The innovative way to hear your grind.

An impactmeter measures the impacts of steel balls against the SAG mill liners, as well as ball-to-ball impacts and classifies them into critical impacts or standard impacts based on the intensity of each impact.

ImpactFinder is a field device that can be directly integrated to the plant DCS through any industrial network, and with a processing capacity to incorporate phenomenological models to estimate ball trajectory and internal mill load accommodation, functionalities that were not available as standard on the impactometers available on the market at that time.

System Architecture

ImpactFinder (IF) uses two industrial microphones, one on the loading foot side, where impacts are counted and classified, and one more on the loading shoulder side, with which the fill level is estimated.

Both signals are connected to the IF electronics for signal processing and are sent to the DCS through industrial Ethernet / IP communication, Profibus DP, Modbus TCP. The IF electronics is also connected via Ethernet / IP to the computer with the Advanced Visualization HMI proprietary of the system.

System Installation

In the image you can see the installation of the microphones, these must be installed at a distance between 35-45 cm from the mill hull and an angle of 35°.

We can also observe the control panel of the system, which must be at a distance no greater than 300 ft from the location of the microphones.


Sound level

It shows the trend of the magnitude of the sound in decibels (dB), which functions as an indicator of the mill fill level trends.


Indicates trend of change in filling levels

Immediate measurement of the internal state of the mill

Quality parameter for estimating the mill sound

Impact module

It classifies impacts through the configuration of two levels of intensity, with all those low levels classified as standard impacts and high levels classified as critical impacts.


Increased lifetime of liners

Control of grinding product size

Enable smart ball magazine

Fill level

It performs a measurement of the percentage of the internal filling with respect to the total volume of the mill, taking into account the variation of the apparent internal density. The display shows graphically the real-time status of the percentage fill level.


Decrease power variance

Stability in the entire process

Grinding product control

Risk reduction due to overfilling or lack of mineral

Cascade and loading angle module

It allows determining the exact point where the ore waterfall collides, as well as the angle of the load arrangement due to the mill’s turning speed. This module integrates an analytical model which is fed by process variables such as the pressure value of the mill bearings, mechanical dimensions of elevators, mill speed, among others, for the self-calibration of the measurement.


Monitoring of collisions on liners

Increased lifetime of liners

Enables load impact zone control

Control of grinding product size

Enables reduction of power consumption variance

Innovations at ImpactFinder

What is the main comparative advantage of ImpactFinder versus traditional impactmeters?

The main competitive advantage is the incremental innovation that we keep on the product:

  1. Ball path for three lift sections, where the wear is different.
  2. Reproduction in the control room of the sound picked up by the microphones.
  3. Scatter Plots in real time with three horizons of time, useful for detecting overload scenarios, regions of operation depending on the hardness of the mineral, behavior of impacts vs. the flow of water for different minerals. It is explained graphically some lines below.

System Maintenance

Increasing the availability of microphones is one of the challenges that impactmeter manufacturers have. Although the microphone we currently use is IP 67 (dust protection and submersible one meter in water for up to 30 minutes) it requires maintenance every 6 months and a recalibration for system gain adjustments on an annual basis.

Advanced Visualization

The system has a proprietary interface for advanced visualization, in which an image of the SAG mill with the trajectory of the ball and the load arrangement is shown in the center, in addition to the four calculation modules of the system:

Advanced visualization was incorporated into the equipment to cover the limitation that the DCS HMIs have in being able to display the trajectory of the ball and the load arrangement. The 4 calculation modules with the process variables that are measured, which are integrated by the industrial network to the DCS and which are displayed in this HMI.

Installed base


Minera Saucito I&II
2 ImpactFinder® systems


Mill Features

Diameter22 ft.

Length7 ft.

Capacity180 tph

Internal load25-38 tons

Motor1,300 kW

Control systemRockwell


Minera PenmontUnidad: “La Herradura”


Mill Features

Diameter28 ft.

Length11 ft.

Capacity370 tph

Internal load110-130 tons

Motor2,900 kW

Control systemDelta V


Minera Mexicana “La Ciénega”


Mill Features

Diameter20 ft.

Length9 ft.

Capacity170 tph

Internal load20-33 tons

Motor1,300 kW

Control systemFoxboro


Minera Escondida Ltd.
2 ImpactFinder® systems


Mill Features

Diameter40 ft.

Length29 ft.

Capacity6,667 tph

Internal load6,200-7,200 kPa

Motor20,500 kW

Control systemABB


Minera PenmontUnidad: “La Herradura”


Mill Features

Diameter30 ft.

Length12.6 ft.

Capacity650 tph

Internal load250-300 tons

Motor7,500 kW

Control systemRockwell


Asarco Mission South
2 ImpactFinder® systems


Mill Features

Diameter28 ft.

Length12 ft.

Capacity550 tph

Motor5,800 kW

Control systemRockwell


Minera Fresnillo


Mill Features

Diameter20 ft.

Length13 ft.

Capacity203 tph

Internal load580-680 psi

Motor2,000 kW