Sustainable Application of Blast Furnace Slag in the Field of 3D Printing: Material Configuration and Machine Optimization

Blast furnace slag is an industrial waste. Its disposition is generally by means of landfilling or stacking, which goes against the concept of sustainable development. In order to maximize its reuse and abate its adverse effects on the natural environment, this study innovated a solution of using blast furnace slag to produce 3D printing materials. Blast furnace slag was mixed with desulfurization gypsum to adapt to the operation of 3D printers. The mixture has fluidity, viscosity, and hydraulicity. Fluidity allows the mixture to smoothly pass through the transportation pipeline and nozzle of the machine; viscosity ensures that the extruded mixture is gradually stacked and settled; hydraulicity guarantees that the mixture solidifies and forms completely solid objects after dehydration and drying. Fully suitable 3D printers are rare in the market. Therefore, the printing nozzle and reserve device of the 3D printer were designed and improved in this study according to the material characteristics, enhancing the smoothness of the mixture during 3D printing. The sustainable application of blast furnace slag in the field of 3D printing not only favors diminishing environmental pollution and resource consumption but also provides a further sustainable production method for human beings.