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Oznaczanie zanieczyszczeń śladowych w kwasie ortofosforowym(V) jakości EG metodą ICP-MS

Milde Anna, Stypka Mariusz

Przemysł Chemiczny

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2024

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T. 103, nr 4

545--548

PL

Opracowano metodę oznaczania zanieczyszczeń śladowych w stężonym kwasie ortofosforowym(V) jakości elektronicznej za pomocą spektrometru ICP-MS oraz przeprowadzono jej walidację. Dla wszystkich oznaczanych pierwiastków uzyskano bardzo dobrą liniowość (r > 0,999) oraz granice oznaczalności na poziomie 10 ppb. Wykazano, że założone parametry zostały spełnione, a metodę uznano za przydatną do stosowania w rutynowej kontroli produktu w Laboratorium Kontroli Jakości.

EN

A multi-element method for analyzing trace amts. of elements in concd. EP-grade H₃PO₄ by ICP-MS spectrometry was developed. Validation criteria were defined and the method was validated. Very good linearity (r > 0.999) and limits of quantification at 10 ppb were obtained for all elements detd. The method can be used for qual. control of concd. H₃PO₄.

2

Effect of Na3VO4 Inhibitor on the Corrosion Resistance of Al2Cu Intermetallic Phase in H3PO4 Aqueous Solution

Kwolek P.

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 1

175--183

EN

Sodium orthovanadate was tested as a corrosion inhibitor of intermetallic Al2Cu in 1 M H3PO4. The Al2Cu–H3PO4–Na3VO4system was studied using the following methods: inductively coupled plasma optical emission spectrometry, scanning electron microscopy with energy dispersive x-ray spectroscopy, x-ray diffraction, electrochemical impedance spectroscopy, polarisation and open circuit potential. It was found that the corrosion rate decreased as the inhibitor concentration increased. The highest inhibition efficiency 99% was obtained when sodium orthovanadate initial concentration was equal to 100 mM, pH = 1.11, due to precipitation of a protective layer of insoluble salt, containing vanadium, phosphorus, sodium and oxygen, on the surface. At pH = 0.76 the protective layer was not formed and inhibition efficiency decreased to 76%. Selective corrosion of the intermetallic phase caused a significant increase of an electric double layer capacitance and decrease of a charge transfer resistance.

3

Selective Corrosion of Al2Cu Intermetallic Phase in Orthophosphoric Acid Aqueous Solutions

Kwolek P., Gradzik A., Szeliga D., Kościelniak B.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 4

1223--1229

EN

Al2Cu phase has been obtained by melting pure metals in the electric arc furnace. It has been found that the intermetallic phase undergoes selective corrosion in the H3PO4 aqueous solutions. Aluminium is dissolved, the surface becomes porous and enriched with copper. The corrosion rate equals to 371 ±17 g∙m-2∙day-1 (aerated solution) and 284 ± 9 g∙m-2∙day-1 (deaerated solution). The surface of Al2Cu phase after selective corrosion was characterised by using electrochemical impedance spectroscopy. It was found that the surface area of the specimens increases with temperature due to higher corrosion rate and is between 2137 and 3896 cm2.

4

Sodium molybdate as the corrosion inhibitor of aluminium alloys in the acidic solution

Kwolek P., Sieniawski J.

Ochrona przed Korozją

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2018

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nr 4

86--89

EN

The influence of the initial concentration of sodium molybdate on the mechanism of corrosion of the unalloyed aluminium (1050) and Al2Cu phase in 0.5 M H3PO4 was studied. Sodium molybdate is a promising alternative for chromate-containing corrosion inhibitor of aluminium alloys in the acidic media. In the studied solutions, molybdic blue species are formed. They are efficient inhibitors of corrosion of unalloyed aluminium in the acidic solution. Inhibition efficiency equals to 97%. Al2Cu phase in the acidic solution undergoes selective corrosion. Aluminium is leached, the porous copper structure remains on the surface. Sodium molybdate prevents from this process only temporarily.

PL

Określono wpływ stężenia początkowego molibdenianu sodu na mechanizm procesu korozji aluminium o czystości technicznej (EN-AW 1050) i fazy międzymetalicznej Al2Cu w wodnym roztworze H3PO4 o stężeniu 0,5 mol∙dm−3 . Molibdenian sodu jest potencjalnym zamiennikiem dla chromianów, - inhibitorów korozji stopów aluminium w środowisku kwaśnym. Stwierdzono, że w badanych roztworach wytwarzane są aniony błękitu molibdenowego – jest skutecznym inhibitorem korozji aluminium. Określono stopień ochrony przed korozją - 97%. Faza Al2Cu ulega korozji selektywnej w roztworze kwaśnym. Atomy glinu przechodzą do roztworu – warstwa wierzchnia elektrody zostaje wzbogacona w miedź i jest porowatą. Ustalono, że molibdenian sodu chroni fazę Al2Cu przed procesem korozji selektywnej tylko przez krótki czas.

