150 t超高功率电弧炉整体浇注小炉盖的研制与应用

以特级矾土、电熔棕刚玉、电熔白刚玉等为主要原料，加入一定量的α Al2O3微粉和氧化铬微粉，用纯铝酸钙水泥作结合剂，外加微量防爆纤维、不锈钢纤维和分散剂，制作整体浇注的电弧炉小炉盖。研究了α Al2O3微粉和氧化铬微粉对试样冷热态强度性能、致密性、施工性能的影响；对比了Polyg、Darvan和M（复合型）分散剂的效果，最终筛选出最佳组合方案：α Al2O3微粉合适加量为2a%，氧化铬微粉合适加量为2c%；分散剂选用M型粉末。采用该组合方案制作的预制件试样性能完全满足了实际需要。采用该方案制作的整体浇注小炉盖应用于国内某钢厂150 t超高功率交流电弧炉，其使用寿命由原平均180炉左右提高到537炉，最高达到676炉，效果非常理想。

Study and Application of Integrative Casting Lid of 150 t UHP-EAF

Integrative casting lid of UHP EAF were prepared by the raw materials such as bauxite, fushed brown alumina, fushed white alumina, and calcium aluminate cement with the addition of α Al2O3 and Cr2O3 powder, and minim anti exploding fibre, stainless steel fibre and dispersant. The influences of α Al2O3 and Cr2O3 powder on the cold and hot crushing strength, density and workability of the castable were investigated. In contrast with Polyg, Darvan and M(compound) dispersant, It is found that the best content of α Al2O3 and Cr2O3 powder are 2a% and 2c%, and the most efficient dispersant is M. After the casting lid made by this design were used on 150t UHP EAF in some domestic steel plant，and the practice shows excellent result that the precasted lid survives averagely 537 batches and the longest life is 676 batches, while the brick layed lid can only survived 180 batches.