The calciothermic synthesis of a LaNi5 powder is a complex process requiring careful control of synthesis temperature, holding time, excess of reducing agent, method of compacting a charge, and conditions of hydrometallurgical treatment. This study examines how these factors affect the phase composition and impurity content in LaNi5. It has been found that LaNi5 forms due to the diffusion saturation of solid Ni particles with La from La melt with no impurity phases from the Ca-Ni system. Optimization of synthesis parameters ensures the formation of single-phase LaNi5 at ≥ 1000°C in ≥ 4 hours. It has been found that slaking duration considerably affects oxygen content. Contamination with Fe from crucible material occurs when the synthesis temperature exceeds a certain value. Overall, the study demonstrates that LaNi5 powder with low impurity content possessing high sorption properties can be obtained by providing optimal synthesis conditions and careful post-synthesis treatments such as leaching and slaking.

中文翻译：

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合成参数对钙温法制备的 LaNi5 粉末的物相组成、纯度和结构的影响


LaNi5 粉末的钙热合成是一个复杂的过程，需要仔细控制合成温度、保持时间、还原剂的过量、压实电荷的方法和湿法冶金处理的条件。本研究研究了这些因素如何影响 LaNi5 中的相组成和杂质含量。已经发现 LaNi5 的形成是由于固体 Ni 颗粒与 La 熔体中的 La 扩散饱和，而没有来自 Ca-Ni 系统的杂质相。合成参数的优化确保在 ≥ 1000°C 下≥ 4 小时内形成单相 LaNi5。已经发现，熟化持续时间对氧含量有很大影响。当合成温度超过一定值时，坩埚材料中的 Fe 会受到污染。总体而言，该研究表明，通过提供最佳合成条件和仔细的合成后处理（如浸出和熟化），可以获得具有低杂质含量和高吸附性能的 LaNi5 粉末。