Determination of zinc compounds in the recovered dusts from the electric furnace dusts

The analytical methods for Zn compounds in the dust recovered from the electric furnace dust have been investigated. The recovered dust contains metallic Zn, ZnO, ZnS and trace amount of Zn(OH)(2) as Zn compounds. The sample was dissolved in the FeCl3-citric acid solution at room temperature. During the dissolution, metallic Zn reduced Fe(III) to Fe(II) quantitatively. The amount of Fe(II) was determined by the titration with potassium dichromate, and converted to the amount of metallic Zn. The ZnS contained in the residue was dissolved in HNO3 (1+1), and the amount of Zn as ZnS was determined by ICP-AES. The amount of ZnO and Zn(OH)(2) was obtained by subtracting the amounts of metallic Zn and ZnS from the amount of total Zn. The electric furnace dust contained ZnO and ZnFe2O4, and the FeCl3,-citric acid solution was used for the separation of ZnO from ZnFe2O4. Only ZnO was dissolved in the FeCl3-citric acid solution, and ZnFe2O4 contained in the residue was determined by ICP-AES after alkali fusion and acid dissolution.