| Fe3+/Ba2+/Co2+/Zn2+/Cu2+在NH4HCO3-NH3·H2O和NaOH-Na2CO3体系中的热力学分析 |
| Thermodynamic Analysis on Solubility of Fe3+/Ba2+/Co2+/Zn2+/Cu2+ in NH4HCO3-NH3·H2O and NaOH-Na2CO3 System |
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| 摘要: 通过对Fe3+/Ba2+/Co2+/Zn2+/Cu2+在NH4HCO3-NH3·H2O和NaOH-Na2CO3体系中的热力学分析,得到各金属离子总浓度(cMe)与pH值的关系,确定了2种体系中5种离子完全共沉淀的pH值范围。结果表明：在NH4HCO3-NH3·H2O体系中，Co2+、Zn2+、Cu2+ 3种离子和氨的配位能力很强，其中Cu2+与氨的配位能力最强，在相同的pH值条件下，Cu2+沉淀困难，5种金属离子的完全共沉淀区域由Cu2+决定。在NaOH-Na2CO3体系中，随总碳浓度(cC)的增加，Ba、Co、Zn、Cu的溶解度都随之减小，当cC=1.0 mol·L-1时,各金属离子完全共沉淀的pH值范围为7.5~11。在两种体系中，Fe的溶解度都是随pH值的增大而减小,最终达到平衡。以NaOH-Na2CO3为沉淀剂，在pH=10.0的条件下，采用化学共沉淀法合成出了晶粒细小、粒度均匀的Y型纯相结构的平面六角铁氧体微粉。 |
| 关键词: 平面六角铁氧体 化学共沉淀 溶解度 热力学分析 |
| 基金项目: |
| Abstract: The pH-dependence of cMe in NH4HCO3-NH3·H2O and NaOH-Na2CO3 system were respectively presented by thermodynamic analysis, and the co-precipitation window of Ba2+/Fe3+/Co2+/Zn2+/Cu2+ was obtained at a suitable pH. The results show that Co2+, Zn2+ and Cu2+ ions have strong complexity with NH3 in the NH4HCO3-NH3·H2O system. Especially the copper ion is strongest. In the same pH, the copper ion is difficult to completely precipitate. So the co-precipitation window of the five kinds of metal ions is controlled by the pH for completely precipitation of Cu2+ in the system containing NH3. In the NaOH-Na2CO3 system without ammonia, the solubilities of Ba, Co, Zn and Cu are reduced with the increase of carbon concentration cC. The pH window of the five kinds of metal ions are just determined by the cC. When the cC is 1.0 mol·L-1, they can be completely co-precipitated at pH of 7.5~11. The solubility of the iron ion is reduced with the pH increase of solution in the two systems, and reached equilibration finally. The Y-type hexaferrite powders with uniform and fine size are obtained at pH value 10.0 in the NaOH-Na2CO3 system. |
| Keywords: planar hexagonal ferrite chemical co-precipitation solubility thermodynamic analysis |
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| 蔡进红,代建清,陈文国,周小兵.Fe3+/Ba2+/Co2+/Zn2+/Cu2+在NH4HCO3-NH3·H2O和NaOH-Na2CO3体系中的热力学分析[J].无机化学学报,2009,25(5):886-892. |
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