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

Science can do anything!

[Zemrec]

First they find the cure for cancer is the common cold, and now they can put metal in a microwave!! Maybe next they'll find the cause of belly button lint.

Good news, if it works

[ctr2sprt]

This is great news for US steelmakers. Like all other industries that rely on unskilled labor, steel manufacturers have been in a prolonged slump while business moves overseas. If this works out, we can implement it and become competitive again.

You see, free trade can do good things for the average worker. Though to be fair "good things" in this case means fewer steelworkers will lose their jobs instead of all of them. Still, it's improvement, and who knows? If our costs really drop by 50%, demand very well could increase enough to justify keeping all the old workers around.

(I didn't really have anything to say, but the only other posts with scores higher than zero were... Well, if you've been on Slashdot for more than five minutes, you know what they were like.)

Re:Good news, if it works

[bluGill]

Not nessicarly. Most third world countries don't have reliable power. If you have molten iron, and the power goes out, you have to empty everything fast, because once it solidifies it will crack the containers when you try to remove it. (as it cools it contracts, when you melt it, it expands. think frozen water)

Remember too that energy is cheap in the US. I doupt any third world country really has a major advantage there. Perhaps Iceland, with all their geo-thermo, they have already locked up aluminium, but are they third world?

There are a lot of issues. If you want a custom shape from your supplier it is much easier to get it from one in your town than a third world nation. If your factory is automatied enough, labor costs aren't significant anyway, (it is all skilled labor which you would have to import to the third world country) so what is the point in moving.

Most of the "japanese" car manufactors have factorys in the US. You can have a profitable manufactoring company in the US, if you run it right.

Re:Good news, if it works

[bluGill]

Right, unfortunatly water is a strange thing, acting very different from most other materials. It hits the minimun density at about 4 degrees C. That is it contracts as it cools until it gets 4, then it starts expanding.

Iron does in fact contract when it solidifies. As it contracts it pulls more and more iron (okay a very tiny amount more) in. When you heat something containing solid iron, that iron needs to go someplace. Heat from the bottom of a container, and the bottom will melt first, and expand, but there is solid iron above it, so something has to give. Often that is the container.

My liege?

[NanoGator]

" The steel industry is taking a closer look at this new process which could cut steel production costs by upto 50%"

I'm glad somebody finally hit that research button. I can't make any more villagers.

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.

Re:For america lets hope not

[Anonymous Coward]

This story is yet another example of what makes the USA great.

The inventor, Jiann-Yang (Jim) Hwang, came from Taiwan to the U.S. to pursue his graduate studies. (Here's his resume.) He graduates from Purdue with a Ph.D., and 20 years later, he's a professor of materials science at Michigan Technological University, and is adding to the collective innovating efforts of our nation.

Personally, I'm all for smart, hard-working people immigrating to the U.S. and staying here. All those temp workers in the technical industry who have come over here from India? All those people from Ecuador who are willing to work like dogs in the restaurant industry? All those people from Eastern Europe who are filled with the entrepreneurial sprit? Don't give them visas, make them citizens!

since no one else jumped on this one

[maddh]

...eliminating the need for high-cost coke.

finished rehab?

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.

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

[Drishmung]

Even so, steel is very cheap to manufacture. By the ton, it is one of the cheapest structural materials. And I mean mild steel here, not pig iron. By contrast, Al and it's alloys are far more expensive, and plastics even more so.

However, most people are not very interested in mild steel by the ton. They want manufactured goods, and there things change. The hardness, toughness and high melting point of steel make it relatively expensive to manufacture. So much so that it's not really worth re-cycling iron scrap in small quantities---the raw material is so cheap that the processing and transportation costs make it uneconomic. It's easy to re-cycle beer cans though---just melt them at (relatively) low temperature and you have your raw material back for much less than it costs to process bauxite.

Plastics, despite the high raw material cost are typically extremely cheap to manufacture (though often expensive to recycle for various reasons).

So, if you can halve the cost of making mild steel, or even the cost of making pig iron, that's not going to add up to a lot of saving on the cost of your new car. It won't even halve the cost of the product leaving the steel factory's gates, since that product is , AFAIK, not 'raw' steel, but some form of at least partially manufactured product such as steel plate at the very least.

Oh Yeah Great

[Anonymous Coward]

This may be a big timesaver, but, unfortunately, this process gives the steel a rubbery texture, and the middle always comes out frozen.

Not Exactly New

[core plexus]

I remember reading about using microwaves for certain refractory ores, I'm pretty sure one of them was "Microwave Heating of Chemicals and Minerals", 1995. They have also used microwaves in the treatment of gold ore, and microwaves for the embrittlement of coal. I haven't heard of it being used on any but a lab scale yet, though.

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