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 粉末的钙化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、压实炉料的方法以及湿法冶金处理的条件。本研究研究了这些因素如何影响 LaNi₅ 中的物相组成和杂质含量。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 ≥4 小时内在 ≥1000°C 下形成单相 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），可以获得杂质含量低、吸附性能高的 LaNi₅ 粉末。