TY - JOUR
T1 - Reaction mechanism and kinetics of enargite oxidation at roasting temperatures
AU - Padilla, Rafael
AU - Aracena, Alvaro
AU - Ruiz, Maria C.
N1 - Funding Information:
This work was supported by the National Fund for Scientific and Technological Development (FONDECYT) of Chile under Project No. 1080296.
PY - 2012/10
Y1 - 2012/10
N2 - Roasting of enargite (Cu3AsS4) in the temperature range of 648 K to 898 K (375 °C to 625 °C) in atmospheres containing variable amounts of oxygen has been studied by thermogravimetric methods. From the experimental results of weight loss/gain data and X-ray diffraction (XRD) analysis of partially reacted samples, the reaction mechanism of the enargite oxidation was determined, which occurred in three sequential stages: First stage: 4Cu3AsS4(s) + 13O2(g) = As4O 6(g) + 6Cu2S(s) + 10SO29g) Second stage: 6Cu2S(s) + 9O2(g) = 6Cu2O(s) + 6SO 2(g) Third stage: 6Cu2O(s) + 3O2(g) = 12CuO(s) The three reactions occurred sequentially, each with constant rate, and they were affected significantly by temperature and partial pressure of oxygen. The kinetics of the first stage were analyzed by using the model X = k1t. The first stage reaction was on the order of 0.9 with respect to oxygen partial pressure and the activation energy was 44 kJ/mol for the temperature range of 648 K to 898 K (375 °C to 625 °C).
AB - Roasting of enargite (Cu3AsS4) in the temperature range of 648 K to 898 K (375 °C to 625 °C) in atmospheres containing variable amounts of oxygen has been studied by thermogravimetric methods. From the experimental results of weight loss/gain data and X-ray diffraction (XRD) analysis of partially reacted samples, the reaction mechanism of the enargite oxidation was determined, which occurred in three sequential stages: First stage: 4Cu3AsS4(s) + 13O2(g) = As4O 6(g) + 6Cu2S(s) + 10SO29g) Second stage: 6Cu2S(s) + 9O2(g) = 6Cu2O(s) + 6SO 2(g) Third stage: 6Cu2O(s) + 3O2(g) = 12CuO(s) The three reactions occurred sequentially, each with constant rate, and they were affected significantly by temperature and partial pressure of oxygen. The kinetics of the first stage were analyzed by using the model X = k1t. The first stage reaction was on the order of 0.9 with respect to oxygen partial pressure and the activation energy was 44 kJ/mol for the temperature range of 648 K to 898 K (375 °C to 625 °C).
UR - http://www.scopus.com/inward/record.url?scp=84869879049&partnerID=8YFLogxK
U2 - 10.1007/s11663-012-9675-x
DO - 10.1007/s11663-012-9675-x
M3 - Article
AN - SCOPUS:84869879049
SN - 1073-5615
VL - 43
SP - 1119
EP - 1126
JO - Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science
JF - Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science
IS - 5
ER -