(1) Feed Particle Size Composition.   

Semi autogenous mill uses steel ball as grinding medium. Adding steel ball can stabilize the proportion of grinding medium, so as to stabilize the output of semi autogenous mill. The grinding medium of the autogenous mill mainly comes from the lump ore in the feeding, and the particle size is usually 100 ~ 350 mm. The new ore must contain enough lump ore and enough fine ore to maximize the output of the autogenous mill, which brings great challenges to the upstream coarse breaking, mining blasting operation and production allocation management.

(2) Crushing Efficiency of Hard Rock.  

The grinding process of autogenous mill is an iterative process of "crushing large blocks into small blocks and crushing small blocks into powder", but its efficiency in treating hard stones is low, so it is necessary to complete the hard stone crushing operation with the help of crusher. The efficiency of the self grinding circuit determines the output and effect of the self grinding operation to a great extent.

(3) Product Classification Efficiency of Self Grinding Circuit.  

For the fully closed-circuit self grinding process, the classification method and classification efficiency will greatly affect the output of the autogenous mill.

(4) New Ore Properties.

There are many different ore bodies in general large deposits, and the ore properties between ore bodies are also obvious, especially the ore hardness and grindability. The change of ore properties is bound to affect the stable output of autogenous mill.