The Reduction of Copper Ferrite CuFe<SUB>2</SUB>O<SUB>4</SUB> with Carbon Monoxide

DOI Web Site Web Site

Bibliographic Information

Other Title
  • 一酸化炭素による亜鉄酸銅の分解
  • イッサンカ タンソ ニ ヨル アテツサン ドウ ノ ブンカイ
  • 複雑硫化鉱の製錬に関する研究 (第3報)
  • Studies on the extractive metallurgy of complex sulfide ores (3rd Report)

Search this article

Abstract

The effects of roasting temperature, carbon monoxide concentration and PCO2/PCO ratio of CO-0O2-N2 atmosphere on the reduction rate of copper ferrite were investigated.<BR>Copper ferrite was made from the stoichiometric mixture of cupric oxalate and ferrous oxalate by consecutive thermal treatments for 5 hrs at 1, 000°C and for 5 hrs at 800°C.<BR>Reduction products at the first stage were porous metallic copper and magnetite, and at the second stage the magnetite was further reduced to wustite according to the conditions in which PCO2/PCO ratio was 1. 3 and roasting temperatures were 700°C and 800°C.<BR>3CuFe2O4+4CO3=3Cu+2Fe3O+F4CO2 (1)<BR>Fe3O4-1-CO=3FeO+CO2 (2)<BR>Rhombohedral copper ferrite CuFeO2 as an intermediate phase of the reduction products was not detected in the reaction (1).<BR>A reacted quantity of copper ferrite in the roasting was linearly proportional to a reaction time, that is to say, the reaction rate is constant, r=dx/dt=k, xm=kt<BR>K is proportional to pco4/5 within a range of this study and the energy of activation of the reaction (1) is 1.9 kcal/mol, therefore it is considered that the velocity controlling step of the reaction (1) is a diffusional process.<BR>The magnetite as a reduction product of copper ferrite was very easily soluble in 0.1N H2SO4solution. The leach solution of the reduction products contains Cu2+ ion, Fe2+ ion and very little amount of Fe3+ ion. This can be explained by the fact that the metallic copper is corroded with Fe3+ ion, while Fe3+ ion is reduced to a Fe2+-state at the same time. Accordingly, the larger the amount of dissolved magnetite is, the more copper is leached into the solution. Even though a much amount of oxide of iron is dissolved, the quantity of leached copper is small when the oxide of iron exists as wustite only.<BR>From the above-mentioned facts, it is concluded that iron oxide as a reduction product of copper ferrite must be needed to exist as wustite because it is required to let metallic copper remain as it is, considering the separation of zinc oxide from metallic copper by only dilute sulfuric acid leaching after a selective reduction roasting of dead roasted complex sulfide ores.

Journal

Details 詳細情報について

Report a problem

Back to top