TH Georg Agricola

RAG Aktiengesellschaft, Essen/Germany, started to digitise abandoned surface openings, shafts and mining galleries of the coal mining sector via the Sigfox-0G network. There are around 60,000 in North Rhine-Westphalia alone. The aim of this IoT connection is the continuous monitoring of changes in real time in order to increase protection against sinkholes and reduce the effort of on-site inspections. The Sigfox–0G-based mining shaft monitoring system, which is also used for long-term documentation, has been designed by the Research Center of Post-Mining (FZN) and the Electrical Engineering/Information Technology and Industrial Engineering research sector of the TH Georg Agricola University (THGA) in Bochum/Germany and developed to series production in cooperation with the RAG (Figure 1).

The 0G-based remote monitoring system which is operated by a solar generator comprises pull-wire switches and a microcontroller with radio transceiver, which transfers the data via Sigfox-0G networks to a monitoring cloud. The sensors monitor, e. g., the vertical movement of the filling column of an old mine shaft. The data collected via Sigfox-0G network can be shown in the cloud for monitoring purposes and in the event of an alarm can be automatically sent to a predefined message chain by SMS and e-mail.

“It is necessary to constantly monitor the over 5,200 km² hard coal easements in our area of responsibility which have around 7,200 former surface openings because sinkholes are possible at any time in a section of around 100 km². Therefore, around 6,000 inspections are carried out every year in order to be able to take preventative action in good time. To minimise these on-site inspections and for real-time monitoring of any changes, selected surface openings are now also constantly monitored via a Sigfox-0G network connection”, says Frank Wollnik from the Site and Geo Services Division of RAG.

“The Sigfox-0G solution for shaft monitoring is an element of the so-called Mineberry system, which works completely independently and is solar-operated and is suitable for almost every type of old mining objects thanks to the modular structure. In order to implement the cloud connection of our remote monitoring solution in a manner that is cost-efficient, long-lasting and maintenance-free, we connected proven sensor technology to the innovative Sigfox-0G network. And as it can be used worldwide without any roaming charges, our solution can also be used worldwide”, explains Prof. Bernd vom Berg, Head of the Laboratory for Electrical Measurement and the Laboratory for Microprocessor Technology at the THGA.

“The RAG monitoring system is an excellent example of the remote monitoring of things and states, which up to now could not always be given special attention because it was too expensive or too energy-hungry to record all this data in real time. However, with Sigfox 0G real-time monitoring of even the simplest objects and states is possible. In the case of mining, it is easy to imagine that there are many control points worldwide, which can be monitored via a Sigfox-0G network. Especially because after the fossil-fuel phase-out no more money is earned, cost-efficient and low-maintenance data communication channels like Sigfox-0G offers are particularly important”, explains Stéphane Pâris, Technical and Network Director at Sigfox Germany.

The 0G controller is installed aboveground outside the possible Ex zone for the remote monitoring system for surface opening monitoring, whereas the Ex-protected sensors are installed in the shaft. As radio signals can be transmitted via the Sigfox-0G network across many kilometres, their use is also possible in areas with a poor mobile phone connection. The controllers can also be operated for many years without changing the batteries thanks to the battery-saving radio technology. Installations in the equally radio-critical underground environment can be found in the water supply network of the city of Antwerp. However, prerequisites for extensive underground installations are repeaters, which must be positioned every 3 to 5 km. (THGA/Si.)

On 15th May 2020, the TH Georg Agricola University (THGA), Bochum/Germany, appointed Kai van de Loo as honorary professor. Prof. van de Loo has already been passing his knowledge on to budding industrial engineers at the THGA for many years in his role as lecturer. From 1992 to May 2020, he worked for the German Coal Association (GVSt), Essen/Germany, in various functions and roles. In future, Prof. van de Loo will also be contributing his expertise to the Research Institute of Post-Mining (FZN) at the THGA.

