Closed circuit mineral for sale. Metallurgical ContentOpen Circuit GrindingClosed Circuit GrindingGrinding Circuit Process Control VariablesGrinding Operating Costs The simplest grinding circuit consists of a ball or rod mill in closed circuit with a classifier the flow sheet is shown in Fig 25 and the actual layout in Fig 9.As Grinding Becomes Finer Ball Mills Are Required And Closed Circuit Operation. Highefficiency Cement Grinding. Sep 17, 2012 Figure 1 Presents A Typical Process Flowsheet Of A Finish-Grinding System. The Grinding Plant Can Also Be Equipped With A Ball Mill Following The POLYCOM. This Is Called A Combi-Grinding Circuit.