Purification Of Phosphoric Acid Research Articles

Development of Novel and Cost Effective Techniques for Purification of Commercial Grade Phosphoric Acid for Fertilizers, Food and Pharmaceutical Industries

AbstractCultivation of 1.5 millions Faddens is one of the major projects for securing food supply to the ever increasing population; therefore, expansion of the fertilizer industry becomes a must.Phosphate ores from New Valley and Nile Valley are chemically processed by sulphuric acid to produce phosphoric acid intermediate by the dihydrate process. Two plants are already inoperation at “Abu Zabaal” and “Fayoum” and another two plants are under establishment, onealong the Red Sea Coast at El-Sokhna and the other at the “New Valley”. Two major problems are facing the industry, namely, the low filtration rate of the acid from solid gypsum and the second is the high level of impurities which decreases the P2O5 water solubility of the produced fertilizers. The filtration rate has been doubled by utilization of surface active agents(Surfactants) to modify the gypsum crystals. On the other hand, novel technique is being developed to decrease the impurities especially iron from 4% to < 1% leading to increasing the P2O5 water solubility of the produced fertilizer. Further decrease of Fe content of the fertilizer grade acid to < 0.1% is achieved through application of a novel membrane technology. The purified acid could be used for food and pharmaceutical industries, thus the economics of the acid production units greatly improve. The paper reviewed the results obtained so far which will improve significantly the value added products. The effects of the different parameters such as oxalic acid dose, temperature and concentration of phosphoric acid on Fe2O3 removal efficiencyhave been studied. Increasing the oxalic acid dose up to 7.5 g/100g of 28% P2O5 (80oC, 100 rpm) raised the removal efficiency of Fe2O3 to 90.8%. Increasing the dose of oxalic acid to 10 g/100g led to slight increase in the removal efficiency of Fe2O3 to 91.6%.

Purification of Crude Phosphoric Acid and Leached Apatite by Solvent Extraction with CYANEX 923 in Kerosene

CYANEX 923 (a mixture of four trialkylphosphine oxides) in kerosene has been used for the extraction of phosphoric acid. Different parameters affecting the extraction of phosphoric acid such as shaking time, temperature, phase ratio O/A, extractant and phosphoric acid concentration were separately investigated. The stoichiometry of the extracted species was found to be H3PO4.L, where L refers to CYANEX 923. The stripping of the extracted species was found to be efficient with water. The obtained results were used for the recovery of phosphoric acid from both the crude acid and the leached solution from digestion of apatite phosphate rock with hydrochloric acid. Expanded Perlite was found to be efficient for the adsorption of uranium from both crude acid and the leached apatite.

A polysulfone-based anion exchange membrane for phosphoric acid concentration and purification by electro-electrodialysis

A series of quaternary ammonium polysulfone (QAPSU) anion exchange membranes used the chlorotrimethylsilane instead of toxic chloromethyl methyl ether and quaternized-functionalized by trimethylamine ethanol solution were prepared. The effect of chloromethylation reaction time on membrane morphologies and physiochemical properties such as ion exchange capacity, water swelling, and membrane area resistance, mechanical and thermal stabilities was investigated. When being applied in electro-electrodialysis (EED) for purifying phosphoric acid solution, the QAPSU membranes exhibit high purification efficiency, especially all the metal ions (Fe, Mg, Ca) removal rates reach over 60%, which suggests that the QAPSU membranes have a high potential for EED application.

PROBLEMS AND PROSPECTS OF PRODUCTION AND QUALIFICATION OF PHOSPHORIC ACID

The qualification of phosphoric acid is carried out depending on the use of phosphates of various deposits and the necessary quality of the final products. An acquisition of phosphoric acid of the required quality should be carried out taking into account three aspects: resource-energy, ecology and complex processing. Solving the problems of one aspect entails solving the problems of the other aspects. The rational use of natural resources and the reduction of environmental pollution is the determining factor in the choice of technological regimes for complex processing of raw materials with a reduction in the volume of waste of all kinds or transferring them into forms easily recyclable or specially stored. The absence of economically sound technologies for processing phosphogypsum determines its preferential warehousing. The second component that requires recycling is fluorine. In this regard, the purification of phosphoric acid from fluorine should use technologies that realize the trapping of fluorine compounds released into the gas phase. This is relevant from the point of view of the complexity of processing raw materials with the extraction of rare-earth elements. The use of mechanochemical activation makes it possible to achieve a nanoscale level. To a lesser extent, this aspect relates to the stage of sulfuric acid decomposition, proceeding with the participation of three phases: solid, liquid and gas. In turn, the surface structure of the gas-liquid layer plays the role of an energy barrier for evaporation. To establish the basic energy patterns of concentration and defluorination n the disc apparatus and to optimize the process, a thermophysical model was developed in which the range of effective parameters was determined by the joint solution of a number of equations for the desired ingredients in the phosphoric acid concentration range of 52-65%. The solution of the problem of complex purification of wet-process phosphoric acid can be carried out by adsorption methods that allow to remove to some extent almost all impurities.For citation:Smirnov N.N., Smirnova D.N., Ilyin A.P., Kochetkov S.P. Problems and prospects of production and qualification of phosphoric acid. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 7. P. 48-56.

