Abstract: To establish an evaluation method for the grindability of tower mills and enable effective prediction of their specific energy consumption,this study took an Anshan-type magnetite ore as the research object and,based on a modified Hardgrove grindability test,proposed a test method for characterizing the grinding performance of tower mills.Samples of two size fractions,-3 mm and -1 mm,were each divided into four narrow size fractions and ground using a Hardgrove grindability tester,with different rotation numbers representing different input energy levels.Mathematical models relating the grinding product t4 to specific energy consumption for each narrow size fraction were constructed based on the A×b breakage model and the fmat breakage model,respectively,and the model parameters under the two feed sizes were fitted.The prediction results were then verified through laboratory tower mill grinding tests.The results show that when fitted with the A×b model,the A×b values for the -3 mm and -1 mm feeds are 16.72 and 11.53,respectively;When fitted with the fmat model,the corresponding ore hardness indices SMi are 4.78 and 3.88,indicating that the finer the feed size,the lower the shear grindability.The SMi values obtained from the fmat model were used to predict the theoretical specific energy consumption of the tower mill,and the coeffi cient of determination R2 between the predicted and actual maximum specific energy consumption reached 0.98.This method can effectively evaluate the grindability of materials in tower mills and provide a reliable basis for predicting the useful specific energy consumption of tower mills.

Key words: tower mill,grindability,breakage model,specific energy consumption,magnetite