RAG Aktiengesellschaft, Essen/Germany, tested methods for further reducing PCB in pit water at pilot facility level in Bergkamen and Ibbenbüren. The initial results from this series of tests are now available. The investigation into the PCB content takes place at the margin of detectability in the trace substance range. The analytical process being used here for the first time needs further development. At the same time, project manager Christoph Schabronath emphasises that: “The environmental quality standard for PCB in water is being adhered to at both the Haus Aden and Ibbenbüren sites.”

RAG broke new ground with this project and exceeded the legal requirements. Both the systems engineering and the analysis in the trace substance area were challenging. The task was to filter the smallest traces of PCB out of a large volume of pit water and to analyse it.

In North Rhine-Westphalia, RAG operated a pilot facility on container scale for removing PCB from pit water at the Haus Aden site, followed by Ibbenbüren (Figure 1). Further developed technologies and operating methods from drinking water preparation were used, i. e. single- and multi-layer filters made from quartz sand and anthracite coal in the pit water side stream.

Schabronath explains: “The pilot facility ran smoothly at both sites. However, the examination of the PCB content took place at the margin of detectability in the trace substance range.” Reliably determining such small traces of a substance and assessing the results is extremely challenging, and requires experience and a procedure adapted to the specific case at hand.

Due to the low concentration of PCB in the pit water, the results were unclear and it was not possible to eliminate uncertainty in the analysis. With such minimal traces, parallel investigations into the background presence of PCB in air and water are necessary.

At the end of 2019, an expert group consisting of ministries, authorities, surveyors and scientists met to assess these results. This group of experts also sees a need for further research. RAG has committed to further developing the analytical method within the framework of a doctorate in cooperation with the TH Georg Agricola University (THGA) in Bochum. (RAG/Si.)

The Haus Aden 2 shaft from RAG Aktien-gesellschaft, Essen/Germany, in Bergkamen is currently being filled. In 2023, submersible pumps are to pump mine water at depth through cladding tubes. The filling work will be completed by the end of the year. RAG has submitted the planning notification to North Rhine-Westphalia’s mining authority in order to raise and discharge mine water from the Haus Aden site into the Lippe river. RAG has provided an initial overview of the project in this planning notification, which makes the procedure transparent right from the start.

After coal mining has ended, the long-term optimisation of mine water drainage is a central element of the perpetual obligations. The mine water plan for the Ruhr region envisages that, in the future, the mine water will only be raised at six central water drainage sites. Haus Aden in Bergkamen is one of these future central water drainage sites.

No mine water is currently being raised at Haus Aden. The site is currently being converted into a well drainage system (Figure 1). For this purpose, Thyssen Schachtbau, Mülheim an der Ruhr/Germany, is building three cladding tubes in the shaft. This happens step by step. First of all, the tubes are constructed section by section and then the corresponding shaft section is filled with concrete. Work started at the end of September 2019. At present, approximately 120 m of concrete has been poured – a total of around 5,000 m³ of concrete. The remaining 660 m should be completely filled by the end of the year and the pumps should be operational by the end of 2023.

RAG expressly supports the Water City project in its planning work. As a result, a new functional building based on a harmonious and coordinated overall plan is also to be jointly turned into an architectural landmark. RAG is planning a power house at the site, which will contain a well system with lifting equipment for the pumps and pipelines that, in the future, will regulate the mine water level in the eastern Ruhr region. Preserving the shaft frame is not compatible with these plans. The power house will not fit under the existing construction. Instead, it is to be built on the dismantled shaft frame foundation in order to transfer the huge total load of the lifting equipment and the three suspended pipelines, each weighing 500 t, into the ground. This is the latest point at which the remaining steel construction’s statics can no longer be guaranteed.

In order to resume drainage after the target horizon has been reached, RAG requires a new permit relating to water laws in order to raise and discharge mine water into the Lippe river. The planning notification marks the start of the water law procedure, which also includes an Environmental Impact Assessment (EIA). This planning notification has meanwhile been sent by the mining authority to authorities, associations, communities and other public bodies. The mining authority will soon invite these recipients to a scoping meeting. At this meeting, the content and scope of the documents submitted by RAG in the water law procedure requiring an EIA will be discussed.

