In a step that could spark a transformation in the global construction industry, a research team from the Korea Institute of Ocean Science and Technology (KIOST) has successfully developed a new device that uses ultrasonic waves to remove salt from sea sand, reducing salinity to just 0.04%—the safe threshold for use in reinforced concrete.
River Sand Crisis Drives the Search for Alternatives
The construction industry worldwide is facing an increasing shortage of river sand due to over-extraction and environmental restrictions. This has prompted the search for alternatives, with sea sand emerging as a potential option. However, the main obstacle lies in the salts present in sea sand, which cause corrosion of reinforcing steel in concrete. This not only weakens structural durability and reduces lifespan but also poses serious economic and engineering risks.
In this context, researchers at the Korea Institute of Ocean Science and Technology developed a device that uses ultrasonic waves to wash sea sand, lowering its salinity to the safe threshold within just a few minutes. This breakthrough paves the way for the sustainable and safe use of these resources. The study was published in the journal Scientific Reports, confirming the effectiveness of the technique under efficient experimental conditions.
An Innovative Sand-Washing Technology
Traditional methods for desalinating sea sand require massive amounts of water—up to 4 tons of water to wash just 1 ton of sand. These methods are slow and unsustainable, particularly in regions suffering from water scarcity.
The newly developed device, created by Dr. Gil Lim Yoon and his colleagues at KIOST, relies on ultrasonic cavitation washing, which removes particles effectively through bubble collapse. This contact-free cleaning process ensures precision and efficiency.
The process involves mixing sand and water at a ratio of 1:2, then applying ultrasonic waves at 300 watts for just 3 minutes. This reduces salinity to the recommended level of 0.04%, as set by Korea’s Ministry of Land, Infrastructure, and Transport.
The method offers both practical and economic benefits, providing a viable solution to the global shortage of river sand while ensuring structural safety and delivering higher economic returns.
KIOST also plans to further develop the technology to enable the treatment of larger quantities of sand in less time, potentially making it a key option for future infrastructure projects.
A Step Toward More Sustainable Construction
Construction experts believe that using desalinated sea sand through this technology could extend the lifespan of buildings and enhance their safety. It would also help reduce pressure on scarce natural resources, which are increasingly threatened by climate change.
With global demand for infrastructure on the rise, this device could become a critical tool in striking a balance between the need for construction materials and the imperative of environmental preservation.