5

Acids in bitumen emulsions

Solodkyy S., Sidun I., Vollis O.

Czasopismo Inżynierii Lądowej, Środowiska i Architektury / Journal of Civil Engineering, Environment and Architecture

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2018

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z. 65, nr 3

83--90

EN

In the article there is proved the possibility of using ortho-phosphoric acid with special emulsifiers instead of hydrochloric acid - for the production of road cationic slow-setting bitumen emulsions. There is ascertained the difference between used for bitumen emulsions distilled binder (Nybit E85 bitumen), produced from heavy crude oil, and oxidized bitumens (grade 70/100 bitumen produced by JSC Mozyr Refinery and grade BND 60/90 bitumen of JSC UkrTatNafta), produced from light crude oil. The difference is analyzed between physical-mechanical indices of distilled and oxidized bitumens. Eight bitumen emulsion formulations were developed based on usage hydrochloric acid, three bitumens and three emulsifiers (Redicote E-11, Redicote 404 and Redicote E-4875), as well as four formulations based on usage of ortho-phosphoric acid, two bitumens and two emulsifiers (Redicote EM44 and Redicote C-320). There was investigated the influence of hydrochloric and ortho-phosphoric acids upon the physical-technical indices of road cationic slow-setting bitumen emulsions and the difference was ascertained between the indices of bitumen emulsions based on distilled and oxidized bitumens. Bitumen emulsion formulations were developed based on usage of ortho-phosphoric acid and special emulsifiers for the class of cationic slow-setting emulsions for slurry seal and microsurfacing mixtures.

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Carbon-13 isotope effect for decarboxylation of phenylpropiolic acid (PPA) in orthophosphoric acid

Zielińska A., Zieliński M., Zielińska-Papiernik H.

Nukleonika

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1999

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Vol. 44, nr 3

403-410

EN

The carbon-13 isotope effect accompanying decarboxylation of phenylpropiolic acid in 85% orthophosphoric acid has been studied in the temperature range 323-353 K. The first fraction of CO2 was found to be generated at 323 K in 85% H3PO4 with the carbon-13 isotope effect, k[indeks dolny]12/k[indeks dolny]13, equal to 1.011-1.015. The subsequent fractions of carbon dioxide produced in the temperature range 323-353 K have shown none but about 0.2% per cent kinetic isotope effect (KIE). It has been suggested that the initial larger carbon-13 fractionation, accompanying the decarboxylation of PPA in 85% orthophosphoric acid, is caused by isotopic equilibra linking decarboxylating monomeric species of PPA with dimeric and larger units formed during solvation and dissolving of solid PPA in orthophosphoric acid. The solvated PPA molecules are decarboxylated in the homogeneous solution with a negligible carbon-13 KIE. The triple bond of phenylpropiolic acid is attacked by the hydrated protons, H3O⊕aq, and formation of the Calpha-H bond is the rate determining step. The bond rupture between the alpha carbon and the carboxyl group is the next fast reaction step. The enthalpy of activation, ΔH[indeks górny]≠ = 123.4 kJ/mol, and the positive entropy of activation, ΔS≠ = +30 e.u.(SI), exclude the chelate like structure of the transition state. This suggests a flexible structure of the transition state complex which must be less solvated than in the initial state. Some further studies of the carbon-13 KIEs in phosphoric acid environment are suggested.

PL

Zbadano efekt izotopowy 13C w reakcji dekarboksylacji kwasu fenylopropiolowego (PPA) w 85% H3PO4 w 323-373 K. Delta (PDB) pierwszej porcji dwutlenku węgla, przy stopniach dekarboksylacji około f= 0.1, wskazuje na jej początkowe wzbogacenie w 13C o około 1,0-1,5%. Spowodowane jest to prawdopodobnie procesami równowagowymi, zachodzącymi między ulegającymi dekarboksylacji monomerami PPA a większymi agregatami, powstającymi w wyniku oddziaływania kryształów PPA z uwodnionymi cząsteczkami kwasu ortofosforowego. Dalsza dekarboksylacja PPA przebiega w roztworze homogenicznym bez wyraźnego rozfrakcjonowania izotopów węgla. Przyłączenie protonów do wiązania potrójnego i tworzenie wiązania Calfa-H zachodzi w etapie krytycznym reakcji, poprzedzającym właściwą dekarboksylację, tj. utratę cząsteczki dwutlenku węgla przez kwas fenylopropiolowy. Entalpia aktywacji ΔH[indeks górny]≠ = 123,4 kJ/mol i dodatnia entropia aktywacji ΔS[indeks górny]≠ = +30 e.u.(SI) sugerują niecykliczny, swobodny, stan przejściowy kompleksów reakcji dekarboksylacji PPA w 85% kwasie ortofosforowym. Zaproponowano dalsze badania efektu izotopowego 13C w środowisku kwasów fosforowych.