4 ms·

What's stopping us from making new sand with a giant solar powered grinder? We should have plenty of rocks...

pjc50 9y ago
"Running out of" should, as always, come with the qualifier "at a reasonable price". Rock-crushing is quite energy intensive compared to just dredging. Generally in the West you'll find substitutes like crushed concrete or pulverised fly ash being added to the mix (although PFA itself will be in short supply as it's a coal-fired power station by product)
- ggcdn 9y ago
  IIRC, in structural concretes flyash is used as an admixture to reduce portland cement usage, and enhance some properties like permeability, but not as a replacement for sand.
- sliverstorm 9y ago
  And/or the qualifier "we are now causing a lot of damage getting resource X because our preferred source is running dry". Rivers can afford to lose some sand, but not all. Convenient oil Wells cause very little damage compared to clear-cutting and surface mining tar sand.
mrob 9y ago
Crushing rocks to sand already happens. Animats posted some interesting links the last time sand shortages were discussed here: https://news.ycombinator.com/item?id=15208432 https://news.ycombinator.com/item?id=15208432
ska 9y ago
"running out of sand" parallels "running out of oil". It's not that there isn't any left, it's just not cost effective.
rm_-rf_slash 9y ago
There are different kinds of sands, and the better kinds are more desired and presumably more expensive to manufacture. Sarasota has sand that feels like a fine powder. It’s wonderful, and also quite limited. In fact there was a recent expensive reconstruction of a beach that was blown away quite quickly because the city didn’t believe the engineers saying it needed more support. Millions of dollars of prime sand lost. Cape Cod has sand that feels like rocks (and the water is ALWAYS cold, even in July!). Nobody would buy that.

"Running out of" should, as always, come with the qualifier "at a reasonable price". Rock-crushing is quite energy intensive compared to just dredging. Generally in the West you'll find substitutes like crushed concrete or pulverised fly ash being added to the mix (although PFA itself will be in short supply as it's a coal-fired power station by product)

ggcdn 9y ago
IIRC, in structural concretes flyash is used as an admixture to reduce portland cement usage, and enhance some properties like permeability, but not as a replacement for sand.
sliverstorm 9y ago
And/or the qualifier "we are now causing a lot of damage getting resource X because our preferred source is running dry". Rivers can afford to lose some sand, but not all. Convenient oil Wells cause very little damage compared to clear-cutting and surface mining tar sand.

mrob 9y ago

Crushing rocks to sand already happens. Animats posted some interesting links the last time sand shortages were discussed here: https://news.ycombinator.com/item?id=15208432 https://news.ycombinator.com/item?id=15208432

ska 9y ago

"running out of sand" parallels "running out of oil". It's not that there isn't any left, it's just not cost effective.

rm_-rf_slash 9y ago

There are different kinds of sands, and the better kinds are more desired and presumably more expensive to manufacture. Sarasota has sand that feels like a fine powder. It’s wonderful, and also quite limited. In fact there was a recent expensive reconstruction of a beach that was blown away quite quickly because the city didn’t believe the engineers saying it needed more support. Millions of dollars of prime sand lost. Cape Cod has sand that feels like rocks (and the water is ALWAYS cold, even in July!). Nobody would buy that.