Abstract
The transportation of W in aqueous gas-phases at and above 500°C is examined using thermodynamic data. The transport of W is possible as fluoride and oxifluoride. The deposition of wolframite continues with decreasing temperature and pressure. The stabilities of wolframates in hydrothermal solutions are examined for temperatures up to 300°C with Eh-pH-diagrams, exchange reactions of wolframite with oxides, sulfides and dissolved ions. Fe 2WO 6 becomes stable against Fe 2O 3 + WO 3 above 126°C. At 300°C its range of stability begins at high pO 2 which is not realised in hydrothennal endogenous solutions. In consequence of the very low Gibbs energies of MgWO 4, CaWO 4 and BaWO 4, the minerals MgWO 4 and BaWO 4 should be more important than wolframite, if Mg and Ba coexist in solution together with W. Co and Ni also should be found as trace elements in wolframite, if Co and Ni were in solution in sufficiently high concentrations together with W.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.