Disclosed is a process to produce a dry purified carboxylic acid product comprising furan-2,5-dicarboxylic acid (FDCA). The process comprises oxidizing at least one oxidizable compound selected from the following group: 5-(hydroxymethyl)furfural (5-HMF), 5-HMF esters (5-R(CO)OCH2-furfural where R is alkyl, cycloalkyl, or aryl), 5-HMF ethers (5-R′OCH2-furfural where R′ is alkyl, cycloalkyl, or aryl), 5-alkyl furfurals (5-R″-furfural where R″ is alkyl, cycloalkyl, or aryl), mixed feedstocks of 5-HMF and 5-HMF esters, mixed feedstocks of 5-HMF and 5-HMF ethers, and mixed feedstocks of 5-HMF and 5-alkyl furfurals to generate a crude carboxylic acid slurry comprising FDCA.