The water law procedure will also deal with the issue of removing traces of PCB present in mine water. To investigate the extent to which it is possible to separate these traces from the mine water, RAG already began operating container-scale pilot facilities at the Haus Aden and Ibbenbüren sites about a year and a half ago to filter out the smallest traces of PCB from a large quantity of mine water and examine them analytically. The pilot facility ran smoothly at both sites. At the end of 2019, the results were evaluated by an expert group consisting of ministries, authorities, RAG, IWW, surveyors and scientists. Since this group of experts also sees a need for further research – especially in the field of analytics – RAG has committed to further developing the analytical method within the framework of a doctorate in cooperation with the TH Georg Agricola University (THGA) based in Bochum/Germany. (RAG/Si.)

The Technical University Georg Agricola (THGA), Bochum/Germany, appointed Peter Schrimpf as honorary senator for his excellent accomplishments as patron of the university. A special honour was bestowed on the CEO of RAG Aktiengesellschaft and long-standing Chairman of the University Council. He is only the third honorary senator in the university’s history – the title was last awarded in 2002.

Research should be application-oriented? And directly improve the life of people and the environment? The projects of Prof. Bernd vom Berg could hardly have any more practical relevance. The expert on electrical engineering and information technology at the Technical University Georg Agricola (THGA), Bochum/Germany, develops intelligent systems, which benefit Bochum directly, and also the animal inhabitants. He was awarded the first Third Mission Award from the university for his innovative ideas and social commitment (Figure 1).

With “Third Mission” the THGA describes its mission to link civil society and companies more closely with the university and promote the transfer of knowledge – alongside its core activities of research and teaching. The Third Mission includes cooperation projects with partners outside the academic landscape or initiatives, which should inspire the so-called “pioneers” for an academic education. Due to its application-oriented focus, the THGA is very active here. But last year Prof. vom Berg was the most active on the “Third Mission”.

With his team he developed a special monitoring system, which was originally designed to monitor legacies of the mining industry. A good deal more has now come out of it. The “Hai-Tech” system now also controls and protects large aquariums and terrariums in Bochum Zoo, with whom the THGA has been successfully cooperating for several years. More zoos throughout Germany are to be added in the future.

Prof. vom Berg was also able to find many more interesting locations for his technology solutions nearby. The sensors made by THGA are currently attached to a Bochum game reserve and monitor wild boars and similar animals. For this, the lecturer works closely with students from the Schiller School. And even the pond in Bochum city park cannot manage without the equipment of the electrical engineering professor. Here in the local recreation area Prof. vom Berg continuously checks the water quality and advises the city of Bochum on water management and monitoring.

“Excellent projects like these show how the applied research of the THGA works in urban society over the long term and what opportunities arise from it for further cooperation”, said Provost Prof. Jürgen Kretschmann at the award ceremony. “We want to continue to actively stimulate this dialogue between university and society and therefore honour special commitment in the future with a separate award, which will now be awarded every year.” (THGA/Si.)

A total of 70 leading industry representatives – managing directors, sales directors, association representatives and representatives of IGBCE and the NRW mining authority – met on 26th September 2019 at the former Zeche Zollern (colliery) in Dortmund/Germany for the fifth annual conference of the Mining Industry Network of the EnergieAgentur.NRW, Düsseldorf/Germany (Figure 1).

