Breakthrough in magnesium processing could revolutionize the auto industry

[TexasTowelie]

Engineers at the University of Colorado Boulder have developed a more efficient spin on an old method of processing magnesium, and it could have huge implications for the auto industry.

-snip-

Magnesium, like most elements, does not exist by itself in nature. Instead, it comes in a state of raw ore, most commonly magnesia or dolomite. Processing pure magnesium out of its natural form is both energy-intensive and heavy on carbon emissions, which is where the problem lies.

Research assistant Mark Wallace explains the current processes: “You have electrolytic, which is a very clean process, but requires a bunch of energy, versus Pidgeon which is a lot easier to do but is very bad for the environment. We’re trying to find that middle ground where it’s still cost-effective and not so energy-intensive, but reducing gas emissions at the same time.”

-snip-

During World War II, the U.S. produced magnesium out of necessity to supply weapons and artillery manufactories, but profitability soon declined after the war and production was halted. However, the process used during this time provided the backbone for CU’s research team to develop a new and vastly improved version of the production method. Their study describes it as carbothermal reduction, which uses carbon as the reacting agent instead of ferrosilicon.

Read more: http://www.boulderweekly.com/boulderganic/breakthrough-magnesium-processing-revolutionize-auto-industry/

[eppur_se_muova]

1. Problem -- ever see a helicopter (largely Mg) crash and burn ? It's like a flashbulb.

Magnesium burns intensely hot (it's used in parachute flares and old flashbulbs), producing so much UV in the process it can deliver an instant sunburn as well as permanent retinal damage.

Magnesium fires can't be put out with CO2, either, because it just reacts with CO2. Mg burns even in pure N2. A volunteer firefighter once told me that after extinguishing a burning car with a Mg engine block (or was it wheels?) they could smell ammonia -- which is formed when Mg3N2, formed after the O2 in the vicinity has been consumed, reacts with water. So lack of O2 hadn't been enough to stop the fire !

Not sure how much of this I want rolling down the highway.

[hunter]

2. The density of magnesium is lower than aluminum...

... 1800 kg/m³ compared to aluminum's 2800 kg/m³ but known aluminum alloys are much stronger than magnesium alloys, which means less aluminum can be used to make parts of similar strength and weight.

Composite plastics (Kevlar, graphite...) also compete with magnesium.

Magnesium is easy to cast and machine, and it's also got some marketing panache, which is why it's used in such consumer goods as high end automobile wheels and expensive camera bodies.

Modern cars are increasingly aluminum and plastic.

[Javaman]

3. ...

[NNadir]

4. What exactly does this statement mean?

The Big Blue Technologies method promises to use less than half the energy (30 megawatt hours) of the dominant Pidgeon process (60-90 Mwh) and to emit about 50 percent less carbon dioxide.

30 MWh to produce how much?

In any case, carbothermal reductions are inherently batch processes which are almost always more expensive than continuous processes. It also matters whence the reductant (carbo...) comes.