The influence of the chemical composition of phosphorites from southern Israel on foaming during acidification

Phosphorites are important natural resources and are the main source for the production of phosphoric acid and phosphorous fertilizers. The reaction of phosphate rock with acid is the most common process to produce phosphoric acid. However, this process may result in the formation of foam, which reduces the efficiency of the industrial production process. In the present study, phosphorite samples from various phosphate basins in southern Israel were analyzed for their major chemical constituents and impurities in order to investigate their possible effect on foam formation and stability. Results of this study indicate that while the foam volume depends on CaCO₃ content in the phosphorite, the foam stability is affected by the composition of organic matter. UV–vis spectroscopic characterization of the humic substances in phosphorite's organic matter showed that foam stability increases when humic substances have a more fulvic–like structure. The results of the study indicate a possible synergistic effect between metal ions and humic substances on foam stability.