Regulatory Framework for the Decommissioning of Indonesian Nuclear Facilities

The decommissioning of nuclear facilities in Indonesia are mainly based on Nuclear Energy Act of 1997 on, Nuclear Energy Regulatory Agency (BAPETEN) Chairman Regulation (BCR) No. 4 of 2009, and Government Regulation (GR) No. 2 of 2014 that cover general provisions and licensing requirements of decommissioning and the detailed requirements and guidelines for preparing the decommissioning plan and licensee applications. BCR No. 4 of 2009 was developed based on the adoption and adaption from the International Atomic Energy Agency (IAEA) Safety Guide, WS-G-2.1. Currently, one of three research reactors, Training Research Isotopes General Atomics (TRIGA) research reactor 2 MW (the oldest which went critical at 250 kW in 1964, and was operated at maximum in 1971, and was upgraded to 2 MW in 2000), has operated for 45 y, but there is no decision for decommissioning this reactor yet. Indonesia has experience in decommissioning of the phosphoric acid purification facility of the Gresik petrochemical plant. Some aspects of decommissioning, which have been successfully addressed to date, are: regulation, communication, and decommissioning team. Development of human resources, technological capability, and information flow from more advanced countries are an important factor for the future of the nuclear facility decommissioning plan in Indonesia. Some regulations have still not anticipated all the regulatory challenges that might be encountered in the near future. More regulations and guidance are needed to be established by BAPETEN in order to complete the current regulations so that problems can all be anticipated.

Wet process of phosphoric acid purification by solvent extraction using tri-n-butyl phosphate and cyclohexanol mixtures

Solvent extraction is an efficient, economical and widely-used technology for the purification of wet process phosphoric acid (WPA). This present work focused on the development of a solvent extraction system, TC, representing tri-n-butyl phosphate (TBP) and cyclohexanol mixtures. The equilibrium phase diagram of the system H3PO4?H2O?TC at 298.2 K and atmospheric pressure was obtained. The effects of extraction time, phosphoric acid concentration, extractant concentration, temperature and phase volume ratio on extraction efficiency were studied. The extracted complexes were estimated to be 1.8H3PO4 2TC. The extraction process of H3PO4 was exothermic and the enthalpy change, ?H, was obtained. The solvent mixtures had a high efficiency for phosphoric acid purification via multi-stage counter-current extraction from the industrial WPA in a reciprocating plate extraction column with an H3PO4 extraction yield of 85.08 % at 313.2 K. The stability, extraction efficiency and recycling capability of TC for H3PO4 extraction were also estimated.

Purification of Wet Process Phosphoric Acid by Solvent Extraction using Cyclohexanol

Purification of Wet Process Phosphoric Acid by Solvent Extraction using Cyclohexanol

Occupational radiation dose estimation over radioactive waste of phosphoric acid purification and ore products projects

Occupational radiation dose estimation over radioactive waste of phosphoric acid purification and ore products projects

Liquid–Liquid Equilibrium Data of Extraction with Tri-n-butyl Phosphate on Phosphoric Acid Containing Sodium Sulfate or Potassium Sulfate

Wet-process phosphoric acid is developed with the lack of a quality mineral. More and more research focuses on the purification of wet-process phosphoric acid with solvent extraction method. Liquid–liquid equilibrium data are of important significance in the industrial reality. In this work, equilibria data have been obtained for the two quaternary systems phosphoric acid–sodium sulfate–water–tri-n-butyl phosphate and phosphoric acid–potassium sulfate–water–tri-n-butyl phosphate, which contain concentrations of components and densities and viscosities of the equilibrium phases, and also the varieties of distribution coefficient of phosphoric acid are analyzed. In different systems (phosphoric acid solution with sodium sulfate or potassium sulfate at 303.2 K), the distribution coefficient of phosphoric acid with sodium was found to be higher than that of potassium ion, which demonstrates that the extraction of phosphoric acid with sodium is greater than that with potassium ion. In addition, NRTL model and ...

