摘要
以分析纯化学试剂CaO、Al_2O_3、SiO_2和B_2O_3为原料,研究添加不同B_2O_3含量的CaO-Al_2O_3-SiO_2三元系在1350℃烧结时铝酸钙熟料的自粉性能、物相形成规律、微观组织形貌及其元素分布和Al_2O_3的浸出性能,并通过XRF、XRD和SEM-EDS等手段探讨其作用机理。结果表明:B_2O_3促进2CaO.Al_2O_3·SiO_2的生成,并抑制β-2CaO·SiO_2向γ-2CaO.SiO_2的转变,明显降低熟料的自粉性能;B_2O_3在铝酸钙熟料中均匀分布,其加入使铝酸钙熟料中12CaO·7Al_2O_3和CaO·Al_2O_3的晶胞参数增加,固溶至铝酸钙晶体中引起晶胞的扩胀;铝酸钙熟料的Al_2O_3浸出率随着B_2O_3含量的增加急剧下降,当B_2O_3添加量由0增加到0.20%(质量分数)时,Al_2O_3浸出率由95.01%降低至72.03%,添加B_2O_3后铝酸钙熟料中生成的2CaO·Al_2O_3·SiO_2和难以浸出的12CaO·7Al_2O_3是其Al_2O_3浸出率明显降低的主要原因。
Calcium aluminate clinkers containing different contents of B2O3 in CaO-Al2O3-SiO2 system sintered at 1350℃were obtained by using analytical reagents of CaO, Al2O3, SiO2 and B2O3 as raw materials. The pulverization, mineralogical formation characteristic, microstructure, elemental distribution and alumina leaching property of clinkers were studied by XRF, XRD and SEM-EDS. The results show that B2O3 promotes the formation of 2CaO？Al2O3？SiO2 and inhibits the conversion of β-2CaO？SiO2 to γ-2CaO？SiO2, which deteriorates the pulverization property of calcium aluminate clinker. B2O3 distributes uniformly in the calcium aluminate clinker, and the crystal parameters of 12CaO？7Al2O3 and CaO？Al2O3 increase with the increase of B2O3 addition, indicating that B2O3 forms solid solutions in calcium aluminates to increase their crystal cell parameters. The Al2O3 leaching rate of calcium aluminate clinkers decreases quickly with the increasing of B2O3 addition, which decreases from 95.01% to 72.03% as the B2O3 addition increases from 0 to 0.20%（mass fraction）. The main reason of the obvious decrease in the Al2O3 leaching rate of calcium aluminate clinker is the formation of 2CaO？Al2O3？SiO2 and the unleached 12CaO？7Al2O3 in sodium carbonate solution.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2014年第6期1663-1670,共8页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(51374065
51174054)
