Extraction Of Mineral Acids Research Articles

Molecular thermodynamic model for solvent extraction of mineral acids by tri-n-butyl phosphate (TBP)

Removal or recovery of acids by solvent extraction is highly relevant for recycling, process control, and wastewater decontamination, especially in the hydrometallurgical industry. The construction and optimization of such processes would benefit from a molecular thermodynamic model that can predict liquid–liquid equilibria. Past attempts resulted in models that were not very predictive. Therefore, a new approach was followed and demonstrated for the extraction of the mineral acids (inorganic acids) HNO3, HCl, H2SO4, H3PO4, and H3AsO4 by tri–n–butyl phosphate (TBP). The semi-empirical OLI Mixed-Solvent Electrolyte (MSE) framework was used to construct the thermodynamic model for calculating the liquid–liquid equilibria. Contrary to previous attempts, this framework allows the description of both the aqueous and organic phases in one model, and it can accurately deal with the non-ideal behavior of concentrated electrolyte solutions. The best agreement between calculated and experimental distribution data was achieved by assuming that the extraction of mineral acids occurs via protonation of TBP and coextraction of the anions. At very high acid concentrations, also neutral acid molecules are transferred to the organic phase. The high accuracy of the thermodynamic model for all mineral acid systems considered in this study is an indication that this approach for modeling liquid–liquid equilibria is a universal one. Furthermore, the extraction of mineral acids can be predicted in mixed-acid systems and acid-salt systems that were not used to construct the model.

Third phase formation behaviour of tris(2-methylbutyl) phosphate and tri-n-alkyl phosphates in the extraction of mineral acids and tetravalent metal ions

Abstract The formation of third phase is a detrimental phenomenon witnessed in the nuclear separation processes during the extraction of certain metal salts by an organic solution, which comprises of a neutral extractant, tri-n-butyl phosphate dispersed in a non-polar diluent, n-dodecane (n-C12H26). In the present work, a comparative analysis on the third phase formation behaviour of three trialkyl phosphates, TBP, its linear and branched higher homologues tri-n-amyl phosphate and tris(2-methylbutyl) phosphate (T2MBP), respectively, have been provided which will be useful for the identification of an extractant with minimum third phase formation tendency. The organic phase splitting behaviour during the extraction of three mineral acids (HClO4, HCl and HNO3) and two tetravalent metal nitrates (Th(IV) and Zr(IV)) by trialkyl phosphates has been investigated to understand the influence of anionic and cationic components, respectively, in third phase formation of trialkyl phosphates. The effect of structure of the alkyl groups of trialkyl phosphate and chain length of diluents on third phase formation during Zr(IV) extraction from HNO3 media have also been studied. Overall, the third phase formation behaviour of T2MBP was found to be lower both for the extraction of mineral acid and Zr(IV), thereby indicating its potentiality for applications in various solvent extraction processes.

Effect of hydrophobic ionic liquids aqueous solubility on metal extraction from hydrochloric acid media: Mathematical modelling and trivalent thallium behavior

A mathematical model to explain cations’ solubility of both protic and aprotic ionic liquids in a wide range of hydrochloric acid solutions has been developed. The concept of this model is based on an assumption of the mineral acid extraction into the organic phase, formation of a salt there between an ionic liquid cation and chloride-anion due to ions recombination and partial salt back-extraction. The proposed approach allows estimating corresponding extraction constants. Comparison of calculated and experimentally measured solubility product constants shows that they are in good agreement. It has been determined also that the more the hydrophilicity of the ionic liquids’ cation the more hydrochloric acid is extracted. This model has been utilized to facilitate analysis of thallium transfer into hydrophobic ionic liquids providing insights into the mechanism of metal extraction.

Investigation of a novel ionic liquid, Cyphos IL 104 for the solvent extraction of mineral acids

A variety of mineral acids is used in metallurgical processes which generate a huge amount of waste solutions containing such acids. Effective recovery of these acids can yield value added products which can minimize health and environmental hazards. The present investigation deals with the use of an ionic liquid as an extractant for the recovery of mineral acids. Extraction behavior of an equimolar concentration (1M) of different mineral acids such as HCl, H2SO4, H3PO4, HClO4 and HNO3 was investigated using an ionic liquid, “Cyphos IL 104” (trihexyl(tetradecyl) phosphonium bis(2,4,4-trimethylpentyl) phosphinate) ([R4P+][A−]). The stoichiometry of extraction of the acid by the ionic liquid examined by Job's method indicated the involvement of 1mol of Cyphos IL 104 for the extraction of 1mol of acid. Loading capacity of Cyphos IL 104 for different acids was particularly investigated. McCabe Thiele plots drawn for the extraction of HCl and HNO3 by using 0.5M Cyphos IL 104 indicated that two stages are required for complete extraction of 1M HCl at O/A ratio of 2.2:1, whereas only one stage is required for complete extraction of 1M HNO3 at O/A ratio of 2:1. Stripping study of loaded Cyphos IL 104 was examined using distilled water and NaOH solution. Regenerated Cyphos IL 104 exhibited similar extraction efficiency as that of virgin Cyphos IL 104. Extraction of hydrochloric acid by Cyphos IL 104 has also been studied in the presence of the lanthanum (III) ions with the aim of processing the leach solutions of rare earths containing resources.

