Treatment of Crude Phosphoric Acid from Some Undesirable Impurities
M.M. FawzyN.M. Farag, Alaa S. Amin, M.S. Elmaghrby
Abstract:
Organic matter contained in wet process phosphoric acid (WPPA) usually interacts with organic solvents and forms stable foams, as well as third layer those prevent phase settling and other separation problems. Hence, removal of these organics seems to be an important step for the production of decontaminated phosphoric acid and successful recovery of undesirable elements. Removal of organic matter from crude phosphoric acid was carried out by adsorption using Kaolin and Ball clay minerals. The different factors affecting the adsorption process were investigated. Under the optimum conditions the results show that, the adsorption process is applicable for the high strength and diluted phosphoric acid. Ball clay was more effective than Kaolin clay in the removal of organic matter as the adsorption efficiency was 53.6 & 39% respectively. The kinetic models were applied to the adsorption rate data and the results indicate that, the process was found to obey pseudo second order rate model. The recovery of 84.7%U and 87.8% ΣREE from the WPPA was obtained using di-nonyl phenyl phosphoric acid (DNPPA) alone in kerosene under desirable conditions, and the stripping of 93.7 and 88.2% of U and ΣREE respectively was achieved by carbonate solution.