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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 Monday August 20 2018, @04:40PM (2 children)
That's all well and good: Portland cement and it's concrete have a lot of variations. I've poured with added air, with fiberglass, with fly ash, with oversize rock, with pea gravel. I can't say just how much the recipe for Portland varies, but I can say with certainty that not every bag of Portland I've ever handled was precisely the same.
The thing about Roman cement is, at least some of it has lasted 2000 years. THAT is what we need! And, the secret seems to be in the volcanic ash they used. Our fly ash is a poor substitute for the volcanic ash they used.
(Score: 0) by Anonymous Coward on Monday August 20 2018, @11:56PM
https://www.geopolymer.org/archaeology/roman-cement/high-performance-roman-cement-and-concrete-high-durable-buildings/ [geopolymer.org]
(Score: 2) by deimtee on Tuesday August 21 2018, @11:31AM
Other than the fly ash, the big differences are water content when molding, and time to set. Roman concrete is barely damp, and is pounded into place - add some, tamp it down hard, add a bit more, tamp it down hard, etc. Then leave it alone.
It takes weeks to set to the point of being slightly usable, and months to years to set properly.
The water used to set modern concrete leaves voids, which is why it deteriorates so fast. Water and air can percolate through to the rebar, causing rust, and water in the voids can freeze, causing spalling.
If you cough while drinking cheap red wine it really cleans out your sinuses.