Sulfur recovery from pyrite in annular fluidized bed

Abstract

To recover both elemental sulfur from pyrite and the heat generated from the roasting of pyrite and pyrrhotite, annular type fluidized bed was employed as a reactor, in which two main reactions occurred simultaneously. One was the oxidation of ferrous sulfide and the other was reaction of ferrous sulfide with sulfur dioxide produced from the previous reaction. Annular section was made of 4-inch and 2-inch stainless steel pipe. Used reactants were pyrite (domestic production) and air. The effects of particle size, reaction temperature, reaction time and superficial gas velocity on the reaction conversion were observed. In order to explain the reaction mechanisms and fluidized bed characteristics, shrinking core model and Kunii-Yagi``s model were applied in the present system respectively.