Extraction of mineral acids and lanthanum salts with binary extractants

Extraction of mineral acids with methyltrioctylammonium dialkylphosphinate was studied, and the extraction ability of acids was shown to decrease in the series HNO3 ≫ HBr > HCl, which corresponds to anion-exchange series for the initial salts of quaternary ammonium bases (QAB). Extraction of lanthanum bromide with methyltrioctylammonium dialkylphosphinate was studied, the composition of extracted compounds was established, and extraction constants were calculated. The extraction ability of dinonylnaphthalenesulfonate was found to be considerably lower than that of QAB dialkylphosphinate because of a larger value of acid dissociation constant for dinonylnaphthalenesulfonic acid. It was shown that lanthanum in systems with binary extractants can be back extracted from organic phase with dilute solutions of mineral acids.

Extraction of mineral acids with methyltrioctylammonium dinonylnaphthalenesulfonate

The interphase distribution of hydrogen halides (HF, HCl, HBr, and HI) and oxygen-containing acids (H2SO4 and HClO4) in a system with the binary extracting agent methyltrioctylammonium dinonylnaphthalenesulfonate was studied. It was found in the extraction of mineral acids depending on the aqueous acidity, that the distribution ratios of mineral anions B m− decreased with pH in accordance of the laws of binary extraction. The extraction isotherms of mineral acids were obtained, and the apparent constants of extraction were calculated.

Antinutritional factor content and hydrochloric acid extractability of minerals in pearl millet cultivars as affected by germination

Four pearl millet cultivars of two different species—Kordofani and Ugandi (Pennisetum typhoideum) and Madelkawaya and Shambat (Pennisetum glaucum)—were germinated for 6 days. The germinated grains were dried and milled. Phytic acid and polyphenol contents and hydrochloric acid (HCl) extractability of minerals from the malt flours were determined at intervals of 2 days during germination. Phytic acid and polyphenol contents decreased significantly (P≤0.01) with an increase in germination time, with a concomitant increase in HCl extractable minerals. However, the major mineral content was significantly decreased while that of trace minerals was increased with germination time. When the grains were germinated for 6 days, Madelkawaya had higher extractable calcium while Ugandi had higher extractable phosphorus, whereas iron and manganese recorded high levels in Shambat and Madelkawaya, respectively. There was good correlation between antinutritional factors reduction and the increment in extractable minerals with germination time.

Phytic acid content and hydrochloric acid extractability of minerals in pearl millet as affected by germination time and cultivar

Ten pearl millet cultivars (SOSAT C-88, ZANGO, EX-BORNO, LCRI 9701, ICMV-IS 94206, ICMV-IS 94208, GWAGWA, G.I-14.9, GB 8735, G.I-297-1) were germinated for 96 h. The germinated grains were dried, polished and milled. Phytic acid contents and hydrochloric acid (HCl) extractability of minerals from the malt flours were determined at intervals of 24 h during germination. Phytic acid content decreased significantly ( P < 0.05) with increase in germination time with concomitant increase in HCl extractable mineral contents. EX-BORNO had higher extractable Ca, while LCRI-IC 9701 had higher P, whereas Zn, Cu, Fe and I recorded high levels in ICMV-IS 94208, GB 8735, G.I-297-1 and ICMV-IS 94208, respectively. Mn did not differ ( P > 0.05) at the various levels of germination time. There was good correlation between phytic acid reduction and increase in extractable minerals with increase in germination time.

Potential bias in the isolation of pyridinic nitrogen fractions from crude oils and rock extracts using acid extraction and liquid chromatography

Simple mineral acid extraction and open column chromatographic methods commonly used to isolate pyridinic nitrogen fractions from crude oil and rock extract appear to yield severely altered distributions of alkylquinolines and benzoquinolines. This potential analytical bias, if not recognized, could lead to incorrect geochemical interpretations.

