Wpływ tlenu rozpuszczonego w ciekłej miedzi na proces eliminacji z niej bizmutu

• Autorzy: Fornalczyk A. , Blacha L.

Warianty tytułu

EN

Influence of oxygen dissolved in liquid copper to bismuth removal

• Języki publikacji: PL

Abstrakty

PL

W artykule podjęto badania mające na celu określenie wpływu tlenu zawartego w ciekłej miedzi na szybkość usuwania z niej bizmutu na drodze rafinacji próżniowej. Badania te podjęto, gdyż metalu tego nie można usunąć z miedzi na drodze jej elektrorafinacji do zawartości odpowiadającej normom miedzi beztlenowych. Założono też, że tlen może w znaczący sposób wpływać na ten proces. Tlen należy do substancji powierzchniowo aktywnych, które mają zdolność do gromadzenia się na powierzchni międzyfazowej ciekła faza metaliczna-faza gazowa. Tym samym może w sposób istotny wpływać na szybkość procesu, szczególnie w przypadku, gdy ten determinowany jest transportem masy. Wpływ ten objawia się poprzez obniżenie napięcia powierzchniowego, co powoduje utrudnienia w przedostaniu się elementu ciekłego metalu z głębi fazy na powierzchnię. Jednocześnie tlen może powodować powstawanie na powierzchni międzyfazowej blokującej warstwy tlenku metalu.

EN

In present work were executed the tests aimed at determination of the presence of oxygen contained in liquid copper upon a rate of bismuth removal by means of vacuum refining. These examinations were undertook because it was assumed, that oxygen may have a significant effect on this process. The oxygen, like a sulfur, selenium and tellurium belongs to surface-active substances, which have tendency to accumulation at interfacial surface: metallic liquid phase-gaseous phase. Because of that, they can influence significantly the rate of process, especially in case when mass transfer determines it. This influence is manifested by reduction of surface tension, what provokes difficulties in passing of liquid metal from deep inside the phase onto a surface. At the same time oxygen can cause creation of a locking layer of metal oxide at interfacial surface. Description of gaseous phase composition would require to have at disposal the data related with the type of particles being present therein, as well as the data concerning the constants of reaction equilibrium, their generation and description of thermodynamic properties of components in condensed phase of this system. In case of copper in gaseous phase the only components recorded in quantities essential to presented analysis are particles of Cu(g) monomer. These data with reference to bismuth are showing a presence Bi(g) and Bi2(g), in gaseous phase. In case of the presence of oxygen in the system, there are also present the particles of BiO(g), Bi20(g), Bi202(g), Bi203(g), Bi304(g), Bi406(g) [1]. Performed analysis of equilibrium composition of gaseous phase over liquid Cu-Bi-O solutions had proved, that a rise of oxygen content up to 1 % wt. in liquid alloy does not reduce considerably the partial pressure of bismuth. It also causes no distinct rise of the pressure of bismuth oxides with respect to bismuth partial pressure. It means, that from thermodynamic point of view the elimination of bismuth in vacuum refining process is not executed for such alloys by means of evaporation of volatile oxides of this metal. To perform evaluation of the influence of oxygen contained in liquid copper upon process of bismuth elimination, there were executed the tests of vacuum refining of Cu-Bi-0 alloys containing up to 1 % bismuth and 0.5 % oxygen. The tests were made at temperatures 1373 and 1523 K under 67 Pa, 13.3 Pa and 1.33 Pa pressures. For these tests was used a laboratory vacuum furnace VSG-02 Balzers. A sample of alloy was placed in crucible made of Al203. The first sample was cast into a graphite mould, while the second was left in crucible. The obtained sample was weighed and subjected to chemical analysis. The performed own research on elimination of bismuth from Cu-Bi-0 alloys had confirmed the initial thermodynamic analysis of process namely, had showed no influence of oxygen contained in liquid copper on the tested process. It can be stated, that the oxygen contained in copper is causing no inhibition in the process of bismuth elimination, nor by reduction of liquid metal surface tension nor by creation of a locking layer of bismuth oxides. Basing on performed research, as well as on calculations of equilibrium composition of gaseous phase over liquid solutions Cu-Bi-0 it can be stated, that increase of oxygen in liquid alloy does not cause in any distinct degree the bismuth partial pressure, nor is causing any distinct rise the partial pressure of bismuth oxides with regard to bismuth pressure. This means, that the process of bismuth elimination from liquid copper can be executed only by evaporation of metallic admixture and not by evaporation of volatile oxides of this metal.

Słowa kluczowe

PL

tlen; tlen rozpuszczony w ciekłej miedzi; eliminacja bizmutu; rafinacja próżniowa

EN

oxygen; oxygen dissolved in liquid copper; bismuth removal; vacuum refining

• Wydawca: Wydawnictwo SIGMA-NOT
• Czasopismo: Rudy i Metale Nieżelazne
• Rocznik: 2004
• Tom: R. 49, nr 8
• Strony: 388--392
• Opis fizyczny: Bibliogr. 9 poz., rys., tab.

Twórcy

autor

Fornalczyk A.

• Politechnika Śląska, Katedra Metalurgii, Katowice

autor

Blacha L.

• Politechnika Śląska, Katedra Metalurgii, Katowice

Bibliografia

• 1. HSC Chemistry Ver.4.1 Copyright (C), Outocumpu Research Pori, Finland, A. Roine
• 2. Fornalczyk A., Niesiony B., Łabaj J.: Acta Metallurgica Slovacj Kosice 2001, nr 5, s. 555.
• 3. Kulkami A. D.: Metali. Trans. B, 1973, t .4, s. 1713+1721.
• 4. OzberkE., Gulhrie R.: Metali. Trans. B, t. 17B, March 1986+19S s. 87+100.
• 5. Roine A., Jalkanen H.: Metali. Trans. B, t. 16B, March 198j s. 129+141.
• 6. Zajączkowski A.: Prężność par i właściwości termodynamiczne ukłs du Cu-Bi. Metale Nieżelazne '95, s. 23+32, Faculty of Non-Fcrrous Metal o Stanisław Staszic, University of Mining and Metallurgy and KGHM Polsk Miedź S.A. 2-nd Internacionale Conference, Kraków, Poland, Septemb* 7+9, 1995.
• 7. Wypartowicz /., Filtzner K.: Aktywność tlenu w rozcieńczonycj roztworach bizmutu miedzi. Archiwum Hutnictwa 1983, t. 28, z. s. 209+219.
• 8. Kojo 1. V., Taskinen P. A.: Erzmetall. 1987, t. 40, s. 138+144.
• 9. Jiang X. H, Lynch D. C, Darenport W. G.: Interaction of iron ant bismuth in molten copper. Trans. lnst. Min. Metali. C, 97, 1988, s. 102.