of microwave heating in shaft furnaces.…”