232 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
The use of the high-voltage electrical impulses passing
through the material offers the possibility of breakage into
the single constituents, which is attractive for mineral pro-
cessing applications. The separation of the minerals along
the grain boundaries is desirable and offers a variety of tech-
nological advantages.
In the 1990s, the work from Andres (Andres, 1989,
1995 Andres and Timoshkin, 1998) started to draw the
interest to potential applications. High-voltage impulses for
ore processing has been a topic of interest for the last thirty
years.
The introduction of laboratory commercial units,
which have found their way into many mineralogical and
geological laboratories worldwide, have contributed to the
dissemination of the technology and further interest on the
potential applications.
Intensive investigations with these units, particularly
by the researchers at the University of Queensland (UQ),
have confirmed potential benefits for pre-weakening and
improved ore recovery (Wang et al., 2011 Shi et al., 2013
van der Wielen, 2014 Zuo et al., 2015a Zuo et al., 2019).
Some other applications include the processing and recy-
cling of electronic components or concrete recycling (Bru et
al Martino et al., 2017 Bru et al., 2018 Pestalozzi, 2020).
Recently, the UQ research group has reported the develop-
ment of a new electrode design that allows an improved
pre-concentration (Lay et al., 2023). One of the main dis-
advantages of the laboratory units, however, is their lim-
ited capacity, which does not allow for practical industrial
application.
The need for the development of continuous operating
units is evident. The interest of the industry has grown and
the objective throughput in the range of tons per hour is
now driven by industrial funding (Cyrus, 2023). There are
only a few studies on continuous processing of materials
by means of high-voltage electrical impulses, mainly with
the PWTS equipment from Selfrag (Zuo et al., 2015b
Tschugg et al., 2017 Bru et al., 2020b Bru et al., 2020a) .
During the past few years a machine for the continu-
ous processing of materials based on the high-voltage elec-
tro impulse technology has been developed, constructed
and commissioned at the Institute for Mineral Processing
Machines and Recycling Systems Technology (IART) at
the TUBAF as a joint research project (Project 033R161,
funded provided by the German Ministry of Research
and Education-BMBF) (Anders et al., 2020). Further
research work on the machine has been conducted as a
part of a research project supported by the German Federal
Environmental Foundation (DBU Az: 35693).
While several ores and materials have already been
tested on the machine, only the initial results from continu-
ous testing of granodiorite and scheelite ore are presented
in this paper. Although investigations have been performed
on slags as well, the results cannot be disclosed due to a
confidentiality agreement in place.
In the following sections an overview regarding the
pilot machine development and its capacities is presented,
the experimental procedure, the material selection and
characterisation, and the results obtained from the initial
tests.
DEVELOPMENT OF A CONTINUOS
ELECTRICAL COMMINUTION MACHINE
The process leading to the construction of a continuously
working high-voltage electrical comminution machine was
accompanied by several stages including a proof of concept
with a small scale semi-continuously operating system to be
Figure 1. Electrical impulse applications and underlying working principle (Source: Anders/TUD-IMM)
The use of the high-voltage electrical impulses passing
through the material offers the possibility of breakage into
the single constituents, which is attractive for mineral pro-
cessing applications. The separation of the minerals along
the grain boundaries is desirable and offers a variety of tech-
nological advantages.
In the 1990s, the work from Andres (Andres, 1989,
1995 Andres and Timoshkin, 1998) started to draw the
interest to potential applications. High-voltage impulses for
ore processing has been a topic of interest for the last thirty
years.
The introduction of laboratory commercial units,
which have found their way into many mineralogical and
geological laboratories worldwide, have contributed to the
dissemination of the technology and further interest on the
potential applications.
Intensive investigations with these units, particularly
by the researchers at the University of Queensland (UQ),
have confirmed potential benefits for pre-weakening and
improved ore recovery (Wang et al., 2011 Shi et al., 2013
van der Wielen, 2014 Zuo et al., 2015a Zuo et al., 2019).
Some other applications include the processing and recy-
cling of electronic components or concrete recycling (Bru et
al Martino et al., 2017 Bru et al., 2018 Pestalozzi, 2020).
Recently, the UQ research group has reported the develop-
ment of a new electrode design that allows an improved
pre-concentration (Lay et al., 2023). One of the main dis-
advantages of the laboratory units, however, is their lim-
ited capacity, which does not allow for practical industrial
application.
The need for the development of continuous operating
units is evident. The interest of the industry has grown and
the objective throughput in the range of tons per hour is
now driven by industrial funding (Cyrus, 2023). There are
only a few studies on continuous processing of materials
by means of high-voltage electrical impulses, mainly with
the PWTS equipment from Selfrag (Zuo et al., 2015b
Tschugg et al., 2017 Bru et al., 2020b Bru et al., 2020a) .
During the past few years a machine for the continu-
ous processing of materials based on the high-voltage elec-
tro impulse technology has been developed, constructed
and commissioned at the Institute for Mineral Processing
Machines and Recycling Systems Technology (IART) at
the TUBAF as a joint research project (Project 033R161,
funded provided by the German Ministry of Research
and Education-BMBF) (Anders et al., 2020). Further
research work on the machine has been conducted as a
part of a research project supported by the German Federal
Environmental Foundation (DBU Az: 35693).
While several ores and materials have already been
tested on the machine, only the initial results from continu-
ous testing of granodiorite and scheelite ore are presented
in this paper. Although investigations have been performed
on slags as well, the results cannot be disclosed due to a
confidentiality agreement in place.
In the following sections an overview regarding the
pilot machine development and its capacities is presented,
the experimental procedure, the material selection and
characterisation, and the results obtained from the initial
tests.
DEVELOPMENT OF A CONTINUOS
ELECTRICAL COMMINUTION MACHINE
The process leading to the construction of a continuously
working high-voltage electrical comminution machine was
accompanied by several stages including a proof of concept
with a small scale semi-continuously operating system to be
Figure 1. Electrical impulse applications and underlying working principle (Source: Anders/TUD-IMM)