Low-Density and High-Strength Fracking Proppant Made by High-Alumina Fly Ash

High-alumina fly ash is defined to have alumina (Al 2 O 3 ) content of no less than 40%, according to the Chinese power industry standard DL/T 2297. Specification for resource utilization categorization of fly ash from coal-fired power plant (Standard No. DL/T 2297-2021), and is considered a valuable raw material to replace bauxite for making aluminum, refractory materials, and fracking proppants, etc. A low-density and high-strength proppant, conventionally made with bauxite, has been successfully made by high-alumina fly ash and commercially used in the market. This new high-alumina fly-ash–derived proppant has some advantages compared with the bauxite-derived proppant: (1) lower raw material cost, (2) fewer processing steps and less energy consumption, (3) equal or better performance.