Diffusion of oxygen in liquid copper and nickel

Authors
Citation
Mg. Hocking, Diffusion of oxygen in liquid copper and nickel, T I MIN M-C, 109, 2000, pp. C79-C82
Citations number
19
Categorie Soggetti
Geological Petroleum & Minig Engineering
Journal title
TRANSACTIONS OF THE INSTITUTION OF MINING AND METALLURGY SECTION C-MINERALPROCESSING AND EXTRACTIVE METALLURGY
ISSN journal
03719553 → ACNP
Volume
109
Year of publication
2000
Pages
C79 - C82
Database
ISI
SICI code
0371-9553(200005/08)109:<C79:DOOILC>2.0.ZU;2-9
Abstract
The diffusivities of oxygen in liquid copper and nickel were determined fro m 1300 degreesC to 1560 degreesC by a capillary gas-reservoir method. A dif fusion cell designed to behave as if of semi-infinite length and consisting of liquid copper or nickel held in an alumina capillary was used. A H2O-H- 2 gas mixture maintained a constant oxygen potential at the metal-gas inter face. A controlled furnace hot zone of 15 cm was obtained with six separate windings of Pt-10%Rh wire. To prevent convection the top of the diffusion cell was adjusted to be hotter than the bottom. The solidified diffusion co lumns were sectioned and analysed for oxygen by vacuum fusion analysis. Oxy gen diffusivities, D, were calculated through use of a solution of Fick's s econd law. For copper D is 1.52 x 10(-8) m(2)/s at 1295 degreesC and 3.78 x 10(-8) m(2)/s at 1560 degreesC; for nickel D is 3.12 x 10(-8) m(2)/s at 14 50 degreesC and 3.39 x 10(-8) m(2)/s at 1580 degreesC. The results for copp er can be represented by the Arrhenius relationship In D equals -19570/RT 3.21 where E and R are in calories or -81900/RT + 3.21 where E and R are i n joules (1350-1560 degreesC) and where the numerator, E, is oxygen diffusi on activation energy/mol K and R is the gas constant.