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At what point does it become feasible to just manufacture sand? I know it is possible but how much more expensive must sand get before we just convert quartz mo

At what point does it become feasible to just manufacture sand? I know it is possible but how much more expensive must sand get before we just convert quartz mountains into sand? The article's quoted "50 billion metric tons" of needed sand isn't all that much when compared to the weight of actual mountains.

sliken 3y ago
Quite a bit, it's expensive to turn rocks into sand. Seems plausible that mines will start selling off their sand (after whatever they are mining is removed).
- 14 3y ago
  Is mine sand suitable? The sand used in cement is very specific shape and size. I think that is what makes it so difficult to produce.
  - darth_avocado 3y ago
    It is not. We have an unlimited amount of desert sand available to us, but we need the river sand for construction. Otherwise the likes of Saudi Arabia would be exporting sand instead of importing it for their sky scrapers. The same is true for the mining sand, only a portion of it is appropriate for construction.
    - gtvwill 3y ago
      Actually that's a lie. Desert sand is fine for aggregate. https://www.sciencedirect.com/science/article/abs/pii/S2352710223020235 https://www.sciencedirect.com/science/article/abs/pii/S23527... 41.3mpa on pure desert sand is completely fine. Stronger than your houses slab your probably on now.
      - nerdponx 3y ago
        So why aren't we using it for construction?
        gtvwill 3y ago
        Because existing organisation's would lose their profits from sand mining? Nfi there's plenty of old wives tales from before the time when you could google it and be like "oi gran your talking sh*t" that effect how we do business today. This is probably one of them?
        nerdponx 3y ago
        > Because existing organisation's would lose their profits from sand mining? I'm willing to be cynical and conspiratorial, but this doesn't add up for me. There are so many players between "large construction firms in the USA" and "sand mafia in India" that I find it hard to believe that this is the action of a global cartel. Unless large construction firms in the USA specifically are also run by the sand mafia, which of course is possible, but would be a hell of an exposé if anyone ever caught on.
      - throw0101d 3y ago
        'Just' pressure is not the only metric; from your link: > However, the flexural and tensile strengths tended to decrease as the amount of desert sand increased, particularly beyond a 25% replacement level. So it is not a 1:1 replacement, and there are further considerations that need to be taken into account into how much (if any) desert sand can be put into a particular mix for a particular purpose. Another paper if you want to get into the weeds somewhat: > In this paper, the effect of DSRR, temperature and cooling regime on the mechanical performances of concrete produced with desert sand was analyzed. To study the influence of temperature on the microstructure of concrete produced with desert sand, the microscopic experiments (XRD, SEM) were employed. * https://ijcsm.springeropen.com/articles/10.1186/s40069-020-00402-3 https://ijcsm.springeropen.com/articles/10.1186/s40069-020-0... See also perhaps: * https://engineering.stackexchange.com/questions/18118/why-is-desert-sand-not-processed-to-make-it-suitable-for-concrete https://engineering.stackexchange.com/questions/18118/why-is... It is an area of active research, and perhaps a system will be developed to use it in a cost effective manner.
    - Prickle 3y ago
      We really don't. The majority of desert is not sand. Only around 20% is sand, and around 3% consist of sand dunes. Transportation in deserts is complex due to the rocky terrain that usually fills the rest of the desert. It is economically cheaper and easier to take beach and river sand. (Especially since some countries designate sand dunes as protected areas)
  - Scoundreller 3y ago
    Leftover sand from mineral mining might be better for concrete. As “fresh” sand it’s probably nice and jagged-y, but maybe so fresh without weathering that its weak points haven’t broken off yet.
Reptur 3y ago
Somewhat related, these people are turning glass to sand from recycled bottles. https://www.tv20detroit.com/news/national/turning-recycled-glass-into-sand-could-be-key-to-protecting-coastlines https://www.tv20detroit.com/news/national/turning-recycled-g...
- aaron695 3y ago
  [dead]
coffeebeqn 3y ago
I guess desert sand doesn’t work? That would seem like quite a big supply
- arrosenberg 3y ago
  Desert sand is too smooth and fine for most industrial applications. Most concrete, for example, uses sand and rocks from rivers.
reaperman 3y ago
There are many different types of sand for many different purposes. Sand for silicon is the most expensive. Sands for construction tend to be very cheap. I don't think glass is appropriately pure for silicon - but that would probably be the only application for sand where it could possibly be economical to manufacture rather than extract and process.
opwieurposiu 3y ago
Depending on the type of rocks and how fine you want to grind them, the Specific Energy used is between 10-100(kWh/t). That leads me to guess $8-$25 per ton of electricity used for grinding rocks into sand. I was unable to find good numbers for the capital cost. At an aggregate mine located in Brazil, the total expenses are $80-$160 per ton [1]. The price of sand at home depot is 5.96 for a 50lb bag, $238 per ton. My conclusion is you could make sand by grinding but it would cost 50%-100% more vs. digging up the beach. [1] https://www.scielo.br/j/rem/a/8MW5dFZc5Vh6qMdnTqRKbfM# https://www.scielo.br/j/rem/a/8MW5dFZc5Vh6qMdnTqRKbfM# Edit: Chat GPT thinks it would cost $62.25/per ton make sand from rocks.
- maxglute 3y ago
  Land vs water/barge transport costs for bulk cargo may increase that by magnitude. Article suggest there will be 5x increase in demand and 5x increase in price at current stagnating availability. So that seems maybe doable.
  - Scoundreller 3y ago
    I call shenanigans on the 5x price increase. Marginal increases in commodity price can greatly increase supply as previously uneconomic deposits/production methods suddenly become very viable. And while some processes critically depend on concrete, others will get pushed to other non-concrete methods if price goes up.
    - maxglute 3y ago
      I think this might be case where cheap deposits are obviously geographically constrained. River sand near shores/blue water access for bulk transport to global markets. Once you expand to exploring/exploiting increasingly inland, the logistics of bulk cargo starts stacking up.
      - Scoundreller 3y ago
        Sure, but when you double the acceptable transportation budget/distance, you square the coverage territory. (Assuming an infinite number of routes and no change in cost per distance)

