低钙铝酸钙熟料的物相转变和浸出性能

以分析纯CaCO_3,Al_2O_3和SiO_2为原料,研究了n_(CaO)/n_(Al2O3)=1.0,w_(Al2O3)/w_(SiO2)=3.0时物料的熔化温度以及熟料的物相组成、自粉化性能和氧化铝浸出性能.结果表明:物料熔化温度为1 392℃;烧结温度为1 350℃时熟料物相为CaAl_2O_4,Ca_(12)Al_(14)O_(33)和γ-Ca_2SiO_4,自粉化性能和氧化铝浸出性能良好,氧化铝浸出率为93.37%;1 400℃物料局部熔化,非均相的形成造成物料扩散受阻和物相分布不均匀,阻止β-Ca_2SiO_4向γ-Ca_2SiO_4转化,熟料自粉化性能变差,且有Ca_2Al_2SiO_7生成,二者均使氧化铝浸出性能变差,氧化铝浸出率仅为74.50%;1 450℃物料完全熔化,熟料自粉化性能和氧化铝浸出性能得到改善.

Phase Transformation and Leaching Property of Low-Lime Calcium Aluminate Clinker

The melting temperature， mineral phases， pulverization and alumina-leaching properties of clinkers were studied by using analytical reagent CaCO₃， Al₂O₃ and SiO₂ as raw materials. The molar ratio of CaO to Al₂O₃ is 1.0 and the mass ratio of Al₂O₃ to SiO₂ is 3.0. The results showed that the melting temperature of the sample is 1392℃. The clinker sintered at 1350℃ is composed of CaAl₂O₄， Ca₁₂Al₁₄O₃₃ and γ-Ca₂SiO₄， which has good pulverization property and alumina leaching rate of 93.37%. The materials melt locally and turn into heterogeneous phases at 1400℃， which blocks the elemental diffusion， results in non-homogeneous phases， and inhibits the conversion of β-Ca₂SiO₄ to γ-Ca₂SiO₄. The formation of Ca₂Al₂SiO₇ and deterioration of pulverization property sintered at 1400℃ are the main reasons for the low alumina leaching rate of 74.50%. The clinker sintered at 1450℃ melts completely， which improves the pulverization property and the alumina leaching property of clinker.