Extraction of Nitric Acid from Wet-process Phosphoric Acid

Abstract

Solvent extraction of nitrates (almost all as nitric acid) from WPA produced by decomposing phosphate rock with nitric acid has been investigated using four different extractants (tributyl phosphate, methyl isobutyl ketone, n-octanol and tri-n-octyl amine) in kerosene. The results show that tri-n-octyl amine (TOA) is an effective extractant for the extraction of nitric acid from the WPA. Optimum conditions for the extraction process have also been determined. The results indicate that TOA has a good ability to extract nitric acid, while only a small amount of phosphoric acid is co-extracted. TOA can be used as an effective extractant to separate nitric acid from the WPA to produce phosphoric acid. The effect of the main impurities existing in the WPA produced by nitric acid dissolution of phosphate ore (Ca

Efficient solvent extraction of phosphoric acid with dibutyl sulfoxide

“…20 SO 4 2concentration in the aqueous phase was determined by barium sulfate turbidimetry using UV-visible spectrophotometer (RSD = 3.18%). 21 The impurities concentration in organic phase were calculated by mass material balance. Each sample was analyzed at least three times and the average value was taken.…”

“…Aqueous F ‐ concentration was determined by fluorine ion selective electrode method using an ion meter (RSD = 1.80%) . SO 4 2‐ concentration in the aqueous phase was determined by barium sulfate turbidimetry using UV–visible spectrophotometer (RSD = 3.18%) . The impurities concentration in organic phase were calculated by mass material balance.…”

Liquid–Liquid Equilibria of the System Nitric Acid + Phosphoric Acid + Calcium Nitrate + Water + Tri-n-Octylamine at 298.15 K

“…Procedure and Analytical Methods. All experiments were performed in a water bath thermostatic oscillator (Shanghai Bingyue Electronic Instrument Co., Ltd., SHZ-A, Shanghai, China) at 298.15 ± 0.01 K. After deep decalcification, according to the content of each main component in the acidolysis product, 17,18 the concentrations (mass percentage ω, the same below) of nitric acid, phosphoric acid, and calcium nitrate in the initial aqueous phase were set as 5−35, 5−30 and 0.5−3%, with intervals of 5, 5, and 0.5%, respectively. The remaining component was water.…”

“…Ahmed et al 16 investigated the purification of WPA with mixtures of methyl isobutyl ketone (MIBK) and TBP. Jia et al 17 investigated the solvent extraction of nitric acid from WPA using four different extractants (TBP, MIBK, n-octanol, and TOA) in kerosene. To provide theoretical guidance for the extraction process, LLE data are necessary.…”

Ultrasound-assisted Extraction of Fe (III) from Wet-process Phosphoric Acid

“…High purity phosphoric acid is usually used in food additives, detergents, electronic grade phosphates and other high value-added fine chemical products. Thus, WPA has to be further purified in order to extend its application fields [2][3][4]. Ferric iron is one of the most troublesome impurities, and it can increase the viscosity of the WPA, thus decreasing its quality.…”