Greener steel maldng process by microwave irradiation with discharges

Highly pure pig irons were produced from powdered iron ores and carbons in a multimode microwave reactor. Microwaves create two different steps that enhance chemical reactions at the grain boundaries very rapidly to finish the reduction process. The visible light spectroscopic monitored the progress of the reactions. The powders absolve and radiate the continuous spectrum of blackbody emission under the temperature of 650degC. The magnetic fields couples directly and heats to the ores in this process. At above 650degC, the small hot spots rise, move and finally the microscopic arcing spots burst in to all over the surface emitting with brighter line spectrums. Carbon nitride molecules and Fe (I) atoms were identified in the recorded spectrum. These bursts are similar to the "ignition propagation" that is observed in chemical reactions. The line spectra originated from CO molecules have not been detected yet. The solid-solid reaction could be expected between the iron oxides and carbon to produce CO₂ directly. A loss in the sample weight was accelerated during the excess-emission. These are the clear evidence that microwaves cause thermally non-equilibrium state and accelerate reduction process. The electric field of microwave plays an important role in the second step. Microwave energy penetrated into the powder matrix and made small arcing between the powders. The electrons got kinetic energy from the microwave electric field and the accelerated electrons gave the kinetic energy to the powders. It looks similar process to the electric arc furnace. However, the difference was that the microwave carried the electric field energy directly in to the powder matrix and created high temperature electrons just in the powders. The conversion efficiency from the plasma electrons to ores could be expected to be 100% theoretically. The reduction of iron ore is completed at 1380degC and very pure pig iron was remained. The impurity level of Mg, S, Si, P and Ti was on- - ly 5-10% of what was found in the pig irons produced by modern conventional blast. The amount of carbon was half to produce the unit weight of pig iron in comparison to conventional blast. If we applied renewable energy or nuclear power plants to generate the microwaves, we can save 6% of carbon exhaust in the steel making industries. Several hundreds megawatts microwave systems will be required to replace all the existing classic blast furnaces all in the worlds.