The chlorination of zinc oxide between 723 and 973 K. A kinetic model.

GEORGINA DE MICCO; GASTÓN GALO GOUGA; ANA ESTER BOHÉ

METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE

David E. Laughlin-TMS

Año: 2007 vol. 38B p. 853 - 862

1073-5623

The kinetics of the chlorination of zinc oxide has been studied by thermogravimetry between  723 and 973 K. The starting temperature for the reaction of ZnO with chlorine is determined at  about 498 K. The influence of gaseous flow rate, sample mass, temperature, and chlorine partial  pressure in the reaction rate is analyzed. It is established that the reaction occurs under mixed  control, being pore di_usion coupled with chemical reaction as the rate controlling step. An  apparent reaction order of 0.5 with respect to chlorine partial pressure was determined. A  kinetic model for the chlorination reaction of porous solids under mixed control determined an  intrinsic reaction order of zero with respect to partial pressure of chlorine and an intrinsic  activation energy of 249 kJ mol-1.