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The problem seems to be that desert sand is too smooth to use in concrete. Perhaps a method is needed for fusing desert sand in such a way that it becomes rough. Perhaps large fresnel lenses that use sunlight to fuse the grains into small clumps?
So, industry needs angular sand, and that’s mostly found on rivers. The difference matters for concrete and such, but I wonder whether rivers are so fussy about the type of sand in them. What would happen if you took the desert sand and used it to replace the river sand? Because you’re now mining and transporting twice, you’ll definitely have higher costs.
They might be. You might find that smoother sand flows more easily, and may be washed away. Certainly the size of grain is important, as smaller grains are carried more easily by the water.
If the intention is simply to displace water, then a better option may be larger rocks. These would eventually be worn down to make more angular sand.
This seems to be "BioPhysical Economics and Resource Quality", which is a Springer publication. Here's the actual article, "A Simple System Dynamics Model for the Global Production Rate of Sand, Gravel, Crushed Rock and Stone, Market Prices and Long-Term Supply Embedded into the WORLD6 Model", by Harald U. Sverdrup and others.[1] It's not even paywalled. Some quotes:
"The resources of sand and gravel are estimated at 12 trillion ton each, another 125 trillion tons of rock is suitable for crushing to sand and gravel and at least 42 trillion ton of quality stone is available for production of cut stone."
"Sand, gravel and stone materials use in construction amounts to about 47–59 billion tons per year"
"Sand and gravel show plateau behaviour and reach their maximum production rate in 2060–2070. The reason for the slight peak towards a plateau behaviour is partly driven by an expected population decline and increasing prices for sand and gravel, limiting demand. Assuming business-as-usual conditions rates remain at that level for centuries."
So we have another 1000-2000 years of sand left? Did anyone read the references?
Incidentally, if you are in Silicon Valley and need base rock, there's a place on Seaport Boulevard in Redwood City where you can get free concrete, ground into gravel-sized chunks. They charge for concrete disposal; the product is free.
[1] https://link.springer.com/article/10.1007/s41247-017-0023-2
The problem seems to be that desert sand is too smooth to use in concrete. Perhaps a method is needed for fusing desert sand in such a way that it becomes rough. Perhaps large fresnel lenses that use sunlight to fuse the grains into small clumps?
I had a similar thought, although I think fusing wouldn't solve the problem, as it wouldn't create a rough surface. That said, fusing might make it easier to fracture the sand and make rough surfaces.
So I've come around to the belief that we're on the verge of another massive civilization-level change that will be transformative. Think flight, electricity, motorized transport, plastic, writing, agriculture, domestication, firearms, etc (and no I'm not just listing techs from Civ). That change will be when we have cheaper mass power generation than fossil fuels. The reason this will be transformative is that a lot…
It would seem to me that we simply need to make buildings (and other materials) out of other resources. Whether they are expensive or only effective in certain situations is for the purchaser to decide. One man's bamboo is another man's carbon fiber, I suoppose.
Wouldn't it be handy if you could make granules of "sand" out of carbon, perhaps captured from the air...
Earlier quoted context omitted.
Wouldn't it be handy if you could make granules of "sand" out of carbon, perhaps captured from the air...
It's even better than that. You can grind metal oxides that form a sizeable fraction of Earth's crust and are relatively easy to extract into a sort of "dust" or "sand" that will actively sequester carbon out of the air, with no further energy input needed. Not silicon-based rock, though,
The problem seems to be that desert sand is too smooth to use in concrete. Perhaps a method is needed for fusing desert sand in such a way that it becomes rough. Perhaps large fresnel lenses that use sunlight to fuse the grains into small clumps?
As with every resource-depletion issue like this, the obvious answer is to reduce the number of humans. Consider never reproducing instead of trying to think of some clever technological solution.
So, industry needs angular sand, and that’s mostly found on rivers. The difference matters for concrete and such, but I wonder whether rivers are so fussy about the type of sand in them. What would happen if you took the desert sand and used it to replace the river sand? Because you’re now mining and transporting twice, you’ll definitely have higher costs.