The sand in the desert is ready-made, there is no need to dig like river sand or sea sand, it just needs to be moved, but why don’t we use those huge amounts of sand?
Sand and gravel are the most extracted substances, even exceeding fossil fuels. Urbanization and global population growth are driving demand surges, especially in China, India and Africa.
Approximately 32 to 50 billion tons of sand and gravel are used worldwide each year, mainly for the manufacture of concrete, glass and electronics. This exceeds the rate of natural recovery, and demand may exceed supply by the middle of this century.
Lack of knowledge and supervision makes this unsustainable mining situation even worse. Although a considerable part of the world is covered by a desert, for example, China ’s desert area is about 700,000 square kilometers, which are mainly distributed in the northwest of China. So why don’t we take advantage of those huge amounts of sand?
The sand in the desert is ready-made, there is no need to dig like river sand or sea sand, it just needs to be moved. However, in reality, every construction team generally does not choose ready-made sand in the desert, but chooses river sand and sea sand to build buildings. Here are some reasons.
First of all, the sand in the desert is relatively severe due to the weathering in the desert area, and the sand particles are relatively small. To the standard of building sand, the river sand and sea sand particles used in the building are relatively large and uniform, which can form a relatively strong concrete. Therefore, desert sand cannot be used casually. Once casually used, it is likely to cause a construction accident.
Secondly, the sand in the desert is not as hard as river sand. After all, the main components of river sand are quartz and silica. These components have a certain hardness and can be mixed well to form concrete. Therefore, the concrete formed by river sand is relatively strong, but the desert sand The hardness is small, and the formed concrete is relatively fragile, which is not conducive to the formation of strong concrete, so it is not suitable for building construction.
Finally, in addition to the characteristics of the sand, the cost of moving the sand may cost a lot. excavation and transportation of sand will cost. Even if the sand in the desert meets the standards of the building, it is necessary to consider the distance to transport sand from the desert area. As we all know, due to climate problems in the desert, the cost of constructing and maintaining roads is relatively large, and roads are rarely built. Therefore, the process of transporting desert sand requires a lot of transportation costs and has to deal with various desert climate problems. Sand is generally in places where roads are relatively developed, and the transportation cost required is relatively low.
In conclusion, the particles and hardness of the desert sand cannot meet the requirements for construction sand, the possibility of using desert sand has been ruled out to a certain extent, plus the transportation cost of desert sand is relatively high. Therefore, construction teams generally do not use ready-made sand in the desert, but use excavation to treat river sand and sea sand to meet construction sand.
In fact, sand can not be put into use directly. Even the sea sand or beach sand usually used by the construction team has to be treated before they can be used in construction. Otherwise, Salt can corrode buildings. It can be seen that sea sand is not as simple to handle as river sand and can’t be used directly. After all, it involves building safety issues, any raw materials used meet their certain standard.
So, we know that the sand particles in the desert are too smooth to be used, and most of the angular sand particles suitable for industrial production come from rivers, that is less than 1% of the world’s land area.
This gravel extraction has a profound impact on ecology, infrastructure and the livelihoods of 3 billion people living along river banks. For example, sand mining may reduce groundwater levels, increase the difficulty of pumping drinking water, accelerate river bed scouring, and damage bridges and dikes.
Most of the sand trade is illegal. For example, between 2006 and 2016, Singapore reported less than 4% of 80 million tons of sediment imported from Cambodia was identified as export by the latter. Illegal sand mining is common in about 70 countries. Hundreds of people, including local citizens, police and government officials, have reportedly been killed in battles over sand and soil in countries including India and Kenya over the past 10 years.
Reports from the wildlife charity World Wide Fund for Nature (WWF) and the United Nations Environment Programme (UNEP) highlight all of these issues and question the sustainability of sand mining. The root cause is too little data and a lack of policies to support responsible consumption and extraction.
There is now an appeal to UNEP and the World Trade Organization (WTO) to establish and oversee a global programme for monitoring sand resources. Researchers need to establish accounting procedures for sand flowing into and out of rivers-legal and illegal.
They need to make their peers, the public and policymakers aware of the seriousness of the problem. In this regard, some people have suggested why not move ready-made sand in the desert? This can reduce a lot of salvage and processing costs.