China is implementing a large-scale circular economy initiative by converting coal gangue into construction sand. The country possesses approximately seven billion tons of these recycled coal waste materials. By utilizing this alternative, China aims to meet the rising demand for building materials while reducing reliance on traditional sand mining. This strategic shift is expected to protect river ecosystems from the environmental damage caused by sand extraction. Additionally, the process is designed to be economically viable, potentially generating revenue from waste. The project serves as a primary example of how industrial waste can be repurposed for urban development. This approach effectively integrates environmental protection with industrial necessity.