The green manufacturing process for chromium compounds

which was proposed by the Institute of Process Engineering

Chinese Academy of Sciences

has spawned a lot of interests in the chromate production industry all over the world. The separation of the intermediate product K2CrO4 is one of the bottleneck units in the green manufacturing process. This work is to seek a new approach to the separation of K2CrO4. The solubility data of K2CrO4 in the K2CrO4-KOH-H2O system were regressed and processed. The possibility of separating K2CrO4 from the K2CrO4-KOH-H2O system through salting-out crystallization with a salting-out reagent was investigated. The kinetic relationship between the maximum supersaturation and supersaturation rate during nucleation was obtained.The relationship among the concentration of the salting-out reagent

the recovery efficiency of K2CrO4 and the solution volume of the final system was also obtained. The feasibility of the separation of K2CrO4 from the K2CrO4-KOH-H2O system through salting-out crystallization with KOH as the salting-out reagent was explored.This method provides a promising approach to the highly efficient separation of K2CrO4.