Leaching of chalcopyrite with ferric ion. Part I: General aspects

Copper isotope fractionation in acid mine drainage

Chalcopyrite (CuFeS2) is a widespread natural mineral, composed of earth-abundant and nontoxic elements It has been considered a promising n-type material for thermoelectric applications In this work, a series of Zn-doped Cu1–xZnxFeS2 (x = 0–01) compounds are synthesized by vacuum melting combined with the plasma activated sintering process The role of Zn in the chalcopyrite and its different effects on thermoelectric properties, depending on its concentration and location in the crystal lattice, are discussed It is found that Zn is an effective donor which increases the carrier concentration and improves the thermoelectric properties of CuFeS2 When the content of Zn exceeds the solubility limit, Zn partially enters the Cu sites and forms in situ ZnS nanophase This, in turn, shifts the balance between the anion and cation species which is re-established by the formation of antisite Fe/Cu defects Beyond maintaining charge neutrality of the structure, such antisite defects relieve the lattice strain in the matrix and increase the solubility of Zn further The highest ZT value of 026 is achieved at 630 K for Cu092Zn008FeS2, which represents an enhancement of about 80% over that of the pristine CuFeS2 sample

G. A. Sawatzky

Papers

Cu and Fe valence states in CuFeS2

Covalency effects in divalent iron compounds