Abstract: Stone coal acid-leaching vanadium tailings was used as the main material with fly ash and slaked lime as the auxiliary materials in preparation of autoclaved bricks by press shaping. When the content of tailing, fly ash and slaked lime is 60%, 20% and 18%, respectively, forming pressure is 15 MPa, the steam pressure is 1.2 MPa for 6 h steaming, the compressive strength of the product is up to the requirements of MU15 brick stipulated in nation standard “GB 11945-1999 Autoclaved Lime-sand Brick”. XRD and SEM analysis indicate that the product is mainly to generate Ca(OH)₂ gel phase in the early hydration. After the autoclave of the product, the active silicon dioxide provided by glass microsphere in the tailings and Ca(OH)₂ gel phase generates fibrous C-S-H and needles of shape mendicant mullite, which closely combine with the unreacted coarse ingredients so that the product possesses a high strength with tight structure.  

Key words: Stone coal acid leaching vanadium tailings, Autoclaved bricks, Ratio of materials, Water-solid ratio, Forming pressure