Mechanical Method for Turning Hong Kong Soils into Construction Materials Including Sand

Sand is the most exploited raw solid material in the world. It can be used for construction of buildings, roads, railways, bridges, tunnels and beaches. According to United Nations’ reports in 2019 and 2022, the world is facing a shortage crisis of sand, as one of the greatest sustainability challenges of the 21st century. Such sand shortage crisis around the world has affected the use of sand in Hong Kong since Hong Kong does not produce any sand. This paper presents a newly invented method for turning Hong Kong soils into construction materials including sand. The local completely decomposed granitic soil and volcanic soil in Hong Kong can be mechanically turned into the materials of gravel, sand, silt and clay. The gravel, sand and silt are siliceous solid particles and mainly quartz mineral particles. The clay is mainly kaolinite mineral. These materials with known and narrow particle size ranges can be used as the raw solid materials in construction and other industry. The method presented in this paper can offer a new sustainable and environmental-friendly and economic solution to the world’ sand shortage crisis.