结晶法脱除某铝酸钠溶液中的有机物

Removal of Organics From Industrial Sodium Aluminate Solution by Crystallization Process

拜耳法生产氧化铝过程中,铝酸钠溶液中的有机物对生产有负面影响。研究了采用结晶法脱除某铝厂分解母液中的有机物,考察了母液苛性碱质量浓度、时间、晶种量、温度对脱除有机物的影响,分析了浓缩渣的物相组成和显微形貌。结果表明:用结晶法可脱除部分有机物;较佳的结晶条件为苛性碱质量浓度360g/L,结晶温度60℃,晶种添加量40g/L,结晶时间12h。最佳条件下,草酸钠脱除率为28.40%,总有机碳脱除率为25.74%;浓缩渣产物的结晶形态以附聚物为主,含不同组成和结构的有机物,主要为酯类、酸类、酮类等。

In Byer process, the organics in sodium aluminate solution may cause a series of negative effects. By crystallization process, the effects of alkali concentration, crystallization time, the amount of seeds and crystallization temperature on the removal of organics from Bayer liquor has been investigated, and the phase composition of concentrated residue was analyzed. The experiment results showed that at the crystallization conditions of alkali concentration of 360 g/L,temperature of 60 ℃, the seeds amount of 40 g/L and crystallization time of 12 h,the removal rate of sodium oxalate was 27.40%, and the removal rate of total organic carbon was 25. 74%. Crystal morphology of concentrated residue was agglomerates and the concentrated residue were composed of organics, such as esters, acids, ketones, etc. with different composition and structure.