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采用溶胶_凝胶水热法合成了单相黄铁矿结构的FeS2 粉晶 .用x射线衍射、傅氏变换红外光谱等分析手段对FeS2 粉晶进行了表征 ,以简化的数学模型及相变理论讨论了晶体生长过程 .结果表明 :FeS2 晶粒的生长过程属于相变与扩散的混合机制 ,符合经时间指数修正的二次方动力学方程 ,是一个生长速率随时间变化的过程 ;水热晶化温度高于 4 5 3K、反应时间超过 18h且有适量的硫参与反应时 ,可得到单相的黄铁矿型的FeS2 .该过程可分为三个阶段 :前期为白铁矿和黄铁矿的成核孕育阶段 ,中期为FeS2 晶核以黄铁矿吞并白铁矿的相变方式逐渐长大的阶段 ,后期为小晶粒融合而大晶粒继续长大的扩散生长过程 .
The FeS2 powder crystal with single phase pyrite structure was synthesized by sol-gel hydrothermal method. The FeS2 powder crystal was characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The simplified mathematical model and phase transition The growth process of the crystal is discussed theoretically.The results show that the growth process of FeS2 belongs to the mixing mechanism of phase transformation and diffusion and accords with the quadratic kinetic equation corrected by time index and is a process of the growth rate changing with time. When the crystallization temperature is higher than 453K and the reaction time is over 18h and the appropriate amount of sulfur is involved in the reaction, a single phase pyrite type FeS2 can be obtained. The process can be divided into three stages: the early stage is white iron ore and yellow During the nucleation stage of iron ore, the phase of FeS2 nucleus gradually grew up with the transformation of pyrite into white iron ore, and the later was the process of diffusion growth of large grains that continued to grow up with small grains being fused.