One of the factors which are usually difficult to be measured in mills is the grindability and distribution of feed under real situation and in a short time. In the condition of achieving a fast and convenient way to determine these parameters, the proper relationship between energy, hardness and particle size distribution can be obtained. Feed hardness is one of the most important factors in grinding of minerals in mineral-processing process, and this parameter depends on factors, such as the mechanical properties of minerals and collision conditions. The efficient use of energy during grinding of minerals in mills is one of the main objectives of this research. This research tried to provide an experimental method based on real collision conditions in a mill. Nowadays, SAG design test is used for evaluation of grinding circuit in the time of change in feed particle size distribution, size of the ball and the speed of mill, and for the prediction of energy required for complete grinding in AG and SAG mills. In this study, a new SAG design test for measuring the amount of specific energy and feed grindability was suggested and the effect of various parameters on product size distribution and hardness results was assessed. Results show the deviation of the A×b estimated by new method with values of drop weight tests were less than 1.9 percent. This new model can also be used to accurately predict the specific energy and particle size distribution.. Manuscript profile