Microwave Steelmaking

Makarand writes "Researchers at the Michigan Technological University are working on a low-cost steelmaking process which uses microwaves to heat iron ore instead of conventional heating. Their steelmaking facility was made of magnetrons from six household microwaves wired together and an electric arc furnace. When fed iron oxide and coal, the microwave energy could reduce the iron ore to iron within minutes and the electric arc furnace smelted the iron and coal into steel. The steel industry is taking a closer look at this new process which could cut steel production costs by upto 50%."

Comments

Re:Efficieny

[bluGill]

If you bursh up on your thermodynamics you will notice that simple fuels (say coal) cannot reach 50% efficency). Iron melts close to the flame tempature of some fuels. Run the calculations of efficency, and 50% looks really good.

Of course real industry uses electric a lot. However resisance (ohms law), while in theory 100% efficent has downsides. The heating elements are fragil, and that is assuming you can find one that doesn't melt at less than the tempature of liquid iron. Typically carbon arc furances are used, which means you replace carbon rods once in a while.

Induction heating is common in industry. I'm not sure where, or for what purposes, but I know it is used. I don't know how it compares to this process.

Implications for other planets?

[Anonymous Coward]

Since this technique is a lot more efficient than using conventional methods, how feasible would it be to make a portable steelmaking machine? Say.. that was small enough to be lifted by rocket to another planet.

The idea being, of course, that you feed rock and electricity in one end of a smallish box and get steel out the other. Would this be useful for making a base on the moon or mars? Huh?

I read the article and I'm confused...

[HotNeedleOfInquiry]

The article talks about replacing the blast furnace with this microwave-based device and using it to make steel. Well, a blast furnace doesn't make steel, it makes pig iron, a different and much less useful material. According to what I've read, another process such as a bessemer converter is needed to turn the pig iron into steel.

I seem to recall that you have to blow hot air or oxygen through the melt to burn out excess carbon to convert the pig iron to steel. Maybe he hasn't gotten that far developing the process.

If indeed he has found a way to go from ore straight to steel, this is a pretty valuable process. There just isn't enough information to tell.