XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 533
particle size ranges were tested, 30 to 50 µm, 75 to 110 µm,
220 to 280 µm, and 300 to 350 µm. Ballotini particles
were bought from VWR company, supplied from Sigmund
Lindner GmbH. Poly (Methyl Methacrylate)
Data Collection and Analysis
For single particle experiments, the trajectory of the particle
is recorded by high-speed camera. Any positions of particle
varied with time can be extracted accurately. The quanti-
tative data from the trajectories are average velocity and
levitation height. In addition, the particle motion modes
and travel direction are important, which are collected as
qualitative data.
The frames extracted from the high-speed camera were
further analyzed by image processing software Tracker. The
particle in the frames can be identified based on the pixel
features of each point and its surroundings automatically.
If the image is not clear, the point can also be manually
identified. The marked positions are recorded on each
frames, shown as purple circles in Figure 7, and therefore,
the variation of position with time is obtained. The result
was recorded in the sheets shown in the right columns of
Figure 7.
For multiple particle experiments, the data collection
includes the size distribution and mass balance in the for-
ward and backward directions. In the experiment, the mass
of particle being used to assess their transport is measured
before initialising the ETW system. The initial state of the
particles is set up by having a mass (mi) of particles are slowly
released to free-fall from a plastic petri dish at a height of
10 mm above the board and land on the surface in the mid-
dle of the platform. When activated, the system transports
the particles across the surface to be collected in the con-
tainers on each end. The mass of the collected particles in
the forward direction and backward direction are weighed
and recorded as mf and mb. In the experiment, the mass of
the particles remaining on the board was also measured and
recorded as ms. Because a few particles may be transported
away from the edges of the board, the sum of mf, mb and ms
is slightly smaller than 100%. The forward and backward
recovery rate is calculated as Rf= mf/mi and Rb= mb/mi,
respectively. The sum of mf, mb and ms represents the total
particles that can be controlled. Controlled particles refer
to the particles that can be manipulated, either by collect-
ing them in the forward or backward direction or remain-
ing on the board. After the mass measurement of collected
Figure 7. Software User Interface: the top row is the software’s functionality area to open and save file. The second top row
involves the scale calibration and particle tracking function
particle size ranges were tested, 30 to 50 µm, 75 to 110 µm,
220 to 280 µm, and 300 to 350 µm. Ballotini particles
were bought from VWR company, supplied from Sigmund
Lindner GmbH. Poly (Methyl Methacrylate)
Data Collection and Analysis
For single particle experiments, the trajectory of the particle
is recorded by high-speed camera. Any positions of particle
varied with time can be extracted accurately. The quanti-
tative data from the trajectories are average velocity and
levitation height. In addition, the particle motion modes
and travel direction are important, which are collected as
qualitative data.
The frames extracted from the high-speed camera were
further analyzed by image processing software Tracker. The
particle in the frames can be identified based on the pixel
features of each point and its surroundings automatically.
If the image is not clear, the point can also be manually
identified. The marked positions are recorded on each
frames, shown as purple circles in Figure 7, and therefore,
the variation of position with time is obtained. The result
was recorded in the sheets shown in the right columns of
Figure 7.
For multiple particle experiments, the data collection
includes the size distribution and mass balance in the for-
ward and backward directions. In the experiment, the mass
of particle being used to assess their transport is measured
before initialising the ETW system. The initial state of the
particles is set up by having a mass (mi) of particles are slowly
released to free-fall from a plastic petri dish at a height of
10 mm above the board and land on the surface in the mid-
dle of the platform. When activated, the system transports
the particles across the surface to be collected in the con-
tainers on each end. The mass of the collected particles in
the forward direction and backward direction are weighed
and recorded as mf and mb. In the experiment, the mass of
the particles remaining on the board was also measured and
recorded as ms. Because a few particles may be transported
away from the edges of the board, the sum of mf, mb and ms
is slightly smaller than 100%. The forward and backward
recovery rate is calculated as Rf= mf/mi and Rb= mb/mi,
respectively. The sum of mf, mb and ms represents the total
particles that can be controlled. Controlled particles refer
to the particles that can be manipulated, either by collect-
ing them in the forward or backward direction or remain-
ing on the board. After the mass measurement of collected
Figure 7. Software User Interface: the top row is the software’s functionality area to open and save file. The second top row
involves the scale calibration and particle tracking function