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This Lab-Made Mineral Just Became a Key Candidate For Reducing CO2 in The Atmosphere
Scientists just worked out a way of rapidly producing a mineral capable of storing carbon dioxide (CO2) - giving us a potentially exciting option for dealing with our increasingly overcooked planet. Magnesite, which is a type of magnesium carbonate, forms when magnesium combines with carbonic acid - CO2 dissolved in water. If we can produce this mineral at a massive scale, it could safely store large amounts of carbon dioxide we simply don't need in our planet's atmosphere.
[...] Being able to make the mineral in the lab could be a major step forward in terms of how effective carbon sequestration might eventually be. "Using microspheres means that we were able to speed up magnesite formation by orders of magnitude," says [Ian] Power. "This process takes place at room temperature, meaning that magnesite production is extremely energy efficient."
[...] With a tonne of naturally-occurring magnesite able to capture around half a tonne of CO2, we're going to need a lot of magnesite, and somewhere to put it all as well. As with other carbon capture processes, it's not yet clear whether this will successfully scale up as much as it needs to. That said, these new discoveries mean lab-made magnesite could one day be helpful – it puts the mineral on the table as an option for further investigation.
Related: Negative Emission Strategy: Active Carbon Capture
Carbon Capture From Air Closer to Commercial Viability
(Score: 2) by Runaway1956 on Wednesday August 22 2018, @02:29PM
Need some clarity, I guess.
Typically, an Interstate Highway was built of concrete. After a few years use, the surface would be "profiled", that is, a big old machine would come along, and grind up the top 1/2 inch or so. A few more years use, and they put a layer of asphalt on top of the already profiled surface. Relatively quickly, the asphalt wears down - two or three years, and it's ready to be replaced. The DOT might pull that old asphalt up, or they might surface over top of it again with more asphalt. Of course, all these years, they are watching the edges of the concrete, watching for erosion, and scanning the roadway with X-rays. Nowadays, they use GPS-like satellite data, so they can see more clearly which slabs might be moving, horizontally or vertically. At SOME POINT, the DOT makes up their mind that the roadbed is no longer serviceable.
They come out, pull up all the asphalt to be recycled, then start breaking up the concrete, and hauling that off to be recycled. Strip the roadbed, reinstall drainage, rebuild the roadbed on top of that, then pour another "superslab".
I leave it to you to find out how long the "typical" slab of concrete lasts. I grew up in Pennsylvania. There was an awful lot of news during my junior and senior high days about fraud. Highways that were expected to last for 20 years and more were being torn up and replaced when I was a teen. (A bit of context - Interstate 80 was being laid down when I was born.)
Now, SOME of those problems were technical. Sharon Pa. was kinda infamous for being near impossible to build across. Apparently, they worked for months to build their stabilized roadbed across the swamp. The bed finally passed inspection, and the crews went home for the night, expecting to start forming the next morning. Problem was - next morning, the roadbed and all the equipment sitting on it had sunk out of sight, into the swamp!
But, there was a helluva lot of fraud involved, as well. Areas further up in the mountains, built on bedrock, were falling apart as well, because the contractors used low-grade mixes, and the inspectors let them get away with it. Profit, profit, profit!!
If the roads are built to the highest standards, you might expect the concrete to last 30 or 40 years. If the standards slip, 20 years is unlikely.
Generally, if you're driving on a major highway in the US, you are probably riding on or above a concrete slab. If you're seeing macadam or some other surface, that surface is just dressing on top of the concrete.
Tertiary roads may or may not have concrete under them. State highway 41, in front of my house, has none. Stabilized earth, pretty good drainage, and about three or four inches of blacktop. When the road needs resurfacing, it gets a chip&tar treatment. Towns and cities pretty much do whatever they want to do, or what their budget allows.
Abortion is the number one killed of children in the United States.