RAG

Backfilling of shafts XII and 2 on the grounds of the Zollverein World Heritage Site in Essen/Germany began in spring 2023. The shaft work is now being completed (Figure 1). In consultation with authorities, politicians and scientists, RAG Aktiengesell­schaft, Essen, has developed a concept for the long-term optimisation of mine water management in the Ruhr area. To this end, water management in the Ruhr area will be concentrated at six locations. However, the Zollverein site will remain part of the overall concept. The shafts serve as reserve locations in case the mine water does not overflow into the Prosper Haniel mine building on its way to the Rhine in the next stage, as expected. Zollverein thus combines monument and tradition with the classic tasks of post-mining. And it does so in the middle of a world cultural heritage site that is visited by tens of thousands of people from all over the world every year.

A few figures: Shaft 2 has a diameter of 5.5 m, Shaft XII 7.50 m. They extend from the surface to a depth of approximately 1,050 m. For backfilling, formwork platforms were installed at both shafts above the 14th level at a depth of approximately 1,000 m. These formed the basis for the subsequent backfilling. Before that, the lowest part of the shaft, the so-called shaft sump, was filled with concrete. It serves as the foundation for the steel structure of the formwork platforms. The height of the level itself, approximately 5 m, remains free so that any mine water can be collected there in the future.

To ensure that the shafts remain stable in the long term, casing pipes were installed in sections, aligned and concreted in place so that submersible pumps can be lowered vertically through the pipes into the depths if necessary. For this purpose, three casing pipe strings were installed in shaft XII and two casing pipe strings in shaft 2. More than 20,000 m³ of concrete was required for shaft 2 and almost 39,000 m³ for shaft XII. The concrete column also ensures the long-term stability of the shaft.

Before the backfilling work could begin, numerous shaft installations – including those above ground – had to be dismantled. They were removed, professionally stored and will now be reinstalled in accordance with conservation guidelines after backfilling. This was done in close coordination with the Düsseldorf district government and the Zollverein Foundation.

The backfilling of the two shafts at the World Heritage Site presented RAG with major challenges. The work took place on a site with numerous residents and thousands of visitors in the vicinity of the shafts. Disruption to residents and visitors was kept to a minimum. The transport and pouring of the concrete, e. g., took place in soundproof lightweight halls. The work after backfilling will be just as challenging. Ultimately, the entire shaft complex must look exactly as it did before – with every screw in its original place.

Incidentally, the entire underground shaft filling work was completed without any accidents.This is further proof of the exemplary approach to occupational safety within the company and its partner companies.

“The Zollverein site with shafts 2 and XII is a very special location for us. Nowhere else is mining culture as alive as it is here. But Zollverein is also an active post-mining site. The site is home to the RAG-Stiftung, RAG and RAG Montan Immobilien. And Zollverein is also an important location for the implementation of RAG’s mine water concept. This combination of mining culture and active post-mining tasks is unique in the world and makes the site so exciting,” says Peter Schrimpf, CEO of RAG.

“Thanks to the meticulous preparation of the planned construction processes, the pre-assembly of all components above ground and close daily coordination, the technical closure of the Zollverein mine and the construction of the well structure were completed smoothly,” says Stefan Roßbach, Head of Department at RAG Mine Water Management. (RAG/Si.)

The official approvals and permits for the deconstruction of the surface facilities of the Auguste Victoria 8 mine in Marl/Haltern, Germany, have now been obtained (Figure 1). The preservation order will be observed.

“The deconstruction work is scheduled to start at the end of February 2025 and is expected to take 15 months,” says RAG project engineer Ulrich Ostrawsky. The upper monument authority (Ministry for Homeland, Municipal, Construction and Digitalisation of the State of North Rhine-Westphalia) has classified the hoist building, the shaft hall and the headframe as monuments. Therefore, they are not part of the demolition of the shaft site that now has begun. RAG Aktiengesellschaft, Essen/Germany, is currently trying to find a solution for these three operating facilities that will enable the mining authority to terminate its supervision of the entire site in the near future.

When coal mining at the Auguste Victoria mine was discontinued in 2016, hard coal mining in the central Ruhr area north of the Lippe river also came to an end. Shaft AV 8 was filled in during 2017. The surface facilities are to be dismantled and the open spaces unsealed in accordance with the final operating plan. In the future, the area will be used as a backup location for mine water drainage. (RAG/Si.)

