Utilization of Fenton oxidation approach in wet phosphoric acid process for mitigating foam generation

Significant amounts of foam generated during the production of phosphoric acid would severely occupy the head space in the reactors, thereby reducing output capacity dramatically. Here, we first proposed a green and clean approach based on Fenton oxidation theory to mitigate the generation of foam. The effect of H2O2 dosage, FeSO4 dosage, and pH value on the defoaming performance were investigated systematically. Moreover, the defoaming performance between Fenton oxidation process and traditional defoamer were compared and the defoaming mechanism was described with the help of XRD analyses. The results obtained from the Fenton oxidation process demonstrate that the use of H2O2 in conjunction with FeSO4 are beneficial to mitigating the foam generation, and the defoaming performance is positively correlated to the dosage. Furthermore, Fenton oxidation process outperforms than that of traditional defoamer in terms of reducing foam generation. The defoaming mechanism is ascribed to the fact that the organic substrates existing on the phosphate concentrate surface could be completely decomposed and the soluble carbonate minerals were prone to being dissolved during the regulation of pH value, thereby inhibiting the production of CO2 gas. This work is helpful in providing guidance for utilizing a green and clean approach based on advanced oxidation theory to mitigate the foam generation during the wet phosphoric acid process. More importantly, it provides a theoretical basis for optimizing this type of processing methods.