Extraction of Mineral Acids with Neutral Organophosphorus Extractants

Extraction of HNO3, HCl, H2SO4, H3PO4, H3AsO4, HF, and H2C2O4 with triisoamyl phosphate (TiAP), diisooctyl methylphosphonate (DiOMP), isoamyldialkyl(C7-C9)phosphine oxide (DRPO), and cyclohexyldialkyl(C7-C9)phosphine oxide (DRPO-1Ts) was studied, and the extraction isotherms were obtained. The solvation numbers of certain acids and extractants were determined by dilution and saturation methods. Purification of wet-process phosphoric acid to remove arsenic was studied. Distribution of Cu, Zn, Ni, Co, Fe, and Mn microamounts in the oxalic acid-neutral organophosphorus compound (NOPC) extraction systems was measured, and the feasibility of purification of oxalic acid to remove these metals to a 10-7% content was demonstrated.

The extraction of mineral acids by the phosphine oxide Cyanex 923

The distribution equilibria of mineral acids: H 2SO 4, H 3PO 4, HCI, HClO 4 and HNO 3 between aqueous solutions and organic solutions of the phosphine oxide Cyanex 923 in toluene or decane are described. Partition studies have shown that the organic diluent only slightly influences the acid extraction. The extraction mechanism can be related to the solvation of the acid and formation of the L · H m +X m−1 (m = 1, 2 or 3) species in the organic phase, where L is the extractant; only in the case of initial high HNO 33 concentrations is the formation of the L · (HNO 3) 2 species apparent in this phase. The effect of temperature on the acid extraction is also evaluated.

PH Dependence of Carboxylic and Mineral Acid Extraction by Amine-Based Extractants: Effects of pKa, Amine Basicity, and Diluent Properties

Extraction mechanism strongly depends on the acid-base properties of the extractant as well as on those of the extracted acid. For amines of basicity similar to that of the anion of the extracted acid, or higher, extraction is governed by ion-pair formation. H-bonding of undissociated acid becomes important only for extraction of weak acids by weak bases. Extraction mechanism determines the effect of various parameters. Thus the degree of extraction is most sensitive to pH at about the pK{sub a} of the amine for extraction through ion-pair formation. Extraction by H-bonding, however, is most sensitive at about the pK{sub a} of the acid. Polar and protic diluents enhance extraction through ion-pair formation, but may have no effect on H-bonding or even hinder it. Extraction through ion-pair formation prefers stronger acids at low pH while H-bonding extracts weaker acids more efficiently. Clarification of the extraction mechanism and its dependence on extracted acid properties and on the pH provide for designing extractants of high efficiency and selectivity.

In the Thermophilic Archaeon Sulfolobus solfataricus a DNA-Binding Protein Is in Vitro (Adpribosyl)Ated

A small protein with high affinity for homologous DNA was isolated from Sulfolobus solfataricus homogenate by mineral acid extraction. It was purified using a two-step procedure including CM-cellulose and RP-HPL chromatographies. The protein was electrophoretically homogeneous, had a molecular weight of 7.147 kDa and an amino acid composition with a high content of lysine and glutamic acid residues. The protein was able to protect DNA against thermal denaturation and DNAase I digestion in a dose-dependent manner. After incubation of the sulfolobal homogenate in the presence of 32P-NAD, followed by the purification steps, the protein was modified by ADPribose, as revealed by reaction product analysis, SDS-PAGE and autoradiography.

Hydrochloric acid extractability of minerals from rabadi - a wheat flour fermented food

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydrochloric acid extractability of minerals from rabadi - a wheat flour fermented foodManju. Gupta and Neelam. KhetarpaulCite this: J. Agric. Food Chem. 1993, 41, 1, 125–127Publication Date (Print):January 1, 1993Publication History Published online1 May 2002Published inissue 1 January 1993https://doi.org/10.1021/jf00025a027RIGHTS & PERMISSIONSArticle Views51Altmetric-Citations4LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (365 KB) Get e-Alerts Get e-Alerts

RECOVERY AND CONCENTRATION OF STRONG MINERAL ACIDS FROM DILUTE SOLUTIONS THROUGH LLX. I: REVIEW OF PARAMETERS FOR ADJUSTING EXTRACTANT PROPERT AND ANALYSIS OF PROCESS OPTIONS

ABSTRACT Parameters affecting extraction power of amine-based extractants for mineral acids are reviewed. Means for adjusting extractant composition for reversible extraction of mineral acids from dilute solutions are discussed. The paper also analyses process options for recovery of the extracted acid at concentrations higher than those in the original solution. Introduction of the required energy as thermal energy without resorting to evaporation of the acid or to evaporation of water is highly attractive.