RAG Aktiengesellschaft, Essen/Germany, has been monitoring the groundwater in the area of the Brinkfortsheide spoil tip since mid-2020 (Figure 1). A pumping test is now starting to plan a groundwater treatment plant.

Ten of the 13 additional groundwater measuring points planned have already been sunk and integrated into the monitoring system. All of them are in the south-western and north-western part of the spoil tip because this is where the groundwater flows under the spoil tip body from east to west. The last three were completed by the end of February 2025. The results of the measurements will be sent to the district government as agreed.

In addition, a pumping test of the groundwater will be carried out to determine the hydraulic design data for the planning of a future stationary groundwater treatment plant. During the three-month pumping test, the groundwater will be cleaned in a mobile treatment plant and then fed into the municipal sewer.

The measure has been agreed and approved by both the district government and the city of Marl.

(RAG/Si.)

It is quite hot inside the Graf Moltke waste dump. Temperatures of up to 450 °C have been measured at times. The reason for this is a smouldering fire that RAG Aktiengesellschaft, Essen/Germany, has been tackling with extensive clean-up measures since 2022. Now the second construction phase is beginning – as part of the final operation plan (Figure 1). After completion of the work, the Gladbeck landmark is to be handed over to the Ruhr Regional Association as a place for leisure and as a habitat for flora and fauna.

In 2022/23, the Wittringer Mühlenbach was piped over a length of approximately 180 m. In addition, specialists applied an approximately 7 m high embankment. In the second phase of the waste dump remediation, which is now to follow, around 300,000 t of soil masses will have to be moved. These serve to stabilise the embankment, to seal the waste dump body up to the top of the waste dump against further oxygen ingress and to cover it.

“We expect the construction work to take between twelve and fourteen months,” says project engineer Ulrich Ostrawsky. As before, the heap will continue to be monitored to verify the success of the clean-up. “The temperature drop in the “hot” areas will certainly take more than another ten years.” In this context, Simone Konzelmann-Krause, head of RAG’s remediation management, emphasises: “RAG continues to bear responsibility for the ongoing groundwater remediation, the groundwater and the necessary monitoring of the heap fire as part of its perpetual obligations.”

The Graf Moltke waste dump is located in the urban area of Gladbeck, in the immediate vicinity of the B224 federal highway and the A2 motorway. It is bordered by the Kösheide and Welheimer Mark streets to the south, the Brauck industrial park to the north and the Wittringer Mühlenbach stream to the west. This meant that the remediation of the mine dump fire took place in a very confined space, and the expansion of the B224 to the A52 motorway still had to be taken into account in the planning. (RAG/Si.)

In recent decades, RAG Aktien­gesellschaft, Essen/Germany, has actually only known one direction: closure of shafts, socially acceptable staff reductions. In this context, the company also had to discontinue its training activities at the end of 2018. Until then, RAG had given over 100,000 young people a career perspective. The company has now completed its strategic realignment from a former coal producer to a responsible shaper of the post-mining era. The company needs experts for this demanding job again. And it will also be providing training again from 2025 (Figure 1). Peter Schrimpf, CEO of RAG: “This is a clear signal. We have mastered the company’s transformation process and are looking to the future with optimism. And we want to shape the future with young people again.”

The company’s mission is to improve the quality of life in mining regions – day after day. In doing so, RAG acts responsibly towards people, the environment, the climate and finances. The tasks are demanding: They involve securing mining sites and developing former mining land into sites for the future and, of course, the perpetual task of mine water management. This involves intelligent solutions for making increasing use of the potential of mine water. And it involves operating the pumps in an environmentally friendly and efficient manner. RAG aims to become CO₂ neutral by 2030.

The company applies outstanding specialist and expert knowledge from various disciplines to accomplish these tasks sustainably. The company currently employs around 600 people. However, many of them will retire in the next few decades. RAG is therefore already focusing on recruiting activities again – around 20 new employees from various fields have already been hired. Schrimpf: “And since we ourselves know best what we need, we now want to offer young people exciting prospects with a solid education.”

“It is important to us that young people also start their careers in an optimal environment,” says Susanne Hardies, Chairwoman of the RAG Group Works Council. “In mining, one thing has always been true: You can rely on each other, both above and below ground, and for all generations,” says Hardies. Mining is associated with a sense of responsibility, reliability, commitment, solidarity and cooperation. “We want the new apprentices in the post-mining era to experience this too!”

