The impact of zinc (Zn) on the seed decomposition process of sodium aluminate solution at different caustic concentrations was investigated. The results showed that as the concentration of Zn(II) in sodium aluminate solution increased from 0 to 1000 mg/L, the decomposition efficiency of the solution and average grain size of the resulting aluminum tri-hydroxide (ATH) changed little at a caustic concentration of 141 g/L. At caustic concentrations of 160 g/L and 177 g/L, the decomposition efficiency increased from 35.8% and 21.6% to 40.6% and 24.9%, respectively, while average grain size of the ATH crystal seeds increased from 14.2 and 9.25 μm to 17.9 and 15.9 μm, respectively. The XRD, FT-IR, and SEM analyses showed that zinc can enter the ATH seeds and interact with the α-ATH crystal planes. It may also form interactions with the AlO octahedral growth structure, thus promoting solution decomposition and influencing crystal growth. The research results will provide valuable references for improving the quality of alumina products.

中文翻译：

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锌 (II) 和碱含量对铝酸钠溶液分解的影响及其与拜耳法的相关性

研究了锌（Zn）对不同碱浓度下铝酸钠溶液晶种分解过程的影响。结果表明，随着铝酸钠溶液中Zn(II)浓度从0 mg/L增加到1000 mg/L，在苛性碱条件下溶液的分解效率和生成的氢氧化铝(ATH)的平均晶粒尺寸变化不大。浓度为141克/升。当碱浓度为160 g/L和177 g/L时，分解效率分别从35.8%和21.6%增加到40.6%和24.9%，而ATH晶种的平均晶粒尺寸从14.2和9.25 μm增加到17.9分别为 15.9 微米和 15.9 微米。XRD、FT-IR 和 SEM 分析表明，锌可以进入 ATH 晶种并与 α-ATH 晶面相互作用。它还可能与Al2O八面体生长结构形成相互作用，从而促进溶液分解并影响晶体生长。研究结果将为提高氧化铝产品质量提供有价值的参考。