摘要
This work presents the effect of mechanochemical activation in an attrition mill, in water medium and for different time intervals, on the particle size distribution and microstructure of copper concentrate as well as, on the oxidation of the metal sulphides after treatment in an autoclave. Results show that the mean particle size decreased after 30 minutes of milling almost 10 times and the specific surface increased from 0.1 to 4.3 m(2)/g. Regarding the micro-structural changes, it was found that during the mechanochemical activation the average crystallite size of chalcopyrite decreased, following an exponential trend towards a limiting value of approximately 20 nm, assuming spherical or equiaxed crystallites. The enhanced structural disorder of chalcopyrite is also highlighted by the linear increase of lattice strain with the milling time. Finally, results from the leaching experiments, demonstrated that the mechanical treatment improved the oxidation of sulphides by lowering the reaction temperature and increasing the reaction rates. The above data suggest that the mechanochemical activation of copper concentrate is an efficient method to enhance the hydrometallurgical oxidation of copper concentrate and chalcopyrite in particular.
- 出版日期2012-6