Of course, the retraining programmes have also changed with the company’s realignment. Particular emphasis should be placed here on one occupation that is certainly not an everyday occurrence in the field of training and which also shows how exciting the topics of post-mining are at RAG. This is the occupation:

Environmental technologist for wastewater management

During the training, the focus is on the maintenance and servicing of systems, pumps and machines – including electrical engineering work – at RAG’s water management sites. The training offers insights into monitoring the rise of mine water using RAG’s modern control centre. It also covers water treatment and processing, as well as the analysis and evaluation of water samples. Trainees also learn how to handle raw materials, auxiliary materials and hazardous substances. In addition, the training offers insights into sustainable energy generation and efficient energy management.

Further apprenticeships will be offered in the following areas:

Digitalisation management assistant

Here, apprentices will find modern IT in an exciting company. The young people support the further development of digital business processes. They determine and coordinate the need for new and innovative IT solutions. Together with the specialist departments, they take care of data/IT security and data protection measures and ensure compliance with them. The focus is on the digital transformation of the company in a digital society.

Office management assistant

During their training, apprentices support the commercial and technical areas of the company and learn everything about the processes in an office. They communicate with internal and external partners, organise appointments, conduct correspondence, conduct research and create presentations. They learn how to use various digital applications. During the training, the focus is on specialising in two of the four main areas: “Order Control and Coordination”, “Commercial Control and Monitoring”, “Human Resources” and “Public Relations”.

Training starts in August 2025, with applications accepted from mid-September 2024. Further information is available on the website: www.rag.de/ausbildung. (RAG/Si.)

On 31th December 2005, the Lohberg mine belonging to RAG Aktiengesellschaft, Essen/Germany, was closed down. Around 1,400 employees were transferred to other mines or took early retirement. In 2017, the rope sheaves were dismantled for refurbishment. In 2021, the entire shaft frame itself was scaffolded in order to renovate it as well. Now the cable sheaves are being reinstalled. This is a very complex undertaking (Figure 1).

The bottom two of the four sheaves are not making it easy for the fitters. They are lifted with a powerful crane to the top floor of the approximately 70 m high shaft frame. There they are then “re-attached” to a chain that is bolted to a correspondingly designed beam on the crane runway platform (the upper edge). The crane then enters this crane runway again. It picks up the rope sheave again and sets it down on the mounting points of the lower rope sheave platform. The same is done with the second rope sheave. The two upper sheaves are hoisted directly through the crane runway and placed on the upper rope sheave platform. For this, the height rescue team is also deployed in addition to the cranes.

Over the next few years, the two Lohberg shafts and the shaft in Hünxe will be prepared for pumping mine water. To do this, the shafts will be filled in and at the same time equipped with casing pipes through which the pumps will then be lowered into the depths: three casing pipes each on Lohberg 2 and under the already dismantled Lohberg 1 headframe, and four more in Hünxe. This ensures that sufficient pumping capacity is always available. The planned start of pumping is scheduled for 2032. Then, a total of around 33 M m³ of mine water will be discharged into the Rhine every year.

Stefan Roßbach, head of department at RAG-Grubenwasserhaltung: “Lohberg is an important mine water site for us. From here, all the mine water from the Emschermulde basin flows into the Rhine. Lohberg was an important mining location for a long time. It will continue to be important in the post-mining era. Here we can present the entire RAG portfolio: in addition to mine water management, e. g., the development of areas for new uses, including the generation of renewable energies.” (RAG/Si.)

After around 15 months of construction, the first section of the 7.4 km-long mine water channel has been driven. The breakthrough after 3.2 km marks an important milestone for the long-term water drainage in Ibbenbüren.

“Today is a special day for RAG. We have completed the first stage of the mine water channel. My thanks go in particular to the miners involved. Of course, this is not the first breakthrough we have experienced here today. But this one here at the Miriam tunnel is a milestone for RAG” emphasised RAG CEO Peter Schrimpf. “This is an immensely important project for us; we will never pump water here, which is an ecological innovation.”

The innovative character of the long-term water drainage at the Ibbenbüren site is part of the mine water concept of RAG Aktiengesell­schaft, Essen/Germany. In Ibbenbüren, the mine water will be able to be conducted into the mine water channel without pressure – i. e. without the use of energy. After the mine water has risen to 63 m ASL, no pumps will have to be operated, as in the Westfeld. This means a significant improvement in water quality and energy savings. “On a day like this, you feel proud. A breakthrough with this precision is an uplifting moment. We have been working on this project for over ten years, so the breakthrough at the Miriam tunnel is very special,” said Jürgen Kunz, head of the RAG Ibben­büren division.

