China builds with manufactured sand, easing worry about overmining and environmental cost
- Artificial sand is produced by crushing and sieving rock or mine tailings, a process that offers an alternative for the construction industry
About 80 per cent of the sand used in China’s construction industry today is manufactured, marking a turning point in engineering, and offering hope to solve a major crisis for the world, according to a new study.
Sand has been used in buildings for at least 60,000 years. It is the second most used resource on Earth after water. Rapid population growth and urbanisation in recent decades have accelerated the depletion of natural sand reserves.
The United Nations Environment Programme (UNEP) estimates that 50 billion tonnes of sand and gravel – stones larger than sand – is extracted for construction every year, enough to build a wall 27 metres (88 feet) wide and 27 metres high around the planet.
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Crushing rocks into sand: rising costs push China to manufacture artificial components for cement
China – where the urbanisation rate has soared from 17 per cent to 58 per cent over the past four decades – is particularly hungry for sand. The UNEP warned that the world might soon run out of sand resources because of the huge demand from China and other rapidly developing countries.
“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,” UNEP researcher Pascal Peduzzi told the BBC in 2019.
However, according to a study published in the journal Nature Geoscience last month, China’s overall sand supply – which increased by about five times between 1995 and 2020 – comes mostly from artificial sand, which is produced by mechanically crushing and sieving rock or mine tailings.
The study was a collaboration between international researchers from institutes that include the Research Centre for Eco-Environmental Sciences under the Chinese Academy of Sciences, Leiden University in the Netherlands and the University of Cambridge in Britain.
The team built a dynamic monitoring system, known as “material flow analysis”, and found that China’s sand supply patterns “fundamentally shifted”.
