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Removal of organic matter from crude wet‐process phosphoric acid
Author(s) -
Hanna A. A.,
Ali A. F.
Publication year - 1992
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.280550302
Subject(s) - phosphoric acid , charcoal , chemistry , organic matter , adsorption , organic acid , activated charcoal , dilution , nuclear chemistry , chromatography , organic chemistry , physics , thermodynamics
The organic matter was removed from the crude wet‐process phosphoric acid, produced by treating the Egyptian phosphate ore with sulphuric acid, using fine powder charcoal. The optimum charcoal/acid weight ratio, the effect of the acid concentration and the temperature on the efficiency of removal were studied. It is found that the percentage of the organic matter content decreases from 2·172 × 10 −2 , for the crude phosphoric acid, to 0.108 × 10 −2 after treatment of 70 g acid with 600 mg fine powder charcoal. When the charcoal/crude acid weight ratio reaches 1%, the crude acid becomes free from the organic matter and its colour turns from dark‐brown into pale‐green. This green colour is due to the presence of Fe 2+ ions. Also, it is found that as the acid concentration decreases, the efficiency of the charcoal in removing organic matter increases. This may be due to the decrease of the acid viscosity, by dilution, which enables the charcoal particles to spread and penetrate more easily through the medium. The results of the effect of temperature show that the efficiency of charcoal in removing organic matter increases as the temperature is raised. This increase is also attributed to an increase in the charcoal apparent activity due to the decrease in the acid viscosity with temperature, leading to less possibility of scaling and more net surface area available for adsorption.