The breakthrough was eagerly awaited: the tunnel boring machine, christened “Barbara”, reached the centre shaft of the mine water channel at a depth of 73 m, exactly on target. This impressive moment was honoured by Schrimpf, Jürgen Rupp, CFO of the RAG Stiftung, Essen, and Kunz. Also present were the godmother of the western section, Miriam März, Head of the Human Resources & Development Division of RAG, and the employees of the Ibbenbüren Division of RAG who were involved in the project, as well as the project partners of the ARGE Tunnelbau consortium and representatives of the Arnsberg district government (Figure 1).

“This is my eighth breakthrough to date. You’re always afraid that you won’t hit it. And then it works down to the millimetre. Tunnel construction is an absolute team sport, it only works together. We are very happy today,” said Rukan Mengü, Tunnel Construction Manager, Shift Engineer at Wayss & Freytag Ingenieurbau AG, Frankfurt/M. in Germany.

The Miriam tunnel that has now been driven will enable the mine water from the eastern and western fields of the Ibbenbüren mine to be fed into the new mine water treatment plant in Gravenhorst, which is currently under construction. The breakthrough of the east drive is planned for December 2024. The mine water currently rising in the eastern field is not expected to reach the surface until spring 2026 at the earliest. (RAG/Si.)

The Saarland Ministry of Economic Affairs, Innovation, Digital and Energy (MWIDE) and RAG Aktiengesellschaft, Essen/Germany, with its subsidiary RAG Montan Immobilien want to join forces to expand renewable energy in Saarland. Minister of Economic Affairs Jürgen Barke and RAG Board Member Michael Kalthoff signed a Letter of Intent (LOI) to this effect on 17th November 2023 (Figure 1).

In recent decades, Saarland has transformed itself from a coal and steel region to a multi-faceted industrial and service location with an international focus. In this context, the move away from fossil fuels and the expansion and strategic promotion of renewable energies are key steps towards making Saarland not only crisis-proof but also future-proof. The success of the energy transition and the green transformation of companies is therefore a key function for the Saarland as a business location.

RAG is contributing to the LOI by examining its own areas for the expansion of renewable energies. After covering its own requirements, around 25 ha are currently to be made available for electricity production for commercial enterprises in Saarland. RAG will seek to cooperate with Saarland companies in the development and realisation process. Space, area and operating data will be exchanged with the state, associated organisations and scientific institutes. Best-practice solutions for the future planning and construction of renewable energy plants are also to be developed and considerations on citizen participation orientated towards the common good are to be promoted.

The MWIDE provides technical and political support for these processes. On the one hand, the aim will be to focus on legal requirements in the planning and realisation of renewable energy projects at an early stage and to implement these quickly. On the other hand, questions and dialogue on ways to speed up procedures and measures are also part of this. Various event formats are to be organised and supported in order to jointly promote the implementation of renewable energy projects to the public.

Kalthoff is looking forward to working with the ministry: “The RAG Group has a significant portfolio of conversion sites in the Ruhr and Saar regions and we are happy to support the plans to expand renewable energy. RAG wants to make a sustainable contribution – to regions worth living in, which are also home to the company. This is also an important part of our corporate strategy. In future, we will also cover our energy requirements for the operation of our water storage and administrative sites with our own green electricity. Our aim is to be CO₂-neutral by 2030.”

Barke: “Due to our historical, industrial structure, we in Saarland are particularly affected by the green transformation. Saarland is also very densely populated and the competition for land is clearly noticeable. We Saarlanders are no strangers to change. We have learnt to see it as an opportunity. Against this backdrop, I am delighted that we have succeeded in initiating a cooperation that will accompany both the state and RAG into the future. The energy transition, with its many and varied requirements, is essential for Saarland – it is the prerequisite for our economic future and the preservation of the location. Joint models and projects between the state and companies like this are needed. I would therefore be delighted if our cooperation were to set a precedent.” (RAG/Si.)

After intensive preparations, Iqony Energies GmbH, Saarbrücken/Germany, a subsidiary of the energy company Iqony GmbH, Essen/Germany, has decided to modernise and convert its existing district heating generation plants and district heating network on the site of the former Camphausen mine into an innovative and climate-neutral heat generation system (Figure 1). Waste heat from mine water from RAG Aktiengesellschaft, Essen/Germany, will be tapped as a new heat source and made available for the district heating supply to the town of Sulzbach. This will avoid annual CO₂ emissions of more than 6,000 t in the future.