One Stage Solvent Extraction Synergism for the Purification of Industrial Wet Process Phosphoric Acid to the Food Grade Quality

One Stage Solvent Extraction Synergism for the Purification of Industrial Wet Process Phosphoric Acid to the Food Grade Quality

Potentiality of Alcoholic Purification of Abu-Zaabal Impure Phosphoric Acid for Selective Ion Exchange Recovery of Uranium

Potentiality of Alcoholic Purification of Abu-Zaabal Impure Phosphoric Acid for Selective Ion Exchange Recovery of Uranium

Potentiality of Alcoholic Purification of Abu-Zaabal Impure Phosphoric Acid for Selective Ion Exchange Recovery of Uranium

A suggested procedure was studied for recovering of uranium selectively from the Abu Zaabal impure phosphoric acid assaying about 46% P2O5 and about 3% iron. This procedure involves the application of an alcoholic precipitation step for most impurities by using isopropyl alcohol and cationic resin where uranium was kept in the acid phase by a prior oxidation step. After distillation of alcohol for recycling, the uranium in the purified phosphoric acid was properly reduced to U+4 and recovered via the Chinese cation exchange resin namely; amino phosphonic (D4O4). Displacing Fe+2 from the resin, washing the resin with aqueous ammonia, eluting the resin with carbonate – bicarbonate solution and precipitating uranium from the elute as UO3-2H2O.

Purification of industrial phosphoric acid (54%) using Fe-pillared bentonite.

The current problem of excess impurities in industrial phosphoric acid (IPA) 54% P2O5 makes phosphates industries look toward low-cost but efficient adsorbents. In the present study, iron-oxide-modified bentonite (Fe-PILB) was prepared and investigated as a possible adsorbent for the removal of organic matter (OM) like humic acid (HA), chromium (Cr(III)), and zinc (Zn(II)) from IPA aqueous solutions. These adsorbents were characterized using XRD, TEM, and BET. The adsorption of impurities is well described by the pseudo-second-order model. The results indicate that Fe-PILB has a good ability to resist co-existing anions and the low-pH condition of IPA and owns a relatively high-removal capacity of 80.42 and 25% for OM, Cr(III), and Zn(II). The mechanism of adsorption may be described by the ligand and ion exchange that happened on the active sites. The selected order of adsorption OM > Cr(3+) > Zn(2+) showed the importance of the competitive phenomenon onto bentonite materials' pore adsorption. For the adsorption of OM at the low pH of IPA, H-bond complexation was the dominant mechanism. From the adsorption of heavy metals and OM complex compounds contained in IPA 54% on Fe-PILB, the bridging of humic acid between bentonite and heavy metals (Zn(II) or Cr(III)) is proposed as the dominant adsorption mechanism (bentonite-HA-Me). Overall, the results obtained in this study indicate Fe-pillared bentonite possesses a potential for the practical application of impurity (OM, Zn(II), and Cr(III)) removal from IPA aqueous solutions.

Performances of nanofiltration on industrial phosphoric acid purification

Phosphoric acid production is of major importance to the Tunisian economy. However, the quality produced is not suitable for other than agricultural use due to mineral and organic impurities. In this study, the purification of industrial phosphoric acid with a maximum P2O5 concentration of 25% was achieved by nanofiltration. Six solutions of different P2O5 concentration were used. The removal of organic (total carbon) and inorganic impurities such as magnesium, iron, chrome, zinc, cadmium and vanadium, were studied.The performances of nanofiltration (NF) Nadir NP 30 membrane were determined in terms of permeate flux and P2O5 and impurities retention taking into account the effect of transmembrane pressure, P2O5 concentration and membrane prea-treatment by purified phosphoric acid solution.Results showed that for the industrial 25% P2O5 acid solution, the use of NF membrane achieved a retention of 87.35%, 86.73%, 87.57%, 78.41% and 73.17%, respectively, for iron, aluminum, chrome, magnesium, vanadium and organic matter (kerogen and humic acids) under a pressure of 20 bar. P2O5 permeation increased with the increase of its concentration in the acidic feed solution. The best permeation is provided by 25% P2O5 feeding acid solution which is of almost 98%.

Novel Technique for Purification of Fertilizer Phosphoric Acid with Simultaneous Uranium Extraction

A process codenamed PHOSPURIN is described for the purification of Fert Phosphoric acid with simultaneous extraction of Uranium compounds from acid. This includes maintaining the acid stream at different redox potentials for the necessary extraction of all the metals & rare earths using Solvent Extraction technique. Details are also provided on the extraction behavior of various cations and rare earths from fert acid media employing redeveloped Phosphate reagent (codenamed KROPHOS-18) in kerosene system.The effects of various parameters, such as the concentration of acid, metal ion and extractant, nature of the diluents etc., on the extraction of various cations have been investigated. Based on the extraction data, most of the cations like Fe (II) & (III), Al, Mg, Ca, Mn, Na, K, heavy metals like Arsenic / Cadmium, rare earths including Uranium etc., are all being extracted with high to very high separation factors from all molar fertilizer phosphoric acids.The practical utility of the extractant & the process has been demonstrated by tests on commercial fert phosphoric acid. It has been conclusively found that KROPHOS-18 has good properties, such as high distribution coefficient, good stability, acceptable kinetics, good phase separation etc.

