For more than just sandcastles

Materials World magazine
,
1 Aug 2017

High demand for sand in the construction and electronics industries is a mounting problem for sustainability, as Ellis Davies reports.

At first glance, sand may not seem like a terribly important material. However, sand is used in many modern day applications and materials, such as glass, electronics and construction. With surges in the rate of construction in countries such as China and Singapore, the demand for sand has soared to an unsustainable level, with approximately 30 billion tonnes of sand used in construction each year. A rush of illegal mining has inevitably followed the increased demand for sand. Not only is this environmentally detrimental, because mining is occurring without limit and regulation, but it has also put communities at risk of violence. 

With the question of sustainability hanging in the air, and a growing negative press over the shady areas of sand mining, steps need to be taken to curb excessive mining and regulate illegal sites. The United Nations Environmental Programme (UNEP) paying particular attention to the industry in an attempt to inform governments and communities of the potential environmental damage.

A growing demand

Singapore has the third-highest population density in the world, with 7,987.52 people per square kilometre and an average population growth rate of 1.92%. The country is small, but, since independence in 1965, it has expanded its territory by 22% (710km2) by pouring sand into the sea. The sand for this venture has been imported from Malaysia, Thailand, Indonesia and Cambodia. Land reclamation schemes can also be found in Japan and China – Tokyo bay has expanded by 249km2 since the 19th Century, and 129km2 has been reclaimed near Shanghai for the development of a new city.

The largest extraction site in the world is located at China’s Lake Poyang, which has provided large quantities of sand for the country’s large infrastructure projects, such as the Three Gorges Dam or for the construction of ‘megacities’. Making plain the scale of extraction carried out in the country, Pascal Peduzzi, Director of Grid Geneva (UNEP), told Materials World, ‘China has extracted, and used, more sand in the last four years than the USA has in one century.’ Peduzzi also highlighted other examples of vast sand use, such as the Palm Islands in Dubai, UAE, which used 1.2 billion tonnes for each of the three palms.

With such a high annual usage, environmental impacts are inevitable. Removing sand from an ecosystem can affect the local wildlife, infrastructure and flood defence. For example, Kerkennah, Tunisia, has experienced salinisation of the aquifer and a greater risk of coastal flooding because of the small amount of sand extracted from beaches to build houses. In order for sand mining to continue, sustainability plans must be put in place.

Sustainable mining

Despite popular assumption, sand is a finite resource. The production of sand is very slow, caused by lengthy natural processes of erosion and weathering. Therefore, mine sites need to preserve the surrounding environment. 

Peduzzi places focus on knowledge and administrative systems, pointing out that due to the slow production of sand, it comes down to calculating the amount of sand that can be extracted from a given area, as all differ. ‘There must be a tremendous amount of research carried out on the amount of sand that can be extracted in a given area without having a large impact on the environment,’ he said. As an example, Peduzzi highlighted the current UK system for sand mining. ‘In the UK, if you want to extract sand you need to apply for a license – there will be an environmental impact assessment to decide the amount of sand that can be mined without impacting the area.’

The UNEP aims to work with governments to help them tackle the issues created by sand mining, as it rarely features as a priority. ‘It is quite difficult to bring up sand mining as a new subject, as there are so many things for governments to deal with. It is very hard to approach them with another problem, particularly if you are not always presenting a solution,’ said Peduzzi. The organisation is currently bringing the issue to the EU parliament, suggesting potential solutions such as the circular economy. ‘It is similar to fishing or deforestation, whenever we use more of a resource than can be produced in one year, we are heading towards unsustainable development,’ said Peduzzi.

Sand is gold

The United Nations has estimated that illegal sand mining poses a threat to 70% of the world’s beaches. India faces a particularly fierce bout of illegal mining, which fetches an estimated US$250 million per year, despite regulations put in place in 2016. A sand mining approval and tracking system has been implemented in India, but Maharashtra is the only state with a specialised mechanism to tackle the issue. The state employs a method that cordons off an area of mining so that there is only one way in and out. This entrance/exit is monitored at all times via CCTV, and the district collector and police services are deployed to the site to apprehend any violators.

Elsewhere, accounts of illegal mining are common. One such account, written by freelance journalist Sandhya Ravishankar in a four part series for The Wire, follows and implicates the actions of Tirunelveli-based mining baron S Vaikundarajan. Ravishankar recalls her experiences in areas of illegal sand mining, including threats of violence, abuse and repeated attempts by the mafia to discredit her. Interference in the work of India’s ‘sand mafia’ has led to death for some, with a number of murders being linked to the organisation, including that of 52-year-old Paleram Chauhan from Noida, who was shot as he disputed the mining of communal village land. 

Peduzzi recalled for Materials World his first encounter with illegal sand mining. ‘In 2009 I was working in Jamaica, investigating a beach on the west coast that was eroding very fast, and the people wanted to find out why. We surveyed the area using a series of measurements and questioned many people, and found out that it was because of the destruction of the habitat. Just south was a small fishing village, and the locals told us that one night some people came with guns and trucks and took the beach away overnight. I was amazed that someone would use threats of violence just to get sand. How much value can sand really have? I did not, at the time, understand why anyone would steal sand.’ 

Sand has become money, power and influence. With enough sand extracted each year to build a 20 x 20m wall around the equator, the industry needs to be monitored to avoid illegal activity and unsustainable development. Plans are in place, but demand is high, and there’s money to be made.

Mineral Sands

Greater manufacturing of electronic devices has also increased demand for mineral sands such as titanium dioxide and zircon, although this remains small in comparison to that of the construction industry – 180 million tonnes per year. 

Sustainable mineral sand mining can be seen in Senegal, at the TiZir Limited, UK, Grand Cote (GC) project. The GC project is a mineral sand mine extracting zircon, rutile, leucoxene and ilmenite for the electronics industry, covering an area of 100 x 4km with a 25-year reserve. The extraction site is a dredge, and therefore is always moving at a pace of roughly 20m per day. This movement allows the land already mined to be replenished almost immediately. Jean-Michel Fourcade, CEO of TiZir Limited, explained. ‘As soon as the mine has advanced, the rejection area [where 98% of sand is put after being separated in a concentration process] is rejuvenated by implementing various species of plants that are prepared in a nursery. I would say that the area is greener after our involvement than it was before. We do not need to wait until the mining is entirely finished – the rehab is done continuously.’ 

TiZir does not use any chemicals in the mining and separation process. Extraction is conducted using pumps and water sourced from an aquifer 500m below the ground, within limits allowed by permit. Separation uses mechanical and physical properties to extract the different forms of mineral sand. ‘If you use wet sand mixed with water using spirals you will be able to separate the heavy from the lightest product. The same can be applied once the concentrate is dry, you just have to place it within a magnetic or electrostatic field,’ Fourcade explained.

The company has a system in place to communicate with local communities should the need for relocation arise, and local authorities are consulted and kept informed on the mine's progress.