Comparative Study of the Breakage Mechanisms on Minerals Liberations and Particles Shape in the Flotation of Copper Sulfide Ore

A sulfide copper ore was crushed to 100% passing 3.36mm followed by grinding the crushed product through bed breakage process in a piston- die cell or ball mill into to 100% passing 250μm. Revealed by the results of particle size analysis made on the ground products, the bed breakage method provides a finer product compared to the ball mill approach. The liberation analysis of the products in eight size-fractions showed that the chalcopyrite in the ball mill product was more liberated compared to the bed breakage product. The overall percentage of chalcopyrite liberation in the ball mill product was higher than the bed breakage product by 1.82%. The shape properties of particles in the breakage products were examined by analysis of scanning electron (SEM) images. Accordingly, it was found that the circularity and roundness of particles broken by the bed breakage method are higher than the particles broken by the ball mill method, while the ball-milled particles are more elongated. The results of micro-flotation tests indicated the efficiency rate of Cu recovery and separation in the ball mill product were respectively 11% and 15% higher than the bed breakage product. This better metallurgical performance can be attributed to the fact that the bed breakage product was finer, the chalcopyrite was more liberated in the ball milling product, and particles in the ball milling product had less circularity and roundness. Contrary to many previous studies, the results of this study indicated that the bed breakage method did not increase the mineral liberation and improved the performance of the flotation process.