鋁酸鈉溶液種分過程中草酸鈉結晶析出的行為

Behavior of sodium oxalate in seeded precipitation process of sodium aluminate solution

School of Metallurgy and Environment, Central South University, Changsha 410083, China

摘要: 拜耳法氧化鋁生產過程中，草酸鈉在鋁酸鈉溶液晶種分解工序造成諸多負面影響.本文對種分過程草酸鈉結晶析出的行為進行研究.用含草酸鈉的合成和工業鋁酸鈉溶液分別進行分解實驗，考察草酸鈉對分解產物粒度和形貌的影響，并對草酸鈉的結晶習性、草酸鈉與氫氧化鋁之間的相互作用規律進行探究.結果表明，草酸鈉在氫氧化鋁表面或顆粒間隙結晶析出，使氫氧化鋁二次成核增加，并嚴重阻礙氫氧化鋁的附聚，這是其造成產品氫氧化鋁粒度細化的主要原因.
- 鋁酸鈉溶液 /
- 晶種分解 /
- 草酸鈉 /
- 粒度
Abstract: Sodium oxalate has negative effects on alumina produced by the Bayer process. The behavior of sodium oxalate in the seeded precipitation process of a sodium aluminate solution was investigated. The particle size and morphology of crystallization, as well as the crystal habit of sodium oxalate, and the interaction between sodium oxalate and gibbsite in synthetic or industrial sodium aluminate solutions were also investigated. The results show that sodium oxalate precipitates on the surface or gibbsite clearance, such that the secondary nucleation of gibbsite increases, and the agglomeration of gibbsite is seriously hindered. This is considered as the main cause of gibbsite refinement.
- sodium aluminate solution /
- seeded precipitation /
- sodium oxalate /
- granularity

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