Probably this is the main factor to consider in any metallurgical evaluation. For example, native gold can be recovered by gravity equipment and the gravity tails needs to be reground to a finer size so that the net process can achieve a good performance. If gravity tails are processed by froth flotation, the flotation feed size must be ranging 70-75 passing 75 µm. If we considered cyanidation, the fineness of regrind is 85-90% passing 75 µm. Obviously, gold recovery processes have restrictions related to the gold particle size and no one can say that very fine particles are appropriate to achieve the best metallurgical performance. In this way, tiny particles such as 5 µm can create some problems during the cyanidation process. For this reason is important to evaluate the effect of the final grinding product on gold recovery in order to select the most appropriate size to use in the design. Also, the operative cost is directly influenced by the power consumption. Then, try to optimize this process is very important.
Cyanidation tests at different particle sizes