Preparation and Research Advance of Electronic Grade Phosphoric Acid

The application of high purity phosphoric acid in industrial production is more and more widely used, especially electronic grade phosphoric acid, and the demand of it has risen year by year. This paper introduces the preparation and research advance of electronic grade phosphoric acid, expounds the principle, advantages and disadvantages and research advance of preparing high purity phosphoric acid by high purity phosphorus oxidation method and phosphoric acid purification method. Using hot process by direct method to prepare high purity electronic grade phosphoric acid is still the mainstream on the current, and the key of technique is the purification of yellow phosphorus and phosphoric acid.

Electrodialysis of Phosphates in Industrial-Grade Phosphoric Acid

The objective of this research was to study the purification of industrial-grade phosphoric acid (P2O5) by conventional electrodialysis. The experiments were conducted using a three-compartment cell with anion and cation membranes, and industrial acid solution was introduced into the central compartment. The elemental analysis of the diluted solution indicated that the composition of magnesium, phosphates, and sodium was reduced in the central compartment. The ratios of the concentration of the ions and the phosphates were essentially unchanged by the process. Consequently, electrodialysis could not purify the acid in the central compartment, and the migration of phosphate ions to the anolyte produced a highly concentrated phosphoric acid solution containing sulfates and chlorides as impurities. However, the migration of the phosphate ions across the membrane consumed a large amount of energy. Detailed speciation diagrams were constructed in this study. These diagrams showed that metal-phosphate complexes were predominant in the industrial phosphoric acid solution. This result explains why the ratios of the concentrations of the ion metals and the phosphates did not change in the purification process. The energy consumed in the electrodialysis indicated that the metal-phosphate complexes were less mobile than the free-phosphate ions. The speciation diagrams explained the experimental results satisfactorily.

Aminotrimethylene Phosphonic Acid and Sodium Ethyl Xanthate for Purification of Stripped Phosphoric Acid Produced from Commercial Acid by Solvent Extraction

. It was used as a raw material for the production of detergents, food products, and alimentary supplies for cattle, toothpastes and fertilizers. High grade phosphoric acid was obtained using liquid-liquid extraction with aliphatic alcohols to separate metal and fluoride ion impurities in the aqueous phase. The influence of alcohol concentration, organic/aqueous phase ratio, temperature, shaking time and phosphoric acid concentration on P

Wet process phosphoric acid purification by solvent extraction using N‐octanol and tributylphosphate mixtures

AbstractBACKGROUNDSolvent extraction using organic extractants is an important technology for purifying wet process phosphoric acid. The purification of the wet process phosphoric acid by liquid–liquid extraction using solvent mixtures of N‐octanol and tributylphosphate has been investigated.RESULTSThe purification process comprised extraction, scrubbing and stripping operations. The extraction conditions, i.e. shaking time, temperature, composition of solvent mixtures and P2O5 concentration for purification of the wet process phosphoric acid were studied. The phase diagram of the pseudo‐ternary system H3PO4‐H2O‐solvent mixtures at 313.15 K was determined. The McCabe–Thiele diagram showed that three counter‐current stages achieved about 91 wt% P2O5 extraction at 313.15 K. Scrubbing and stripping operations using pure phosphoric acid with 10 wt% P2O5 and doubly distilled water, respectively, were studied.CONCLUSIONSThe phosphoric acid finally produced was found to be high grade which met the special requirements of the user. Optimization of the extraction conditions and system was capable of providing academic and technical foundations to realize industrial production. © 2012 Society of Chemical Industry

Modeling of phosphoric acid purification contaminated by magnesium and cadmium

The present study brings to light modeling of the purification of phosphoric acid, which is obtained through the wet process route. The said wet process inevitably is used to remove the impurities, mainly the heavy metal cations such as Mg2+, Cd2+, etc., which are initially present in the phosphate rocks and it is imperative that these impurities be removed . For the very same purpose, liquid–liquid extraction has proven to be one of the most reliable techniques and hence it is again considered, basing the model on the purely theoretical considerations of thermodynamics and mass transfer. The developed model was tested on two systems with Mg2+and Cd2+ as the contaminants and dinonylnaphthalene sulfonic acid and di (2-ethylhexyl) dithiophosphoric acid as complexing agents, both diluted in kerosene and dodecane, respectively. A parametric study was carried out, to investigate the effect of certain key parameters such as the phosphoric acid and the extractant initial concentrations.