It was also an opportunity to examine current target markets as 97 % of services, machines and systems are exported. The raw materials industry around the world faces diverse and demanding challenges. Sustainable market and sales visions are sought and visionaries to promote them. What is important and what will become important? The network coordinated and moderated the event on behalf of the Ministry of Economic Affairs of the State of North Rhine-Westphalia. The contributions showed the whole spectrum of the industry activities and market developments through to the high level of innovation of the supplier industry in North Rhine-Westphalia in the raw materials segment. After the end of coal mining the know-how and expertise established here and appreciated worldwide continue to be promoted on international markets such as Chile, China, Russia, Turkey or Africa. Apart from the classic use, it is necessary to show applications in the hard rock mining sector, ore mines, salt and rare earth fields, as well as in tunnel construction, around the world for the companies. Complex technical solutions and the high degree of specialisation, specially in the areas of digitisation, occupational safety, accident prevention and environment protection, offer opportunities, which are seized and supported also with the help of the EnergieAgentur.NRW. Harmonisation, coordination and moderation are effected in many cases in close collaboration with VDMA Mining, the Technical University Georg Agricola (THGA), institutes of the RWTH Aachen University, the DMT GmbH & Co. KG or other partners from Germany or abroad. Many regions in the world rich in raw materials benefit from this sustainable approach of the NRW experts and their knowledge. Because one thing is clear: The know-how and expertise of the specialist companies in North Rhine-Westphalia are at a superior international level and without mining there is no energy revolution or electric mobility. (EnergieAgentur.NRW/Si.)

What might mining look like in the future? How should the post-mining era be shaped? And how can raw material extraction, post-mining and sustainability be interlinked? These topics were considered by the Society of Mining Professors (SOMP), who met in Bochum/Germany from 1st to 4th July 2019 for the “Glückauf Future” conference (Figure 1). Around 110 renowned scientists from around the world exchanged their experiences at the Georg Agricola University of Applied Sciences (THGA). They had been invited by THGA President Prof. Jürgen Kretschmann, who is currently SOMP President and thus the head of the world’s leading professional association of mining industry sciences for one year.

As part of the conference, the experts reflected on concepts for modern and future-oriented mining in lectures and discussions. They also considered how disused mines can be secured and how industrial and urban landscapes can be successfully restructured. The participants were able to survey some successful real-life examples of regional structural change first-hand during excursions. The conference at the THGA was supported by the RAG Foundation, Essen/Germany. “Mining in the Ruhr area not only generated coal, but also wealth, technology, science, education, social life and culture,” said Bärbel Bergerhoff-Wodopia, member of the board of the RAG Foundation, when welcoming the international delegates. “High-level technical skills have been developed here for over 200 years. The Ruhr area is now becoming a hub of post-mining knowledge.”

In the past year, the mining experts have already met in Bochum to discuss “technological footprints in the German coal mining industry”. This year, the conference was dedicated to the future of mining and to the “After”. German academics and the THGA, with its post-mining research centre, which is unique in the world, are pioneers in both of these fields. “We draw on our research and on the experiences of the Ruhr area to support mining regions across the world to optimise socio-ecological conditions and to minimise the dangers to the soil, water, air and people.

The roots of the SOMP can be traced back to the 18th century. Its predecessor, the “Societät der Bergbaukunde” was founded in 1762 by mining experts from 21 countries. Mining science was developing rapidly during this period and the exchange of ideas became important as a driver of progress. One honorary member of that era: Johann Wolfgang von Goethe.

The name of the present “Society of Mining Professors/Societät der Bergbau-kunde”, founded in 1990, is clearly intended to establish it as a direct descendant of its predecessor. The principal objective, both then and now: to secure and exchange the scientific and technical knowledge necessary for a sustainable supply of minerals for humanity. The Society currently numbers 287 researchers from 45 countries. They represent 178 research institutions from all around the world. SOMP is thus the world’s leading professional association for mining industry sciences. Their annual meeting is the most important event in mining industry research internationally.

Post-mining is “Research for Eternity” and is particularly closely aligned with the UN Sustainable Development Goals (SDGs). There is enormous potential, especially for the implementation of the UN SDGs of affordable and clean energy, decent work and economic growth and industry, innovation and infrastructure. Where we once produced coal, we can now generate renewable energy. In the Ruhr area, there are numerous examples of how tips and former colliery sites can become commercial, residential and leisure areas. At the research centre, an interdisciplinary team is focusing in particular on research in the areas of geomonitoring, materials sciences, environmental technology and geoecology as well as into the corresponding future potentials,. Their findings are feeding into areas including e. g. mine water management by RAG Aktiengesellschaft, which is being technically implemented in a new mine water control room at the former Pluto mine in Herne. (THGA/Si.)