The project had already received funding approval in December 2020 as part of a tender for “Innovative CHP energy systems” (iKWK) from the Federal Network Agency. Combined heat and power (CHP) plants generate electricity and heat at the same time and are therefore particularly efficient and resource-saving. However, extensive preliminary planning, many technical challenges and regulatory decisions in Berlin meant that the project could not yet be realised. Now, however, all the requirements have been met and realisation can begin.

In technical terms, the project consists of three coordinated components: a conventional CHP plant, the renewable heat source in the form of mine water and a heat pump that utilises the residual heat of around 36 °C contained in the mine water for the district heating supply.

“We are delighted to be able to help make a climate-neutral contribution to the heat supply with the mine water that we provide to Iqony. This mine water has a temperature that can definitely be used to generate heat,” says Michael Drobniewski, RAG Regional Representative for Saarland. Appropriate feasibility studies are therefore being carried out at all mine water drainage sites.

“Pumping the mine water naturally makes it much easier to tap into this ­unusual source of heat,” explains Dietmar Bies, who is responsible for the project on behalf of Iqony. The heat obtained in this way ensures a corresponding reduction in the use of conventional energy sources, meaning that the Camphausen CHP plant saves around 6,300 t of CO₂ emissions every year.

Because the third part of the plant, the conventional CHP plant, is also fuelled by an energy source classified as climate-neutral, the plant as a whole is already completely emission-free.

Anke Langner, CEO of Iqony Energies: “We use mine gas as fuel in the conventional CHP plant, which has a high methane content. When released into the atmosphere unburnt, methane is more than twenty times more harmful to the climate than CO₂. Accordingly, politicians have only recently confirmed the ice classification of mine gas as a climate-neutral fuel, which is why the use of mine gas as a fuel is also a sensible measure in the interests of the climate.”

What’s more, there will still be sufficient fuel available in the coming years. However, the legal categorisation of mine gas as an energy source was in limbo in the political debate for a long time. As a result, the realisation of the project in Camphausen also took longer than originally planned.

For the users of district heating in the municipalities of Camphausen and Sulzbach, including a hospital and industrial and commercial enterprises, this in turn means that the district heating supplied in future from the plant on the former colliery site is already green, i. e., climate-neutral.

It is not only against this background that Stadtwerke Sulzbach, as the local district heating supplier, and Iqony Energies have decided to continue their proven and successful collaboration and extend the corresponding cooperation agreement by 20 years. “We are delighted that we are continuing our cooperation and at the same time opening a new, climate-neutral chapter for the local heat supply with the conversion of the plant in Camphausen, which is now beginning,” says Langner. And Iqony has another piece of good news to report to the citizens of the two municipalities: “From a technical point of view, our plant still has potential to increase the generation of green heat. This means that nothing stands in the way of a possible expansion of a truly climate-neutral district heating supply on the generation side,” says Langner.

Construction work began in October 2023 and will take around 14 months. The plant is expected to be commissioned at the end of 2024. During the conversion phase, the supply of heat to the communities will be ensured at all times by means of mobile heating centres. (Iqony/RAG /Si.)

Tisa – this will be the future name of the tunnel boring machine that will drive the mine water channel from the central shaft to Oeynhausen’s shaft 1. The name was given to the Dorsten artist Tisa von der Schulenburg, who was closely associated with the hard coal mining industry. She not only thematised mining artistically, but also distinguished herself through a high degree of solidarity with the miners.

During a festive ceremony on 4th August 2023, the second tunnel boring machine for the construction of the mine water channel of the former Ibbenbüren mine of RAG Aktiengesellschaft, Essen/Germany, was symbolically christened by Pastor Andreas Finke and Pastor Paul Konnadur at the central shaft of the mine water channel (Figure 1). It is the second tunnel boring machine to be used for the construction of the mine water channel. It will drive a length of 3,867 m in the east section. In future, the mine water from the Ibbenbüren mine will be fed via the mine water channel to the new mine water treatment plant currently under construction in Gravenhorst.

Peter Schrimpf, Chairman of the RAG Board of Management: “The excavation of the mine water channel in Ibbenbüren is a very special project for us in many respects. It is, so to speak, the last excavation in the German hard coal mining industry. It is also an outstanding project in terms of investment volume. And it is a prime example of sustainability and the environmentally friendly handling of mine water. I wish us all continued success with the project. Above all, I wish everyone involved on the construction site good health. Occupational safety and the integrity of our employees and partners is and remains an essential element of our corporate culture.”

The channel is scheduled to be commissioned in 2025. (RAG /Si.)