醇酮废水硝酸氧化液分离己二酸的工艺研究

Process for Separating Adipic Acid from Nitric Acid Oxidation Solution of Cyclohexanol-Cyclohexanone Production Wastewater

研究了从以醇酮废水为原料生产混合二元酸的硝酸氧化液中分离已二酸的工艺过程和操作条件，采用结晶-活性炭脱色-重结晶的方法，先由醇酮废水硝酸氧化液中结晶分离出粗己二酸，再对粗己二酸进行脱色、重结晶，干燥得到精己二酸。己二酸的结晶条件：结晶时间180min、结晶终温不低于35℃；粗己二酸活性炭脱色条件：脱色温度75℃、活性炭加入量为粗己二酸的8％、脱色时间90min。分离出的己二酸与混合二元酸的质量比为1：2，己二酸产品的纯度为99％以上、熔点151～152℃、Pt—Co色号小于50。

The technological process and operating conditions for separating adipic acid from nitric acid oxidation solution in production of mixed diprotic acid from cyclohexanol-cyclohexanone production wastewater were studied. Via crystallization, activated carbon decoloration and recrystallization, crude adipic acid was crystallized and separated from the oxidation solution, and refined adipic acid was obtained from crude adipic acid via decoloration, recrystallization and drying. The conditions for crystallization of adipic acid are as follows ：crystallization time 180 min ,final crystallization temperature more than 35℃. The conditions for activated carbon decoloration of crude adipic acid are as follows： decoloration temperature 75 ℃, activated carbon dosage 8% of the mass of crude adipic acid ,decoloration time 90 min. The mass ratio of adipic acid to mixed diprotic acid is 1 ： 2. The product of adipic acid is characterized by purity ov.er 99% ,melting point 151 -152℃ and Pt-Co colority less than 50.