Sand, this kind of thing is not lacking on earth, especially the sand in the desert, which is not only abundant, but also useless.


Sand is an indispensable building material. Sand is indispensable in building cement and paving asphalt, but the sand mentioned here does not include the sand in the desert. After years of weathering, the sand in the desert has a very smooth surface and can not be used as raw materials for building materials. It's a pity. Looking at the world, the Sahara desert, the Arabian desert and the Libyan Desert together cover an area of more than 10 million square kilometers, and the Taklimakan Desert in China has a full 330000 square kilometers. If there is more sand, is it really useless? What is sand? The main component of sand is silicon dioxide. Is there anything that is also silicon dioxide? Yes, glass.


Glass is silica, and sand is also silica. Moreover, compared with the sand in other places, the sand in the desert contains less impurities. Can these sand be turned into glass after heating?

This seems to be a good idea. It's fun to think about it. If you turn the sand in the desert into glass, you can not only improve the earth's ecology, but also provide mankind with glass that can never be used up. Wouldn't you kill two birds with one stone? The interesting thing about this world is that as long as you can think of something, someone must have put it into practice. Abroad, some young people went to the desert to heat the sand and try to make glass. The whole experimental process was later published on foreign websites.


In the experiment, after heating the sand to 2200 degrees Celsius, it does show the feeling of crystal clear glass, but it is still a certain distance from the glass known in our common sense.

So why can't the same silicon dioxide become the familiar glass after the sand is heated? The key lies in the different heating temperatures, and the reason for the different heating temperatures is the different raw materials. Indeed, the main raw material for making glass is silica, but not only silica. In addition to the main raw materials, many auxiliary materials should be added, such as boric acid, borax and limestone. In addition to adding auxiliary materials, impurities must also be removed, and "iron removal" is a very important link in the glass manufacturing process. Without this link, qualified glass cannot be produced.


When everything is ready, it is fired. The glass is usually fired in a tank kiln or crucible kiln. Under the condition of ensuring uniform heating, it only needs a temperature of about 1500 degrees Celsius to obtain qualified liquid glass. Finally, it only needs to place these liquid glass in the mold for shaping, and we can obtain the glass products we want.


So what if we don't add these auxiliary materials and remove impurities, and directly take the sand from the desert and burn it? Like the experiments done by those young people abroad, it takes about 2200 degrees Celsius to turn sand into a smooth and transparent liquid. Too high temperature will lead to changes in the structure of the material. The main component of sand is silicon dioxide, in which silicon atoms and oxygen atoms are connected by covalent bonds.


Too high temperature will cause the covalent bond between silicon atom and oxygen atom to break, resulting in the free state and random combination of atoms. Although this change is only a physical change, it is enough to make it unable to form the look of glass we expect.


It can be seen that it is a bit whimsical to use the sand in the desert to directly burn glass. If so, it is too simple to control desertification. So since you can't directly use sand to burn glass, can you purify the sand in the desert and reuse it? This is still quite difficult. Yes, the sand in the desert has relatively few impurities, and its main component is silica, but it is not easy to separate these silica. In the face of these small round sand particles that can be seen under the microscope, how can we separate them?


The physical separation methods usually used are difficult to screen the silica particles in the sand. Even if there are methods, the cost is quite high.

Instead of separating silica particles from sand, it is more convenient and cheaper to extract silica from stone. Moreover, silica is not a scarce resource, and its reserves on the earth are very huge, so it can't be close to sand at all. It can be seen that the sand in the desert is still useless. Although the idea of burning glass with sand can not come true, this idea is still worthy of affirmation. The most effective way of environmental governance is to find some use for what you want to eliminate. The governance method of unilateral payment is often difficult to last long.