# US 2014/0150524 A1 · Real-Time Monitoring System to Determine Wear of Grate Ribs in Semi-Autogenous Mills, to Detect Clogging Conditions of the Grates During the Operation and to Detect Working Conditions Under Direct Impact of the Balls on the Grates > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0150524 A1 - Document ID: US20140150524A1 - Status: Published application - Kind: A1 - Application number: 13/916,302 - Filed: 2013-06-12 - Published: 2014-06-05 - Earliest claimed: 2010-12-14 - Assignees: Universidad de Santiago de Chile - Applicants: Universidad de Santiago de Chile - Inventors: Luis MAGNE; Gilda Titichoca; Eduardo Altamirano; German Sepulveda; Marcelo Vasquez - Web page: https://patentgrep.com/patent/US20140150524A1 ## CPC - B02C 17/1805: {Monitoring devices for tumbling mills} - B02C 17/22: Lining for containers - G01N 29/12: by measuring frequency or resonance of acoustic waves {(measuring frequency or resonant frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04, G01H13/00; acoustic resonators G10K11/04; vibration or shock testing of structures G01M7/00)} - B02C: CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN ({household tools and machines for pulverising foodstuffs, e.g. coffee and spice mills A47J42/00; pharmaceutical mortars A61J3/02; mechanical processing of refuse and garbage B03B9/06; dressing mould materials by grinding B22C5/04}; obtaining metallic powder by crushing, grinding or milling B22F9/04; {recovery of plastics by disintegrating B29B17/00; crushing raw materials in starch making C08B30/02; beaters for papermaking D21D1/02; crushing devices specially for transport in mines E21F13/002; slag crushing devices F23J1/00; fuel milling devices in combustion apparatus F23K1/00; household devices for crushing coal F24B15/02; ice disintegrating devices F25C5/02}) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract A real-time monitoring system to monitor the wearing in the thickness of the ribs of a grate of a SAG mill. The grate can have a screening surface that includes a pulp lifter and an external surface that is not exposed to impacts, and can also include a central trough where the supporting elements fit and which allow securing the grate inside the mill through fitting bolts. The system can comprise: a sensor (accelerometer or strain gage) located on the external surface in which the sensor is connected to a sensor adaptor unit; a wireless transmitter connected to the sensor to transmit the signal from the sensor; a wireless receiver for receiving the signal from the wireless transmitter; and a signal reader connected to the wireless receiver which processes the signals received from the sensor. ## Claims ### Claim 1 A real-time monitoring system to monitor the wearing in the thickness of the ribs (5) of a grate (1) of a SAG mill (9) due to the abrasive action of the ore pulp residing inside the mill and due to the action of the grinding elements during the operation, and which in certain cases also generates obstruction of the slots (4) due to the jamming of said grinding elements inside the slots (4) while the mill is running, and said grate (1) has a screening surface (2) that includes a pulp lifter (3) and an external surface (7) that is not exposed to impacts, and also includes a central trough (6) where the supporting elements fit and which allow securing the grate inside the mill through fitting bolts (12), WHEREIN said system includes: a sensor (16) placed on the external surface (7), wherein said sensor (6) is connected to a sensor adaptor unit (17); a wireless transmitter (18) connected to said sensor (16), wherein said transmitter outputs the signal from the sensor (16); a wireless receiver (20) for receiving the signal from the wireless transmitter (18); and a signal reader (21) connected to said wireless receiver (20) to process signals received from the accelerometer. ### Claim 2 (depends on 1) The monitoring system set forth in claim 1, WHEREIN said sensor (16) is an accelerometer. ### Claim 3 (depends on 1) The monitoring system set forth in claim 1, HEREIN said sensor (16) is a strain gage. ### Claim 4 (depends on 1) The monitoring system set forth in claim 1 WHEREIN said sensor (16), said sensor adaptor unit (17), and said wireless transmitter (18) are all connected to a timer (19) which defines a time interval to issue the signals from the transmitter. ### Claim 5 (depends on 1) The monitoring system set forth in claim 1 WHEREIN said signal reader (21) is a PC with signal reader software. ### Claim 6 (depends on 1) The monitoring system set forth in claim 1 WHEREIN the signal from the accelerometer (16) is conveyed by wiring (23) located on the external surface (7) of the grate (1), wherein said wiring (23) reaches the trough (6) of the grate (1) to then enter the chamber (15) located on the supporting elements (22), wherein said wiring (23) connects the wireless transmitter (18) placed in a bolt (12) on the cover (11) of the mill (9), and wherein the wireless signal is output to the wireless receiver (20), where the signal is processed by a signal reader (21). ### Claim 7 (depends on 2) The monitoring system set forth in claim 2 WHEREIN the signal from the sensor (16) is conveyed by wiring (23) located on the external surface (7) of the grate (1), and said wiring (23) reaches the trough (6) of the grate where the wireless transmitter (18) is placed, and the wireless signal is output directly to the wireless receiver (20), where the signal is processed by a signal reader (21). ### Claim 8 (depends on 6) The monitoring system set forth in claim 6 WHEREIN said wireless receiver (20) is placed in a safe area outside the SAG mill at a distance of approximately 20 meters from the mill. ### Claim 9 (depends on 4) The monitoring system set forth in any of the claim 4, WHEREIN the external surface (7) of the grate (1), wherein the bore (8) has a sufficient depth as to accommodate a magnet (24) on its bottom part thereof and on to allow placing of a rubber (25) over the magnet (24) as to allow magnetic force to be exercised and, therefore adhesion of the sensor to the magnet (24) as to securely affix the grate to the accelerometer. ### Claim 10 A method to calibrate the real-time monitoring system to monitor the wearing in the thickness of the ribs (5) of a grate (1) of a SAG mill (9) due to the abrasive action of the ore pulp residing inside the mill and due to the action of the grinding elements during the operation, and which in certain cases also generates obstruction of the slots (4) due to the jamming of said grinding elements inside the slots (4) while the mill is running, and said grate (1) has a screening surface (2) that includes a pulp lifter (3) and an external surface (7) that is not exposed to impacts, and also includes a central trough (6) where the supporting elements fit and which allow securing the grate inside the mill through fitting bolts (12), WHEREIN said method includes the following stages: a) Submitting the ribs (5) of the grate (1) to impacts using a ball (26) that is used in the mill (9), wherein the vibration produced by the impact is registered by the sensor (16) which transmits the signal captured to a sensor adaptor unit (17) and to a wireless transmitter (18), and said transmitter outputs the signal that is received by a wireless receiver (20) connected to a signal reader (21). b) Recording the signal using the signal reader (21); and c) Correlating said signal with the rib thickness (5). ### Claim 11 (depends on 10) The method to calibrate a monitoring system set forth in claim 10, WHEREIN stage a) consists of using a tube (25) with a diameter which is slightly greater than the diameter of the ball (26), which in said tube (25) is placed in a vertical position to the grate located outside of the mill, and the lower part of said tube (25) is in contact or is slightly located above the rib surface and the ball is placed on top of the tube where it falls through it (26). ### Claim 12 (depends on 11) The method to calibrate the monitoring system set forth in claim 11, WHEREIN said tube is made of plastic material. ### Claim 13 (depends on 11) The method to calibrate a monitoring system set forth in claim 11 WHEREIN it further consists of the stage d) of installing the calibrated grate in the mill. ### Claim 14 (depends on 10) The method to calibrate the monitoring system set forth in any of the claim 10 WHEREIN the sensor is an accelerometer. ### Claim 15 (depends on 10) The method to calibrate the monitoring system set forth in any of the claim 10 WHEREIN the sensor is a strain gage.