M. Feki et Hf. Ayedi, Purification of wet process phosphoric acid by solvent extraction with methyl isobutyl ketone: Systematic study of impurity distribution, SEP SCI TEC, 33(16), 1998, pp. 2609-2622
This paper reports a study on the purification behavior of methyl isobutyl
ketone (MIBK) for the major impurities of the phosphoric acid wet process (
Ca2+, Mg2+, Al3+, Fe3+, SO42-, and F-). Distribution coefficients of phosph
oric acid (PA) and impurities, as well as selectivity of MIBK for PA, have
been studied as a function of the PA concentration (wt%) in the organic pha
se. Our results are compared to those obtained with other solvents (isoamyl
alcohol, dibutyl ether, and dipropyl ether) described in the literature. M
IBK seems to have the best selectivity far PA against SO42-, and it shows a
n intermediate behavior between those of isomyl alcohol and ethers with reg
ard to metallic impurities.