The effect of mechanical activation on the thermal decomposition of chalcopyrite

Experimental results on the influence of preliminary mechanical activation on the thermal decomposition of chalcopyrite are presented and discussed. The following experimental facts were found:

1.	a decrease in the temperature of the endothermic DTA peak of-CuFeS2 from 821 K for a non-activated sample to 763 K for an optimally activated one;
2.	a decrease in the apparent activation energy of the thermal decomposition of CuFeS2 from 238 kJ mol–1 for a non-activated sample to 72 kJ mol–1 for an optimally activated sample.

The intensive grinding of chalcopyrite leads to a shift in temperature of the endothermic DTA peak and brings about a decrease in the activation energy of the thermal decomposition of CuFeS₂. These results can be attributed to the mechanically produced alterations in structure and surface properties of the mineral.