### Appendix A Report On Alkaline Carbonate Leaching At

Ball mills the ball charge in each mill is approximately 22 tons equa1 weights of 2 and 2 12 inch forged steel balls are used for charge make up each ball mill is driven by a 400 hp 4160 volt motor geared through a pinon shaft to the ball mill operation of the ball mills is maintained at 20 rpm or 83 of critical speed the ball discharge