Method and system for generating information relating to an internal state of a tumbling mill

A method for generating information relating to a grinding process in a tumbling mill having a shell that rotates around an axis at a speed of rotation for grinding a charge of material by tumbling the material in the rotating shell;

• said shell having an internal shell surface including a first number of protrusions configured to engage material as the shell rotates about the axis, said first number of protrusions being higher than one;
• the method comprising the following steps:
• receiving, from a position sensor, a position signal indicative of a rotational reference position of said rotating shell;
• generating, based on said position signal, a time sequence of position signal sample values including reference position signal values indicative of a certain number of reference positions per revolution of said rotating shell;
• said certain number being equal to said first number of protrusions;
• receiving a vibration signal dependent on mechanical vibrations emanating from rotation of said shell, said vibration signal including a time sequence of vibration sample values;
• detecting a first occurrence of a first reference position signal value in said time sequence of position signal sample values;
• detecting a second occurrence of a second reference position signal value in said time sequence of position signal sample values;
• detecting a third occurrence of an event signature in said time sequence of vibration sample values;
• said event signature being indicative of an impact force generated when a protrusion on the internal shell surface of the rotating shell interacts with a toe portion of the charge of material;
• generating data indicative of a temporal relation between
• a first temporal duration and
• another temporal duration;
• wherein
• said another temporal duration is indicative of time between said first occurrence and said second occurrence;
• and
• said first temporal duration is indicative of time between said first occurrence and said third occurrence, or
• said first temporal duration is indicative of time between said third occurrence and said second occurrence;
• said temporal relation being indicative of a proportion of a distance between two consecutive reference positions so as to indicate a position of the toe portion of the charge of material between said two consecutive reference positions;
• displaying, on a user interface, the generated data indicative of said temporal relation for enabling improved control of the position of the toe portion;
• receiving an input from a user to control or change a solid material feed rate after the generated data is displayed on the user interface;
• and
• controlling or changing a solid material feed rate based on said received input;
• wherein said solid material feed rate affects the position of the toe portion.

A system for generating information relating to an internal state of a tumbling mill having a shell that rotates around an axis at a speed of rotation for grinding a charge of material by tumbling the material in the rotating shell;

• said shell having an internal shell surface including a first number of protrusions configured to engage material as the shell rotates about the axis, thereby causing a mechanical vibration when a protrusion engages with a toe portion of the charge of material;
• said first number of protrusions being higher than one, the system comprising one or more hardware processors configured to:
• generate a time sequence of position signal sample values including a certain number of reference position signal values per revolution of the rotating shell;
• said certain number being equal to said first number of protrusions;
• detect a first occurrence of a first reference position signal value in said time sequence of position signal sample values;
• said first occurrence being indicative of a first rotational reference position of said rotating shell;
• detect a second occurrence of a second reference position signal value in said time sequence of position signal sample values;
• said second occurrence being indicative of a second rotational reference position of said rotating shell;
• generate a vibration signal dependent on the mechanical vibration;
• said vibration signal including a time sequence of vibration sample values;
• detect a third occurrence of an event signature in said time sequence of vibration sample values;
• generate data indicative of a temporal relation between
• said third occurrence, and
• said first and second occurrences;
• wherein said temporal relation is indicative of a position of the toe portion of the charge of material as a proportion of a distance between said first reference position and said second reference position;
• display, on a user interface, the generated data indicative of said temporal relation for enabling improved control of the position of the toe portion;
• receive an input from a user to control or change a solid material feed rate after the generated data is displayed on the user interface;
• and
• control or change a solid material feed rate based on said received input;
• wherein said solid material feed rate affects the position of the toe portion.