Zn-Fe-O phases formed during roasting of concentrates from zinc sulfide ores produce soluble zinc oxide, oxy-sulfates and insoluble ferrite compounds. The ferrites have a general formula ZnOFe2O3. However, these ferrites have a range of magnetic properties, suggesting variable stoichiometry. Scanning electron microscopy has been used to obtain the general relationship between the Zn/Fe ratio of the ferrites and their magnetic susceptibility.
Lastra, R.; Rowlands, N.; and Finch, J. A.
"Evidence of Variable Zn/Fe in Zinc-Ferrites Produced From Roasting of Zinc Sulphide Concentrate,"
Scanning Microscopy: Vol. 2
, Article 19.
Available at: https://digitalcommons.usu.edu/microscopy/vol2/iss3/19