摘要
为了在不降低镁钙高温性能的同时改善合成镁钙砂的烧结性能,以辽宁大石桥菱镁矿细粉(≤0.075 mm)、化学纯Ca O为原料,经湿磨消化、轻烧(分别于650和900℃保温40 min)、成型、不同温度煅烧(1 400、1 500、1 600和1 650℃保温3 h),研究了Ca(OH)_2-菱镁矿混合粉体的轻烧热分解进程及其对合成镁钙砂烧结性能的影响。结果表明,Ca(OH)_2的"分解-碳酸化-再分解"反应对混合粉体的热分解进程、轻烧粉体的结构及烧结性能有重要影响;Ca(OH)_2的引入可明显降低菱镁矿分解温度,防止轻烧粉体中"母盐假象"的形成,提高轻烧粉的均匀性,明显改善镁钙砂的烧结性能,促进合成镁钙砂的烧结致密化;Ca O含量(w)为20%的试样,经消化、900℃保温40 min轻烧、1 650℃保温3 h烧后,体积密度达3.34 g·cm^(- 3),显气孔率为2.2%。
In order to improve the sinterability of synthesized magnesia-calcia clinker and keep the high tem-perature properties,the light-burnt process and the effect on sinterability of synthesized MgO-CaO materials were researched using magnesite fines （≤0.075 mm） and chemical pure CaO as staring materials. They were wet milled,slaked, light-burnt （650,900 ℃ for 40 min, respectively）,shaped,calcined at 1 400,1 500, 1 600,and 1 650 ℃ for 3 h,respectively. The results show that the udecomposition-carbonation-decomposition” cycle of Ca（〇H）2 affects the thermal decomposition process of the mixed powder,the structure and sinterability of the light-burnt powders greatly. The introduction of Ca（OH）2 can obviously decrease the de-composition temperature of magnesite,avoid the ≤mother salt illusion≤ in the light-burnt powders,enhance the uniformity of the light-burnt powders,improve the sinterability and the densification of MgO-CaO clink-ers. The specimen with 20 mass% of CaO,slaked,light-burnt at 900 ℃ for 40 min and insulated at 1 650 ℃ for 3 h has 3.34 g · cm3 of bulk density and 2.2% of apparent porosity.
出处
《耐火材料》
CAS
北大核心
2016年第4期261-264,268,共5页
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