3 ms·

Is it possible to just figure out the ratio of rocks and put them into a grinding machine to make custom sand?

xattt 29d ago
Zombocom… the only limit is your imagination. In all seriousness, rock crushing is energy intensive relative to just taking sand from the source.
- alexpotato 29d ago
  Create a bag of rocks and leave them in an area with lots of waves. Let nature and physics do the rest.
  - darth_avocado 29d ago
    In a few million years
  - qwerpy 29d ago
    Pretty sure this is a joke but you never quite know, given that HN is infamous for these "javascript programmer applies his smarts to something that's not javascript" moments.
    - MisterTea 29d ago
      "bag of rocks" is so ridiculous that I would call it a joke for sure.
  - deleted 29d ago
    [deleted]
Tyr42 29d ago
You'd also care about angular sand vs round sand grains.
- lostlogin 29d ago
  This is the difference and why smashing up rocks doesn’t get the same result. Round sand is nicer. You can probably engineer the sand somehow but it’s going to be costly.
  - slashdev 29d ago
    I thought it was the other way around. Too fine/round is not good for concrete, which is why desert sand is unsuitable.
    - AngryData 29d ago
      Yes, if you want a good stable foundation for any structural base you want your medium to be sharp and irregular so it locks together. Round material, be it sand or rocks, can be pushed around more like a liquid. Sharp and irregular get tangled together and acts more like one solid object.
    - Exoristos 29d ago
      GP is probably talking about beach sand.
philipkglass 29d ago
Yes: "Crushed rock sand – An economical and ecological alternative to natural sand to optimize concrete mix" https://www.sciencedirect.com/science/article/pii/S2213020916300921 https://www.sciencedirect.com/science/article/pii/S221302091... The main problem is that even though crushing rocks is affordable, illegal sand mining is even cheaper in regions where law enforcement is weak.
liveoneggs 29d ago
it would be better to farm coral reefs and parrot fish
darth_avocado 29d ago
You’re talking about a product that’s quite literally “pick it up and sell it”. Adding a single step to the process will be economically more expensive. Mining, logging, fishing etc. are all similar examples.
- lazide 28d ago
  It isn’t quite pick it up and sell it (just like most mining) - a lot of work goes into finding and consistently identifying the correct grade.

xattt 29d ago

Zombocom… the only limit is your imagination. In all seriousness, rock crushing is energy intensive relative to just taking sand from the source.

alexpotato 29d ago
Create a bag of rocks and leave them in an area with lots of waves. Let nature and physics do the rest.
- darth_avocado 29d ago
  In a few million years
- qwerpy 29d ago
  Pretty sure this is a joke but you never quite know, given that HN is infamous for these "javascript programmer applies his smarts to something that's not javascript" moments.
  - MisterTea 29d ago
    "bag of rocks" is so ridiculous that I would call it a joke for sure.
- deleted 29d ago
  [deleted]

Tyr42 29d ago

You'd also care about angular sand vs round sand grains.

lostlogin 29d ago
This is the difference and why smashing up rocks doesn’t get the same result. Round sand is nicer. You can probably engineer the sand somehow but it’s going to be costly.
- slashdev 29d ago
  I thought it was the other way around. Too fine/round is not good for concrete, which is why desert sand is unsuitable.
  - AngryData 29d ago
    Yes, if you want a good stable foundation for any structural base you want your medium to be sharp and irregular so it locks together. Round material, be it sand or rocks, can be pushed around more like a liquid. Sharp and irregular get tangled together and acts more like one solid object.
  - Exoristos 29d ago
    GP is probably talking about beach sand.

philipkglass 29d ago

Yes: "Crushed rock sand – An economical and ecological alternative to natural sand to optimize concrete mix" https://www.sciencedirect.com/science/article/pii/S2213020916300921 https://www.sciencedirect.com/science/article/pii/S221302091... The main problem is that even though crushing rocks is affordable, illegal sand mining is even cheaper in regions where law enforcement is weak.

liveoneggs 29d ago

it would be better to farm coral reefs and parrot fish

darth_avocado 29d ago

You’re talking about a product that’s quite literally “pick it up and sell it”. Adding a single step to the process will be economically more expensive. Mining, logging, fishing etc. are all similar examples.

lazide 28d ago
It isn’t quite pick it up and sell it (just like most mining) - a lot of work goes into finding and consistently identifying the correct grade.