用石煤提钒酸浸渣制备蒸压砖

Research on Preparation of Autoclaved Brick from Stone Coal Acid-Leaching Vanadium Tailings

以石煤提钒酸浸渣为主要原料、粉煤灰和消石灰为辅助原料,采用压制成型法制备蒸压砖,当酸浸渣、粉煤灰和消石灰的质量分数分别为62%、20%和18%,成型水固比为16%,成型压力为15 MPa,蒸压养护压力和时间分别为1.2 MPa和6 h时,制品抗压强度可达到《GB11945—1999蒸压灰砂砖》规定的MU15标准。XRD和SEM分析结果表明:制品水化前期主要是生成Ca(OH)2凝胶相;经过蒸压养护后,酸浸渣中的玻璃微珠提供的活性SiO2与Ca(OH)2凝胶相反应生成纤维状水化硅酸钙和针叶状托贝莫来石等水化产物,这些水化产物将未反应的酸浸渣粗料紧紧黏结在一起,使制品结构紧密,具有较高的强度。

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 com- bine with the unreacted coarse ingredients so that the product possesses a high strength with tight structure.