MgO is industrially produced from seawater or dolomite as the raw material. MgO synthesized from seawater has a relatively low impurity concentration. However, these impurities strongly affect the fine structure and physical properties (especially the thermal conductivity) of MgO. In this research, the influence of impurity concentration on the MgO grain growth and its thermal conductivity was investigated. The processing conditions for MgO powder synthesis were optimized by a polymer complex method using magnesium nitrate hydrate, citric acid, ethylene diamine, and chemical compounds containing B, Ca, or Si, which are the main impurities of MgO produced from seawater. The morphology and phase composition of the MgO powders were investigated by X‐ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), and energy dispersive X‐ray spectroscopy (EDS). The morphological changes and differences in the thermal conductivity of MgO crystalline systems containing impurities (B, Ca, and/or Si) were clarified, and the relationship between the fine structure of MgO crystals containing impurities and their thermal conductivities was described in detail.

中文翻译：

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含各种杂质（B，Ca，Si）的MgO晶体的形貌变化及其热导率

MgO以海水或白云石为原料工业生产。由海水合成的MgO的杂质浓度相对较低。然而，这些杂质强烈地影响了MgO的精细结构和物理性质（特别是热导率）。在这项研究中，研究了杂质浓度对MgO晶粒生长及其热导率的影响。通过使用硝酸镁水合物，柠檬酸，乙二胺和含有B，Ca或Si的化合物（它们是从海水中产生的MgO的主要杂质）的聚合物络合方法，优化了MgO粉末合成的工艺条件。通过X射线衍射（XRD），场发射扫描电子显微镜（FE-SEM）对MgO粉末的形貌和相组成进行了研究，透射电子显微镜（TEM）和能量色散X射线光谱（EDS）。阐明了含杂质（B，Ca和/或Si）的MgO晶体体系的形貌变化和导热系数的差异，并详细描述了含杂质的MgO晶体的精细结构与其导热系数之间的关系。