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为了获得高致密度、低气孔率和抗水化性能良好的CaO砂,以活性石灰(≤20 mm)为主要原料,分析纯Zr(OH)4(w(Zr(OH)4) ＞97％,d5o=15.68 μm)为添加剂,研究了Zr(OH)4添加量(w)为0、0.5％、1％、2％、3％和5％及煅烧温度为1 450、1 550和1 650℃时对CaO砂烧结性能和抗水化性能的影响.用煮沸法测试试样的抗水化性能,采用XRD进行物相组成分析,采用SEM分析试样的显微结构.结果表明:1)添加0.5％(w)Zr(OH)4的烧后试样的显气孔率较低,体积密度较大,水化质量增加率与粉化率较低,抗水化性能较好.2)CaZrO3的生成降低了游离CaO的数量.Zr(OH)4加入量较少时,CaZrO3产生7％ ～8％的体积膨胀,降低了显气孔率,提高了体积密度,促进了晶粒的生长,从而提高了抗水化性能.但是生成量过多反而会抑制CaO晶粒的生长,且导致试样结构疏松,对抗水化性能不利.3)CaZrO3主要分布在CaO的晶界与晶粒中,添加0.5％(w)Zr(OH)4的试样在1 450、1 550和1 650℃煅烧后的晶粒尺寸分别为42.7、65.5和68.6 μm.当煅烧温度增加到1 550℃时已经达到较大的晶粒尺寸,且其体积密度也达到了CaO理论密度的94.6％,继续提高温度对晶粒尺寸及体积密度的增加影响不大.

To obtain high-density,low-porosity and good hydration-resistant CaO clinker,the effects of Zr(OH)4 additions (0,0.5％,1％,2％,3％,and 5％,by mass,the same hereinafter) and calcination temperatures (1 450,1 550,and 1 650 ℃) on sintering property and hydration resistance of CaO clinker were researched using active lime (≤ 20 mm) as the main starting material and analytically pure Zr (OH)4 (Zr(OH)4 ＞97 mass％,d50 =15.68 μm) as an additive.The hydration resistance of the CaO clinker was tested by the boiling method.The phase composition and microstructure of the CaO clinker were characterized by XRD and SEM,respectively.The results show that:(1) the calcined specimen with 0.5％ Zr(OH)4 has low apparent porosity,high bulk density,low hydration mass gain rate,and low pulverization rate,indicating good hydration resistance;(2) free CaO is decreased due to the generation of CaZrO3 in the specimens.7％-8％ volume expansion caused by the formation of CaZrO3 contributes to the decreased porosity and increased density,promoting the grain growth and thus improving the hydration resistance;but excessive zr(OH)4 inhibits CaO grains growth and results in loose structure,which is harmful to the hydration resistance;(3)CaZrO3 is mainly distributed in the grain boundaries and grains of CaO;the average grain size of the CaO specimens with 0.5％ Zr(OH)4 addition calcined at 1 450,1 550,1 650 ℃ is 42.7,65.5,68.6 μm,respectively;when the calcination temperature increases to 1 550 ℃,the grain size is large and the bulk density reaches 94.6％ of the theoretical density of CaO;so further increasing temperature has slight effect on the grain size and bulk density of the specimens.