DILUENT EFFECTS IN SOLVENT EXTRACTION

ABSTRACT The empirical diluent parameters DP, introduced by Shmidt et al. several years ago, describe the extraction of mineral acids or metal complexes by the expression log Kex = log Kex ° + const. DP. They have now been related to independently obtainable properties of the diluents. The best correlation is with Dimroth and Reichardt's polarity index ET, with Hildebrand's solubility parameter δ as an additional parameter causing some improvement. The new expression is: log Kex = log Kex ° + const1. ET + const2. δ.

Evaluation of methods based on acid extraction and atomic absorption spectrometry for multi-element determinations in rivers sidements

A method for the multi-element determination of major, minor and trace metals in sediments by mineral acid extraction (HNO 3/HCl) and atomic absorption spectrometry (a.a.s.) is evaluated with the use of NBS SRM-1645 and applied in the analysis of river sediments. The elements Li, Na, K, Rb, Mg, Ca, Sr, Fe, Mn, Cu, Cd, V, Co, Cr, Ni, As, Sb, Tl, Pb, Zn, Al, Hg and Mo were determined by extraction—a.a.s. and compared to results obtained by lithium tetraborate fusion—energy-dispersive x-ray fluorescence spectrometry and electrothermal a.a.s. after digestion of the fused borosilicate glass. Good accuracy for Mn, Cu, V, Cr, Ni, As, Pb, Zn, Hg and Mo was obtained for both SRM-1645 and fluvial sediments. The low values found for Fe, Cd, Co, Sb and the alkali and alkaline earth metals were shown to be caused by incomplete extraction. All minor and trace elements, except manganese and zinc were determined by electrothermal a.a.s. and a detailed description of the problems encountered and of the matrix modification techniques applied is presented. This study demonstrates that electrothermal a.a.s. can be effective despite the presence of numerous matrix interferences but that this acid extraction procedure, although accurate and precise for most minor and trace elements determined, is inadequate for the dissolution of major elements in river sediments.

An electron spin resonance spectrometric investigation of natural, extracted and thermally altered kerogenous materials

Core cuttings from three wells representing a 1000–7000-ft range of depths were examined by ESR spectroscopy. The spectral parameters of some of the series of samples follow trends, as suggested by the ESR kerogen method for paleotemperature estimation, while the spectral parameters of other series of samples do not. Samples extracted with mineral acids exhibit spectra parameters which follow the proposed trends somewhat better, but show large local variations which appear to be due to factors other than paleotemperature. Thermally treated samples show a general increase in free radical concentration, although there are several anomalies. While the ESR-kerogen method of paleotemperature estimation appears to have potential due to the large variations in some of the observed parameters, factors such as mineral acid extraction and sample lithology, among others, need further investigation to refine the technique.

The Extraction of Uranium(VI) from Mineral Acid Solutions by Di-4-octylphenylphosphoric Acid (DOPPA)

Abstract The extraction of uranium(VI) from sulfuric, hydrochloric, nitric, and perchloric acid was studied using dioctylphenylphosphoric acid (DOPPA) in heptane as extractant. At low aqueous acid concentration, an ion-exchange mechanism was generally observed and the extracted species was of the type UO2A4H2. Deviation from this behavior was observed at higher acid concentrations. From perchloric acid solutions, after an initial decrease, the extraction coefficient increased after 3 to 4 N acid. Some of the explanations offered in the literature for this behavior in the case of di-2-ethylhexylphosphoric acid (DEHPA) have been critically examined. Extraction of mineral acids, particularly HCI and HNO3, was also observed with DOPPA but to a lesser extent than with DEHPA.

Extraction Separation Studies of Gold by 2-Hexylpyridine

Abstract The high molecular weight pyridine amine, 2-hexylpyridine, has been studied as a component of solvent extraction systems. Extraction of mineral acids by the compound is described. The ionization constant (pKBH +) has been determined by potentiometric titration and spectrophotometrically. The distribution of Au(III) between solutions of 2-hexylpyridine in benzene and different mineral acid solutions has been investigated as a function of the concentration of the acids, extractant, and salting-out agents. The extraction mechanism and the composition of extracted complexes of Au(III) are discussed. Separation factors of a number of metal ions relative to gold have been reported, and the determination of gold from a number of synthetic and ore samples was made by neutron activation analysis. 2-Hexylpyridine has been shown as a selective extraction reagent for gold. It has been shown that 2-hexylpyridine dissolved in benzene will extract gold efficiently and reversibly from moderate acid chloride, nit...