The carburization roasting treatment followed by the magnetic separation is an effective way to utilize low-grade siderite, in which the sodium sulfate additive plays an important role. In order to investigate the role of sodium sulfate additive, the present study fixes its particular attention on the function mechanism of sodium sulfate additive during the preheating treatment, carburization, and separation process. The results show that sodium sulfate additive can enhance the oxidation, reduction, and carburization reactions of siderite pellet, which dramatically increases the carburization rate and degree of siderite pellet. Besides, sodium sulfate additive can significantly improve the growth of iron carbide particle, transform the dense gangue into loose gangue, and produce the cracks inside pellet, which greatly promotes the separation of iron carbide and gangue. In the whole process, preheating treatment at high temperature is a necessary process to intensify and maintain the additive’s effects.

中文翻译：

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硫酸钠添加剂在低品位菱铁矿制备碳化铁中的作用机理

渗碳焙烧后磁选是利用低品位菱铁矿的有效途径，其中硫酸钠添加剂起着重要作用。为了研究硫酸钠添加剂的作用，本研究特别关注硫酸钠添加剂在预热处理、渗碳和分离过程中的作用机理。结果表明，硫酸钠添加剂可以增强菱铁矿球团的氧化、还原和渗碳反应，显着提高菱铁矿球团的渗碳率和渗碳程度。此外，硫酸钠添加剂可以显着改善碳化铁颗粒的生长，将致密的脉石转变为松散的脉石，并在球团内部产生裂纹，极大地促进了碳化铁和脉石的分离。在整个过程中，高温预热处理是强化和保持添加剂作用的必要过程。