
Demand for sand is killing rivers in Africa - Red_Tarsius
http://www.bbc.com/news/magazine-41123284
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payne92
Demand for sand (for concrete) is killing rivers... _in Africa_

In the US, dredging rivers or land near a waterway is pretty restricted. Sand
is typically mined from open pits, see:
[https://en.wikipedia.org/wiki/Sand_mining#United_States](https://en.wikipedia.org/wiki/Sand_mining#United_States)

~~~
tryingagainbro
Isn't the river sand full of mud, in many cases? Can it really be washed that
well?

~~~
jaclaz
Not only it can be washed perfectly but river sand (and gravel) tend to be
much better for concrete when compared to "crushed" aggregates.

More or less the reason is that usually for a given size river ones are
harder/more resistant, and have rounded edges (which also imply a bigger
resistance) due to the cycles (wear, long time immersion, etc.) they were
subjected to in the river.

And, as a final advantage, concrete made with rounded aggregates is usually
easier to pump.

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iosDrone
The New Yorker wrote a much better article about this months ago:
[https://www.newyorker.com/magazine/2017/05/29/the-world-
is-r...](https://www.newyorker.com/magazine/2017/05/29/the-world-is-running-
out-of-sand)

~~~
martinpw
Also an article here on impact of sand mining on rivers in India:

[https://www.nytimes.com/2017/03/01/magazine/sand-mining-
indi...](https://www.nytimes.com/2017/03/01/magazine/sand-mining-india-how-to-
steal-a-river.html)

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kakwa_
For the French or German speakers here, there is an interesting 2013 Arte
documentary on the subject:

French: [https://www.arte.tv/fr/videos/046598-000-A/le-sable-
enquete-...](https://www.arte.tv/fr/videos/046598-000-A/le-sable-enquete-sur-
une-disparition/)

German: [https://www.arte.tv/de/videos/046598-000-A/sand-die-neue-
umw...](https://www.arte.tv/de/videos/046598-000-A/sand-die-neue-
umweltzeitbombe/)

(I didn't find an English version or English subtitles for it, sorry...)

It's available until September 18.

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stevenwoo
Industrial scale mining often has unintended consequences - there was a long
running sand operation in California that caused erosion all around it on the
coast unless you asked the company that was doing it.
[http://www.mercurynews.com/2017/06/27/controversial-
beachfro...](http://www.mercurynews.com/2017/06/27/controversial-beachfront-
sand-mining-operation-along-monterey-bay-to-close/)

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apthnz
Is there an alternative to using riverbed sand in concrete? Or an alternative
to concrete for big buildings?

~~~
Animats
Crushing rocks down to sand is common. Here's the machinery.[1] The trick is
to bang the rocks together. China seems to be making lots of sand for
concrete. There are many manufacturers in China making rock crushers and sand-
making machines.[2] China has plenty of mountain rock suitable for rock
crushing.

Here's a marketing paper on making sand, and what to make for making
concrete.[3]

[1]
[https://www.youtube.com/watch?v=1CpjRMICXNM](https://www.youtube.com/watch?v=1CpjRMICXNM)
[2] [https://www.alibaba.com/showroom/vsi-
crusher.html](https://www.alibaba.com/showroom/vsi-crusher.html) [3]
[http://www.metso.com/showroom/construction/new-type-of-
crush...](http://www.metso.com/showroom/construction/new-type-of-crushed-sand-
to-replace-natural-sand-in-concrete-production/)

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bhhaskin
It is really crazy how much sand is needed for modern development. It is a key
component in a ton of different things.

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csense
Given that silicon's the second most abundant element on Earth, it seems like
it should be trivial to mine without causing environmental damage.

~~~
s0rce
Most of the sand is mined to make concrete (cement + sand + rocks + water =
concrete). I think they use much smaller amounts of much higher purity sand
for making silicon.

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zip1234
What about the Sahara desert? Seems like Africa has plenty of sand--why are
they taking it out of rivers? Expensive to transport?

~~~
pasta
A lot of desert sand can be compared to powder. So in most cases this cannot
be used.

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EGreg
Here's an idea - why not require the companies to replace the river sand with
desert sand after mining it? Have they tried to use desert sand in the river?

~~~
zo1
This is Africa you're talking about. As much as that sounds like noble and a
good idea, convincing local communities and especially businesses here is not
going to happen unfortunately.

It's a consequence of being in the third world and having a "catch up at all
costs" mentality. Besides, conservation and environmentalism just isn't as in-
grained in most African cultures as it is in the west.

Even if you convinced the local government of putting such a law on the books,
the odds of them being able to track and enforce such a law is next to
impossible. Maybe in more developed countries like South Africa or Namibia,
but not in most of the others.

~~~
EGreg
Well why not have whoever is concerned about this sand thing fund an operation
to go and bring sahara sand and dump it all along the riverbed? And the
operation would be funded by local taxes on the companies extracting the
resources. Solved.

Unless you're saying these governments have no negotiating power about their
own land and resources? In which case this is just straight-up PLUNDER.

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anotherbrownguy
Oh so Africa is building long lasting concrete buildings and making life
easier for everyone... something that most of the western world and a huge
part of the developing world has already been using for a long time in the
same way? No, let us tell you something much more important: how the freaking
rivers are "dying".

Environmentalism is anti-humanism.

~~~
hobs
Did you read the article?

They are discussing offshoring this sand to other countries that can afford
it, not to build useful African structures. An argument from "The world has
already been using this for a long time" could be used for any number of
grotesque and terrible acts (and has) so I will ignore that part.

The main complaint about the "rivers dying" is that it has a outsized impact
on the poor who use those rivers for food and water (which is no longer
available and which is no longer captured, respectively.)

While some people truly believe in the preservation of nature over humans,
most of us "Environmentalists" want to save the environment because of the
direct and indirect human suffering inappropriate exploitation of our shared
resources cause.

~~~
Spooky23
Theres a lot of domestic construction going on in African countries. That
growth is all using modern methods, which means lots and lots of pumped
concrete.

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zghst
Oh look, the 21st century looting of Africa for its resources. Just to think
so many materials extracted from the continent and now sand.

This poor continent keeps getting jacked.

~~~
averagewall
It's being used for local construction. Even if it wasn't, do you have the
same sympathy for Australia which is a major source of many minerals?
Continents aren't people. They don't have property rights. People do, and it's
important for people to be able to exercise those rights to benefit their own
lives.

