Monday, April 28, 2014

State of Sand, 2014

From the Conversable Economist:

Demand for Sand

These are boom times for the sand industry, which is actually a mixed blessing, resulting in high prices and even environmental risks. The Global Environmental Alert Service of the United Nations Environment Programme tells some of the story in a March 2014 report, "Sand, rarer than one thinks." As the report notes (citations omitted for readability): "Globally, between 47 and 59 billion tonnes of material is mined every year, of which  sand and gravel, hereafter known as aggregates, account for both the largest share (from 68% to 85%) and the fastest extraction increase ..."

To get a sense of the volume here,  consider this comparison: "A conservative estimate for the world consumption of aggregates exceeds 40 billion tonnes a year. This is twice the yearly amount of sediment carried by all of the rivers of the world, making humankind the largest of the planet’s transforming agent with respect to aggregates ..." Or to look at it another way, one major use of aggregates like sand and gravel is for concrete. "Thus, the world’s use of aggregates for concrete can be estimated at 25.9 billion to 29.6 billion tonnes a year for 2012 alone. This represents enough concrete to build a wall 27 metres high by 27 metres wide around the equator."  Sand and gravel are also used land in reclamation, shoreline developments, road embankments, asphalt, and by industries including glass, electronics, and aeronautics.

Dredging sand and gravel from oceans and rivers causes environmental disruption, which can in some cases become severe, leading to problems with erosion, greater vulnerability to storm surges, and destruction of habitat for plant and animals. "Lake Poyang, the largest freshwater lake in China, is a distinctive site for biodiversity of international importance, including a Ramsar Wetland. It is also the largest source of sand in China and, with a conservative estimate of 236 million cubic metres a year of sand extraction, may be the largest sand extraction site in the world. ... Sand mining has led to deepening and widening of the Lake Poyang channel and an increase in water discharge into the Yangtze River. This may have influenced the lowering of the lake’s water levels, which reached a historically low level in 2008 ..." (The Ramsar Convention is the nickname for the Convention on Wetlands of International Importance, which is an intergovernmental treaty for protection of key wetlands.) In general, economic growth in China has been one of the major reasons for the expansion of sand and gravel mining in the last decade.

Or to choose a more extreme case: "In some extreme cases, the mining of marine aggregates has changed international boundaries, such as through the disappearance of sand islands in Indonesia." 
The qualities of sand and gravel matter for their eventual use. For example, "If the sodium is not removed from marine aggregate, a structure built with it might collapse after few decades due to corrosion of its metal structures. Most sand from deserts cannot be used for concrete and land reclaiming, as the wind erosion process forms round grains that do not bind well."

With a combination of research and development into alternative materials, along with different materials methods of landfill and construction, the use of sand and gravel could be reduced. Some possible alternative materials for various uses include quarry dust, incinerator ash, recycled concrete and glass, perhaps finding ways to use desert sand....MORE
Possibly also of interest:
What the Frack? U.S. Silica Up 24% since Feb. 1 IPO (SLCA)
More Natural Gas Needed For Frack Sand Suppliers
Commodities: "Midwest Sees a Sand Rush "