sliken 3y ago

Quite a bit, it's expensive to turn rocks into sand. Seems plausible that mines will start selling off their sand (after whatever they are mining is removed).

14 3y ago
Is mine sand suitable? The sand used in cement is very specific shape and size. I think that is what makes it so difficult to produce.
- darth_avocado 3y ago
  It is not. We have an unlimited amount of desert sand available to us, but we need the river sand for construction. Otherwise the likes of Saudi Arabia would be exporting sand instead of importing it for their sky scrapers. The same is true for the mining sand, only a portion of it is appropriate for construction.
  - gtvwill 3y ago
    Actually that's a lie. Desert sand is fine for aggregate. https://www.sciencedirect.com/science/article/abs/pii/S2352710223020235 https://www.sciencedirect.com/science/article/abs/pii/S23527... 41.3mpa on pure desert sand is completely fine. Stronger than your houses slab your probably on now.
    - nerdponx 3y ago
      So why aren't we using it for construction?
      - gtvwill 3y ago
        Because existing organisation's would lose their profits from sand mining? Nfi there's plenty of old wives tales from before the time when you could google it and be like "oi gran your talking sh*t" that effect how we do business today. This is probably one of them?
        nerdponx 3y ago
        > Because existing organisation's would lose their profits from sand mining? I'm willing to be cynical and conspiratorial, but this doesn't add up for me. There are so many players between "large construction firms in the USA" and "sand mafia in India" that I find it hard to believe that this is the action of a global cartel. Unless large construction firms in the USA specifically are also run by the sand mafia, which of course is possible, but would be a hell of an exposé if anyone ever caught on.
    - throw0101d 3y ago
      'Just' pressure is not the only metric; from your link: > However, the flexural and tensile strengths tended to decrease as the amount of desert sand increased, particularly beyond a 25% replacement level. So it is not a 1:1 replacement, and there are further considerations that need to be taken into account into how much (if any) desert sand can be put into a particular mix for a particular purpose. Another paper if you want to get into the weeds somewhat: > In this paper, the effect of DSRR, temperature and cooling regime on the mechanical performances of concrete produced with desert sand was analyzed. To study the influence of temperature on the microstructure of concrete produced with desert sand, the microscopic experiments (XRD, SEM) were employed. * https://ijcsm.springeropen.com/articles/10.1186/s40069-020-00402-3 https://ijcsm.springeropen.com/articles/10.1186/s40069-020-0... See also perhaps: * https://engineering.stackexchange.com/questions/18118/why-is-desert-sand-not-processed-to-make-it-suitable-for-concrete https://engineering.stackexchange.com/questions/18118/why-is... It is an area of active research, and perhaps a system will be developed to use it in a cost effective manner.
  - Prickle 3y ago
    We really don't. The majority of desert is not sand. Only around 20% is sand, and around 3% consist of sand dunes. Transportation in deserts is complex due to the rocky terrain that usually fills the rest of the desert. It is economically cheaper and easier to take beach and river sand. (Especially since some countries designate sand dunes as protected areas)
- Scoundreller 3y ago
  Leftover sand from mineral mining might be better for concrete. As “fresh” sand it’s probably nice and jagged-y, but maybe so fresh without weathering that its weak points haven’t broken off yet.

