Mono-compartment vs. Two-compartment with pregrinding

Good morning,

We know a plant which is operating a 4.2 x 13 m L mono-compartment ball mill with rollerpress pregrinding (ball mill inlet blaine 2,200).

Pi of the mill is 3,150 kW - calculated Pabs 2,988 kW which results in ~15 kWh/t specific power consumption at a production of 200 t/h and blaine of 3,600.The ball mill is running in closed circuit with a separator at nominal airflow of 300,000 m3/h. The grinding media filling rate is 27 % (220 t) and the media used is only 25-15 mm.

Does anyone know arguments why converting this mill into a 2-compartment mill could bring benefits, as the spec. power consumption is low and the output is high. Can you only argue with less overgrinding/better cement quality?

 Thanks a lot

Stefan