Sand

Are we really running out of it?

The problem lies in the type of sand we are using. Desert sand is largely useless to us. The overwhelming bulk of the sand we harvest goes to make concrete, and for that purpose, desert sand grains are the wrong shape. Eroded by wind rather than water, they are too smooth and rounded to lock together to form stable concrete.

We cannot extract 50 billion tonnes per year of any material without leading to massive impacts on the planet and thus on people’s lives – Pascal Peduzzi The sand we need is the more angular stuff found in the beds, banks, and floodplains of rivers, as well as in lakes and on the seashore. The demand for that material is so intense that around the world, riverbeds and beaches are being stripped bare, and farmlands and forests torn up to get at the precious grains. And in a growing number of countries, criminal gangs have moved in to the trade, spawning an often lethal black market in sand.

Ironically, as we discussed at the Space Settlement Summit last week, lunar regolith dust has ideal properties in that regard, which is why it’s such nasty stuff to deal with. Probably not worth the cost of importing it to earth, though.

[Update a while later]

For some reason, this reminds me of the old joke about what would happen if socialists took over the Sahara Desert.

18 thoughts on “Sand”

  1. The mass of the Earth’s crust is about 2.4E19 tonnes, at least 10% of which is silica (sand). At a rate of use of 50E9 tonnes per year, we can damn well use all we want for the next 48 million years.

  2. So desert, wind-worn, sand is too spherical?

    Can our industries not develop “crushers” that shatter the spheres into smaller jagged shards?

    1. A year or so ago some idiot scientists said we could run out of nitrogen because we keep sucking it out of the atmosphere to make fertilizer. In a couple of million years that might indeed be a problem.

  3. The most valuable thing about sand and other aggregate, to be pedantic, is its location. This is because, oddly enough, how cheap it is at the pit. Usually a few dollars a ton. It’s very common for the trucking cost to double that. That means that a pit close to a major project is much more valuable than one even a few miles further.

    Good aggregate can allow a given strength to be developed with somewhat less cement, which is by far the most costly part of the mix. So there are some trade offs to be made.

    By the way, manufactured sand is a thing, it’s both expensive and hell on equipment but makes very good concrete. For fracking, you want the smooth rounded sand so it will flow into the fissures in the formation. I remember when we were running out of it too.

    Also note that the examples all seem to be in places with serious corruption. When the BBC announces yet another coming crisis, I pretty much assume it’s B.S.

    1. When the BBC announces yet another coming crisis, I pretty much assume it’s B.S.

      Well, I certainly give credit to the BBC for providing the foundation for much that was Pythonesque…

      Ladies and Gentlemen you are listening to the BBC. Before we begin our usual program denigrating the corruption in the developing world, let’s take a short break for something completely false.

  4. Yet another reason why Michigan might eventually become the most valuable real estate on the planet. Between the L. Michigan shore sand dunes and direct access to 4 of the Great Lakes, they’ve got it made. Well, at least until the end of this interglacial, when the state will again be covered by a couple of miles of ice.

    Seriously, the comment about location for aggregate is correct. It has to be close to be useful, so the whole premise of the article is a bit silly. People are quarrying near rivers because people live near rivers. Any aggregate more that a few dozen miles away from a construction site is useless.

  5. Let’s see, we’ll need a backhoe, some headlight-shaped steel cannisters with steel mesh parachutes, a big skip loader and a magnetic induction catapult on the Moon…

    Moonsand, Inc.: So where would you like that hundred tons of sand?

    Customer: Next to my project site in Minas Gerais, Brazil (os Confederados are an industrious folk).

    M: Loads cannister with sand and fires it on the correct trajectory. Cannister reenters (using cold sand as heat-sink), pops chute, and thumps down 500 meters from work site.

    C: Obrigado!

    M: You can return the empty canister for a deposit refund. Let us know when you need more.

    And as a side benefit, you can just drop sand on the heads of anyone you don’t like… Hm. Where have I heard that before? Something about throwing rice…

    1. I had a similar thought. Moon Pilings Inc. No need to waste time drilling and using a pile driver. We can pack up a pre-formed lunar concrete piling with special retry coatings and drop insert them on your site overnight! Call Manny at MYCROFT-1-2000.

Leave a Reply

Your email address will not be published. Required fields are marked *