Reptur 3y ago

Somewhat related, these people are turning glass to sand from recycled bottles. https://www.tv20detroit.com/news/national/turning-recycled-glass-into-sand-could-be-key-to-protecting-coastlines https://www.tv20detroit.com/news/national/turning-recycled-g...

aaron695 3y ago
[dead]

coffeebeqn 3y ago

I guess desert sand doesn’t work? That would seem like quite a big supply

arrosenberg 3y ago
Desert sand is too smooth and fine for most industrial applications. Most concrete, for example, uses sand and rocks from rivers.

reaperman 3y ago

There are many different types of sand for many different purposes. Sand for silicon is the most expensive. Sands for construction tend to be very cheap. I don't think glass is appropriately pure for silicon - but that would probably be the only application for sand where it could possibly be economical to manufacture rather than extract and process.

opwieurposiu 3y ago

Depending on the type of rocks and how fine you want to grind them, the Specific Energy used is between 10-100(kWh/t). That leads me to guess $8-$25 per ton of electricity used for grinding rocks into sand. I was unable to find good numbers for the capital cost. At an aggregate mine located in Brazil, the total expenses are $80-$160 per ton [1]. The price of sand at home depot is 5.96 for a 50lb bag, $238 per ton. My conclusion is you could make sand by grinding but it would cost 50%-100% more vs. digging up the beach. [1] https://www.scielo.br/j/rem/a/8MW5dFZc5Vh6qMdnTqRKbfM# https://www.scielo.br/j/rem/a/8MW5dFZc5Vh6qMdnTqRKbfM# Edit: Chat GPT thinks it would cost $62.25/per ton make sand from rocks.

maxglute 3y ago
Land vs water/barge transport costs for bulk cargo may increase that by magnitude. Article suggest there will be 5x increase in demand and 5x increase in price at current stagnating availability. So that seems maybe doable.
- Scoundreller 3y ago
  I call shenanigans on the 5x price increase. Marginal increases in commodity price can greatly increase supply as previously uneconomic deposits/production methods suddenly become very viable. And while some processes critically depend on concrete, others will get pushed to other non-concrete methods if price goes up.
  - maxglute 3y ago
    I think this might be case where cheap deposits are obviously geographically constrained. River sand near shores/blue water access for bulk transport to global markets. Once you expand to exploring/exploiting increasingly inland, the logistics of bulk cargo starts stacking up.
    - Scoundreller 3y ago
      Sure, but when you double the acceptable transportation budget/distance, you square the coverage territory. (Assuming an infinite number of routes and no change in cost per distance)