热处理针铁矿的结构与形貌演化  

Structure and Morphology Evolution of Heat Treated Goethite

作　　者：胡绪照 许雪艳 徐兵 廖生温 张佳奇 夏爱林[2] HU Xuzhao;XU Xueyan;XU Bing;LIAO Shengwen;ZHANG Jiaqi;XIA Ailin(School of Mechanical Engineering,Chaohu College,Hefei 238000,China;School of Materials Science and Engineering,Anhui University of Technology,Ma’anshan 243002,China)

机构地区：[1]巢湖学院机械工程学院,合肥238000 [2]安徽工业大学材料科学与工程学院,马鞍山243002

出　　处：《人工晶体学报》2025年第1期165-174,共10页Journal of Synthetic Crystals

基　　金：国家自然科学基金(52272263);巢湖学院学科质量提升工程项目(kj22kctd02)。

摘　　要：采用X射线粉末衍射仪、热重/差热综合分析仪、扫描电子显微镜等研究了针铁矿(α-FeOOH)粉末在250~650℃和900℃高温热处理下的结构与形貌演变。结果表明:针铁矿在250℃煅烧2~8 h未发生明显的相转变,但是随着保温时间的增加,其针状形貌结构逐渐破碎堆叠成短棒状。当煅烧温度为350℃时,α-FeOOH开始脱羟基向赤铁矿(α-Fe_(2)O_(3))转变,且在450℃时完全转变为α-Fe_(2)O_(3)相。煅烧温度升至450~650℃时,虽然产物呈现α-Fe_(2)O_(3)相,但都保持了α-FeOOH原有的针状形貌。随着热处理温度和时间的增加,产物的平均晶粒尺寸逐渐增大。当热处理温度升高时,α-Fe_(2)O_(3)晶体生长变大,比表面积逐渐降低,颗粒间产生烧结现象,且当煅烧温度达到900℃时,破碎棒状结构变成米粒状的α-Fe_(2)O_(3),其在污水处理、光催化和工业颜料等领域具有一定的应用价值。The structure and morphology evolution of goethite(α-FeOOH)powder under high temperature heat treatments at 250~650℃and 900℃were studied by X-ray powder diffraction,thermogravimetric/differential thermal analysis,and scanning electron microscopy.The results indicate that no significant phase transformation occurs in goethite when calcined at 250℃for 2~8 h.However,as the holding time increases,its acicular morphology gradually breaks down and stacks into short rod-like structures.When the calcination temperature reaches 350℃,α-FeOOH begins to dehydroxylate and transform into hematite(α-Fe_(2)O_(3)),and it completely transforms into theα-Fe_(2)O_(3)phase at 450℃.When the calcination temperature reaches 450~650℃,although the product exhibits theα-Fe_(2)O_(3)phase,it retains the original acicular morphology ofα-FeOOH.As the heat treatment temperature and time increase,the average grain size of the product gradually increases.With heat treatment temperatures rising,α-Fe_(2)O_(3)crystals grow larger,the specific surface area decreases progressively,sintering phenomena occur between particles,and when the calcination temperature reaches 900℃,the broken rod-like structure turns into rice-grain-likeα-Fe_(2)O_(3),which has certain application values in fields such as wastewater treatment,photocatalysis,and industrial pigments.

关 键 词：针铁矿 热处理 高温相变 米粒状α-Fe_(2)O_(3) 

分 类 号：P579[天文地球—矿物学]