TY - JOUR
T1 - Applications of in situ synchrotron XRD in hydrometallurgy
T2 - Literature review and investigation of chalcopyrite dissolution
AU - Majuste, D.
AU - Ciminelli, V. S.T.
AU - Eng, P. J.
AU - Osseo-Asare, K.
N1 - Funding Information:
The authors are grateful to the Brazilian government agencies — CNPq , CAPES and FAPEMIG — and to the INCT-Acqua for financial support, and to the ANL (Argonne National Laboratory), USA , for the infrastructure to carry out the experiments. The first author thanks Andrew J. Wall and Claire R. Fleeger (Pennsylvania State University) for all the support on the construction work of the flow-through reaction cell. The authors would also like to thank the reviewers for their relevant contributions to the final version of the manuscript.
PY - 2013
Y1 - 2013
N2 - In situ synchrotron X-ray diffraction (S-XRD) techniques are potentially versatile research tools for advancing the current understanding on dissolution reactions of commercially important minerals. The paper presents a review on the applications of S-XRD to investigate solid phase transformations in aqueous media, with emphasis on reactions relevant to hydrometallurgy, including the dissolution of nickel laterite ores and metal sulfides, such as pyrite (FeS 2), bornite (Cu5FeS4) and chalcocite (Cu 2S). The results of an in situ synchrotron time-resolved X-ray diffraction (S-TRXRD) study of the dissolution of chalcopyrite (CuFeS 2) are also reported. The S-TRXRD measurements were carried out in capillary-based cells containing fine particles by using two different experimental approaches - flow method (FM) and non-flow method (NFM). At 25 °C (FM), no transformation of the crystal structure was observed, in agreement with the well-known slow dissolution rate of the mineral. In the temperature range 100-200 °C (NFM), the formation of covellite (CuS), elemental sulfur (S8), and metal sulfates (ferrous or cupric sulfates) was detected on CuFeS2 particles. Our results demonstrate that the mineral conversion to such product phases commenced about 10 min after the start of measurements, and suggested that the formation of elemental sulfur is possibly related to an initial oxidation of CuFeS2 by Fe 3+ ions, followed by CuS oxidation by the same oxidants. The new results in combination with the previous reports demonstrate that the S-XRD techniques can be used to improve our knowledge on key hydrometallurgical processes. This work highlights the features of different experimental set-ups and the possibilities to be explored by applying in situ methods, alone or in combination with other analytical tools.
AB - In situ synchrotron X-ray diffraction (S-XRD) techniques are potentially versatile research tools for advancing the current understanding on dissolution reactions of commercially important minerals. The paper presents a review on the applications of S-XRD to investigate solid phase transformations in aqueous media, with emphasis on reactions relevant to hydrometallurgy, including the dissolution of nickel laterite ores and metal sulfides, such as pyrite (FeS 2), bornite (Cu5FeS4) and chalcocite (Cu 2S). The results of an in situ synchrotron time-resolved X-ray diffraction (S-TRXRD) study of the dissolution of chalcopyrite (CuFeS 2) are also reported. The S-TRXRD measurements were carried out in capillary-based cells containing fine particles by using two different experimental approaches - flow method (FM) and non-flow method (NFM). At 25 °C (FM), no transformation of the crystal structure was observed, in agreement with the well-known slow dissolution rate of the mineral. In the temperature range 100-200 °C (NFM), the formation of covellite (CuS), elemental sulfur (S8), and metal sulfates (ferrous or cupric sulfates) was detected on CuFeS2 particles. Our results demonstrate that the mineral conversion to such product phases commenced about 10 min after the start of measurements, and suggested that the formation of elemental sulfur is possibly related to an initial oxidation of CuFeS2 by Fe 3+ ions, followed by CuS oxidation by the same oxidants. The new results in combination with the previous reports demonstrate that the S-XRD techniques can be used to improve our knowledge on key hydrometallurgical processes. This work highlights the features of different experimental set-ups and the possibilities to be explored by applying in situ methods, alone or in combination with other analytical tools.
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U2 - 10.1016/j.hydromet.2012.10.001
DO - 10.1016/j.hydromet.2012.10.001
M3 - Article
AN - SCOPUS:84868313332
SN - 0304-386X
VL - 131-132
SP - 54
EP - 66
JO - Hydrometallurgy
JF - Hydrometallurgy
ER -