He has dedicated his working life to mining and post-mining, and has cultivated international partnerships as well as the next generation of scientists: For his dedication, Prof. Jürgen Kretschmann, President of the Georg Agricola University of Applied Sciences (THGA), Bochum/Germany, has now been honoured with the Günter Fettweis Award. The prize is awarded by the Society of Mining Professors (SOMP), the world’s leading professional association for mining industry sciences, of which Prof. Kretschmann was Chair for a year in 2018 (Figure 1). The association honours active members who have made a particular specialist contribution to the SOMP with this international award. The prize primarily celebrates excellence in teaching and research which promotes mining as a scientific discipline.

The distinction is named after Günter B. Fettweis, Professor of Mining Sciences in the Department for Mining Sciences, Mining Technology and Mining Management at the Montan-universität Leoben/Austria, who passed away in 2018. In 1990, Fettweis re-established the SOMP in line with its historical predecessor and also became the first President of the re-founded society. He was considered a role model by both students and specialist colleagues thanks to his enthusiasm for his subject.

This is just one of the reasons why Prof. Fettweis and Prof. Kretschmann – the namesake of the award and its winner – have a lot in common. Both studied in Aachen, “lived and taught” mining internationally and have driven academic education in the mining sector. “I am very happy to be the first German recipient of this important honour from the most renowned academic association in mining in the world,” said Prof. Kretschmann at the award ceremony. “It is also an honour for my university. The THGA has an excellent reputation worldwide. It stands not only for outstanding practice-oriented engineering education, but is also the leading university of applied sciences in Germany in the fields of raw materials sciences and post-mining. Here, we are working together with renowned universities as equals.”

Prof. Kretschmann studied Economics at Aachen, Bochum and Dortmund and completed his doctorate in 1990 at Göttingen. His postdoctoral qualification followed in 1998 at the RWTH Aachen University in the field of Georesources and Materials Technology, where he then became a lecturer. From 1990 until 2001, Kretschmann held various positions at RAG Aktiengesellschaft. He has been Chair of the Management Board of the DMT Gesellschaft für Lehre und Bildung mbH and simultaneously President of the THGA since 2006. Prof. Kretschmann is also a member of numerous national and international specialist associations and was recently President of the SOMP (2018/19). (THGA/Si.)

Fourteen budding engineers for raw material extraction from the TH Georg Agricola University in Bochum/Germany visited WESTKALK’s Kallenhardt plant on a study trip (Figure 1). They were accompanied on their excursion by a drone, which documented the university group’s activities with a photo flight.

Nowadays, drones are used for surveying, which is required in quarries for their annual mass calculation, to enable precise calculation of the fractional interest rate for the lessors and the product stock for inventory purposes. WESTKALK does not currently use drone surveys. The THGA university groups’ excursions now regularly involve drone flight documentation, says excursion leader Prof. Albert Daniels.

As part of their quarry visit, the stu-dents learnt about the geology of the compacted Devonian lime and the large-scale technology used at the Kallenhardt plant. Even three years after commissioning, the crushing plant, with its combination of drum screening and impact mill, is unique in Germany. The project was funded by the Federal Environment Ministry.

The WESTKALK pilot project contributes to an improved use of deposits and therefore to a significantly reduced land use – as the Federal Environment Ministry stated in a press release at the time. The argillaceous substances are first crushed in a drum screen and then filtered out. The pre-screening material produced is cleaned in the stone washing plant to process the limestone it contains into marketable products. Owing to the improved separation of valuable rock and waste material, blasted raw material heavily mixed with clay can be transported to the crushing plant. That reduces the proportion of unused valuable rock on the spoil tip from around 30 to less than 5 %. The resulting increase in the usage rate of the deposit leads to an almost optimal raw materials efficiency. (WESTKALK/Si.)