Method and system for operating a comminution process in a ball mill

A method of operating a comminution process in

• a ball mill including a rotatable shell having an internal shell surface with a first number of protrusions configured to engage a charge of material for grinding received solid material feed particles by tumbling the material in the rotating shell so as to generate product particles at a mill output, thereby causing a vibration having a first repetition frequency dependent on a speed of shell rotation when a protrusion engages with a toe portion of said material;
• the method comprising
• rotating the shell at a constant, or substantially constant, speed of shell rotation during operation of the ball mill;
• providing a solid material feed rate set point value for setting a solid material feed rate;
• said solid material feed rate being an amount per time unit, of said feed particles, that is being fed into an input of a ball mill thereby influencing an internal state of said comminution process;
• analysing at least a portion of said product particles;
• generating at least one product measurement value based on said product particle analysis;
• said at least one product measurement value being indicative of a product particle median size;
• receiving a vibration signal indicative of said vibration;
• receiving a position signal indicative of a rotational position of said rotating shell;
• generating, based on said vibration signal and said position signal, at least one status parameter value indicative of said internal state;
• said at least one status parameter value including a toe position value indicative of a position of the toe portion;
• receiving data indicative of a desired product particle median size and/or desired product particle size distribution;
• generating a toe position reference value based on said data indicative of said desired product particle median size and/or desired product particle size distribution, and a correlation data set;
• said correlation data set being indicative of a causal relationship between a certain toe position value and a corresponding certain product particle median size, at said speed of shell rotation;
• and/or indicative of a causal relationship between a certain internal state and a certain product particle size distribution;
• causing a user interface to convey information indicative of said toe position reference value and causing a user interface to convey information indicative of said toe position value, receiving, via a user interface, first user input relating to said solid material feed rate;
• generating said solid material feed rate set point value thereby influencing said internal state for controlling or affecting said product particle median size;
• wherein said generated solid material feed rate set point value is based on said received first user input.