The mixing-precipitation process for producing phenylpyruvic acid sodium salt(PPNa) by neutralization of phenylpyruic acid(PPA) with aqueous sodium hydroxide in a semi-batch stirred tank was studied.The effects of mixing characteristics and chemical characteristics on the precipitation process were investigated experimentally.It was found that the crystals growth rate and morphology obviously changed due to ripening.Crystal redissolution agglomeration and solvent inclusion also changed the purity of PPNa product considerably.
