A fiery challenge: Repairing coke ovens at high temperatures

Imagine trying to fix your oven while it’s still hot enough to bake a pizza. Now multiply that heat by about 10, and you’ll get an idea of what our teams face when performing hot repairs on coke ovens in Brazil. This challenging and crucial work keeps steel production flowing and extends the life of vital industrial infrastructure.

The role of coke plants has shifted significantly in past years. In Europe, many plants have reduced output or shut down due to industry consolidation, stricter environmental regulations, and improved production efficiency, leaving the steel sector increasingly reliant on imports. In contrast, Brazil’s coke plants are vital for supporting the country’s large steel industry, which relies heavily on a steady supply of coke for production.

A well-maintained coke oven battery can last 35 to 50 years, but regular maintenance is essential to achieve this longevity, improve energy efficiency and reduce environmental impact. Maintenance must begin as soon as the battery is commissioned. After a period of operation, specific repairs to the refractory, steelwork and machinery are required to meet environmental regulations and improve performance. Hot repair is a specialised maintenance technique used in coke plants to repair problems without completely shutting down and cooling the ovens. This process has several key benefits:

• Minimises production downtime
• Reduces thermal stress on the ovens
• Saves energy by avoiding full cool-down and reheat cycles

Common issues addressed by hot repairs include cracks in refractory brickwork, damaged kiln doors and frames, problems with heating flues and regenerators, issues with bracing systems and contamination.

Our local expertise in Brazil

Our teams of RIP Serviços Industriais in Brazil have been at the forefront of hot repair technology for the past 22 years, working on some of the largest coke plants in the country. We now have over 1,500 employees actively involved in the repair and maintenance of coke plants – we even have our own training school. Lucas Wruck, Branch Manager in Espírito Santo, shares the importance of this work: “What I love most about my job are the daily challenges that make each step unique. The craftsmanship involved is something no machine can replicate, and it’s this hands-on precision that makes all the difference. I also love working with people, overcoming challenges together, and training new workers on a regular basis. Every hour counts, so the planning has to be spot on. This dynamic makes my job really exciting.”

The colleagues involved in hot repair, especially the bricklayers, show incredible dedication to their craft. It’s not just mechanical work – it’s an art form. Working in extreme conditions, these skilled craftsmen bring a high level of expertise to each repair, extending the life of the coke ovens while ensuring safety is paramount. As Lucas explains, the complexity of hot repairs requires a precise methodology as the surrounding ovens remain operational throughout the process, much like “changing a tire while the car is still running”.

Lucas recalls one of his most significant projects: “Without a doubt, the most special and challenging project was my first one at CSN, where I had to quickly learn the work methodology. I gained a lot of knowledge from experienced colleagues. But my biggest project is the one I am currently working on at ArcelorMittal Tubarão in Espirito Santo. This project stands out for its speed and the environmental benefits it has brought to the local community, something I am very proud of as a resident of this state.”

Health and Safety at the core

Due to the extreme working conditions and operational hazards, special safety measures are essential for hot repairs in coke plants. The challenges of working in an environment where the surrounding walls are at 950°C, combined with the pressures of customer operations and rotating workforces, add layers of complexity to any project. This physically demanding work requires not only precise coordination of people and equipment, but also a strong safety culture to prevent damage and protect workers. Continuous temperature monitoring, the use of heat-resistant materials and advanced personal protective equipment – such as cooling systems, heat-resistant clothing and gas masks – are critical.

Structural integrity is maintained through meticulous planning of support systems and controlled demolition procedures. By continually improving safety protocols and listening to the needs of our employees, we ensure high performance under challenging conditions. This comprehensive safety approach, combined with the expertise and dedication of our teams, allows us to successfully undertake these demanding hot repair projects.

Adapting to a changing industry

Looking ahead, Lucas emphasises the importance of maintenance work in sustaining operations for decades to come: “Especially here in Brazil, where relatively new coke oven batteries will remain in use for many years, maintenance will be essential as long as these plants operate. Hot repairs will evolve with technological advances, particularly in safety equipment, while sustainability and stricter environmental standards will drive further adaptation in the maintenance sector.”

Environmental challenges will also be a major focus for our customers in the future. Lucas explains: “Our clients will face growing environmental pressures in the coming years, which will require more frequent maintenance and repairs to meet regulatory standards. On top of that, economic pressures, particularly competition from China, will create uncertainty and push the industry to stay agile and efficient.”

Mastering the heat, one repair at a time

So, the next time you’re baking a pizza at home, take a moment to appreciate that while your oven may just need a quick clean, Brazil’s coke ovens rely on skilled teams working in extreme heat to keep steel production moving forward. The challenges may be fiery, but the dedication and ingenuity behind these hot repairs ensure that the essential infrastructure of steel production continues to run smoothly. Now, that’s a job that goes far beyond a quick fix!