Thermal Analyses of Silver-Based Sulfosalts in Air

A3 Bokavsnitt, kapitel i forskningsböcker


Interna författare/redaktörer


Publikationens författare: Fiseha Tesfaye, Daniel Lindberg
Redaktörer: Antoine Allanore, Guillaume Lambotte, Jonghyun Lee
Publiceringsår: 2017
Förläggare: Springer
Moderpublikationens namn: Materials Processing Fundamentals 2017
Seriens namn: The Minerals, Metals & Materials Series
Artikelns första sida, sidnummer: 55
Artikelns sista sida, sidnummer: 64
ISBN: 978-3-319-51579-3
eISBN: 978-3-319-51580-9
ISSN: 2367-1181


Abstrakt

The sulfosalts Ag 0.93Cu 1.07S (stromeyerite) and α-AgBiS 2 (schapbachite) have been studied under oxidizing conditions at elevated temperatures. The sulfosalts were synthesized from the pure simple sulfides in evacuated quartz ampoules. The synthesized samples were thermally analyzed in the temperature range from 298 to 1173 K by a simultaneous DTA-TGA analyzer . Based on the DTA measurements the phase transition of stromeyerite to the solid solution (Cu, Ag) 2S(hcp) in air is determined to be T = (360.9 ± 2) K. For the first time, maximum thermal stability of (Ag, Cu) 2S in an oxidizing atmosphere close to the partial pressure of oxygen in air ( P(O 2) ≈ 0.20 atm) is determined to be below T = (614 ± 2) K, above which it oxidizes to form Ag, CuO and Ag 2SO 4. The melting temperature of Ag 2SO 4 determined from the cooling DTA curve, T = (932.76 ± 2) K, is in good agreement with the literature value. Below T = 1173 K, the oxidation process for schapbachite in air has been indirectly determined to be: 2AgBiS 2 + 5.5O 2(g) ⇄ 2Ag + Bi 2O 3 + 4SO 2(g).


Nyckelord

Optimization, Oxidation/Reduction, Silver, sulfosalts, sulphides, Sustainability

Senast uppdaterad 2019-14-10 vid 05:56