Why 'sand shortage' is a major problem for the world?
Even if you go to the sea or go to the mountains you will see "sand" you see as common, but in reality worldwide "sand shortage" is a problem. Why is sand shortage a problem, The Verge of international news media is publishing a commentary movie on YouTube.
Why sand scarcity is about more than "running out" of sand - The Verge
A microscopic look at why the world is running out of sand - YouTube
Even saying "sand" in one word, the sand has incredible diversity that reflects the characteristics of the place.
Men who head to the beach ......
Collected sand from the sandy beach.
In order to observe the sand with a microscope, we send samples to New York.
The reason why we have to do such things is because sand which seems to be common is actually a very important resource worldwide.
Except water, the most used material by humans is concrete. Sand becomes the material of this concrete.
Construction rush has occurred in India, China, parts of the USA, etc., and the demand for concrete is getting bigger and bigger.
That appeared in that was Mr. William Poa , Science Producer of The Verge . "The definition of sand is broad, sand is made from various stones and minerals, it is distinguished from its size, not its type"
"SILT" is 0.05 mm or less, what is called "GRAIN OF SAND" is 0.05 mm to 2 mm, and "GRAVEL" is 2 mm or more. However, it is equally important not only the size but also where the sand came from, what shape it is made from, and what it is made of.
Basically concrete is made by mixing sand and big stone with water and cement .
And it is "river sand" that is said to be most suitable for concrete.
The grains of river sand have rounded corners and are consistent in size, so it is easy to integrate cement and sand. Also, hard minerals such as quartz are the center, and soft minerals are not mixed much.
Frank Leith of the sand manufacturing company " Vulcan Materials " says that "river sand is originally on the mountain" for this reason.
For example, the sand in the Sacramento River in California, USA is coming from the Klamath Mountains, 400 miles away (about 640 km).
Those mountains scraped by rain and wind etc. flow into the river ......
Stones and minerals collide with each other in the flow of the river, and they scrape each other. Among them, round corner sand is born. At this time, soft minerals are decomposed and only hard mineral sand reaches the Sacramento River.
Because rivers are connected to the ocean, river sand also reaches the ocean.
However, since salt is attached to the sand on the beach, the chemical reaction when making concrete is different from pure sand. Also, it is cited as a disadvantage that seashells and marine organisms are included. Of course you can remove them, but it will require complicated work and the final concrete price will be high.
From these problems, 'population sand' is also made, but the population sand is difficult to handle. Because it does not go through a number of processes by nature, the corner is sharp and pointy.
Poa with a sample of artificial sand.
This is artificial sand.
Although river sand and artificial sand are very different, both have a problem of heavy and bulky to transport. The cost of transporting artificial sand will take 2 to 4 times as much as manufacturing cost.
Therefore, it seems that sand often erases local production areas. This is because when the distance is too long, the advantage of using relatively inexpensive artificial sand disappears.
The problem of sand "can not be transported far" is a very big problem. Because concrete can not be used in places where concrete is required.
For this reason, there are "sand mafia" stealing sand in India ... ...
In Dubai surrounded by the desert and without river sand, we rely on sand imported from Australia.
"To do the right job, you need to have the right sand in the right place," Pua said.
in Video, Posted by darkhorse_log