| A study has been made on the segregation reaction of nickel oxide with calcium chloride and carbon reductant over the temperature range from 700 to 1000℃ using a tube type furnace in an inert atmosphaere. The overall segregation reaction was found to consist of three steps: in the first step, clacium chloride is hydrolyzed generating hydrogen chloride gas, in the second step, nickel oxide is reacted with the hydrogen chloride gas and converted to nickel chloride, and in the third step, the nickel chloride is reduced by hydrogen as that is generated by the reaction of carbon reductant and water vapor. In the above reactions, the first and the third step were rapid in comparison with the second step. Consequently it is assumed that the second step reaction would be a rate determining step in the segregation reaction. The activation energy of the chlorometallization reaction of nickel oxide was determined for powder sample to be 10.5 ㎉/mold. The reaction rate was observed being approximately proportional to he partial pressure of hydrogen chloride gas and reaction temperature at constant water vapor pressure. |
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