Our concept of the circular economy entails more than recycling end-of-life goods or the recovery of waste materials. We also concentrate on the “inner loops” in the value chain, including better utilization rates for products by reusing, repairing, refurbishing, or remanufacturing them. These measures all contribute to extending the lifetime and/or utilization of plants and equipment, thereby delaying the demand for new products. With more than 2,000 specialists for electrical and automation systems, digitalization, and technical service, we can effectively cover this part of the circular economy. Our experts pool their expertise not only to supply new equipment to customers but also to deliver tangible benefits during plant operation.
Repair: Back to original state
Reprocessing used equipment and components and restoring them to their original state is part of what we do every day. This task is handled by more than 50 SMS group workshops all around the world. A typical area is the repair of molds, oscillators, and segments for continuous casters. For hot rolling mills, our repair and service portfolio includes the overhaul of work and backup roll chocks, drive spindles, gearboxes, downcoiler mandrels and reels, and HGC (hydraulic gap control) cylinders.
In bar and wire rod mills, the rolling cassettes in a PSM® (precision sizing mill) are subjected to enormous mechanical and thermal stresses during the rolling process. To ensure that the cassette can withstand all these loads, we offer regular maintenance and repair for the installed components. SMS also offers a circular system in which customers bring worn cassettes to a one of our workshops and in return take a repaired cassette with them. This outsource concept ensures that all components are always adjusted and installed according to OEM specifications.
Coatings are another field of expertise of our service workshops. By applying a wear-resistant coating to molds, rolls, shafts, or chocks, we can increase the campaign length by up to 600%, while the product quality remains constant over a longer period of time. Broken or impaired equipment and components can often be repaired by coating them.
Repairing equipment is a reliable way of increasing the utilization rate of components. However, how can a customer work out the best interval for repairs—not too early, but not too late? Our Genius CM® Condition Monitoring is a predictive tool that is based on equipment and process data. It can derive maintenance tasks that need to be carried out before the plant’s productivity is negatively affected. Most importantly, predictive maintenance helps to avoid damage to the equipment and thus eliminates the need to fully replace a component.
Reuse: More than one lifecycle
The concept of reusing equipment after its first lifecycle can be applied to components as well as to entire plants. A good example of the reuse of components is the circular system for molds in continuous casters for long products. Our clients benefit from a circular process that includes delivering new mold tubes, picking up used tubes, and refurbishing used copper tubes – all against the background that SMS group “owns the copper.”
It all starts with a one-time contract that defines the basic commercial conditions. This is followed by manufacturing in our Concast workshop in Switzerland. At the same time, a stock is established to ensure that any requested tubes can always be delivered on time. Once the tubes are used, SMS group picks them up, checks them, and decides whether they can be refurbished or if they need to be remelted. In both scenarios, the copper is fed back into the circular process.
This procedure helps the environment by minimizing transport, reusing the copper, and achieving overall resource savings. Our customers benefit from easy and fast processes from one source that come with attractive pricing. Only the conversion costs are invoiced, there is generally less cash out, and the risk of copper price and exchange fluctuations is eliminated. Furthermore, a delivery contract can be concluded for faster supplies, including emergency stock.
The example from Handan Iron & Steel shows that metallurgical plants are living systems, where reuse and redesign are often closely connected. The heavy plate mill at Handan was built in 2006 by a local supplier. Just seven years later, Handan commissioned us to redesign the mill. Among other things, the order included upgrading the finishing stand with more powerful components, such as new hydraulic adjustment and work roll bending systems, to increase product quality. The existing hot plate leveler was moved in front of the plate cooling system and reused as a pre-leveler. After another seven years of successful operation, Handan decided to relocate the plant from the center of the city to a suburb due to environmental reasons. It was our job to bring the level 1 and level 2 X-Pact® automation systems up to the latest state-of-the-art and to integrate an additional roughing mill stand into our systems. The general commissioning was successfully completed in a record time of six weeks until the first plate was produced. The total delivery time was only 10 months, something that had never been achieved before, especially against the backdrop of global supply chain difficulties.
Redesign: Improve cometitiveness
For all our plants, we offer a multitude of solutions to substantially improve our customers’ competitiveness at moderate investment costs. These technologies, components, automation solutions, or services are specially designed to retrofit existing plants with low or medium investment. Each of these “performance modules” helps customers improve the performance of their plants in one or several areas and hence achieve a competitive edge in a tough market environment. This means the modules will not only increase plant productivity and product quality but also reduce operating costs and allow new, high-margin products to be introduced. An example for copper recycling plants is the “tuning package” for tilting refining furnaces. With only minor equipment and automation modifications, plant capacity can be increased by over 20%.
Extensive modernizations are often very complex and require a great deal of experience. A successful revamp is not only about implementing new technology in an existing infrastructure but also keeping downtimes to a minimum. That’s why modernizations start with a thorough analysis of the as-is situation and the goals of the project. Shutdowns are the most critical part of revamp projects. To avoid unpleasant surprises, we leave nothing to chance. Preparatory work is done during routine maintenance downtimes and regular shutdowns. Pre-assembly of equipment and testing of the automation also minimize risks and guarantee that production can start as soon as possible.
A recent example of a successful revamp was the capacity increase of the pickling line/tandem cold mill at ArcelorMittal Vega in Brazil. By adding another mill stand, the capacity of the 20-year-old PL-TCM was increased by 640,000 to 2.15 million t/year. The modernization enabled ArcelorMittal Vega to extend its product mix and offer ultra-high-strength steel strip for the automotive industry.
To meet these targets, the existing four-stand cold rolling mill was expanded to include a fifth stand on the mill’s entry side. Before the shutdown, the new mill stand was assembled and pre-commissioned in an assembly pit next to the mill, with regular operations remaining uninterrupted. In parallel, the foundation for the new mill stand was prepared underneath the entry of the tandem mill. At the beginning of the shutdown, the mill’s entry equipment was disassembled, and the ceiling of the cellar was cut out to provide access to the new foundation. Lastly, the new “mill stand no. 0” with a total weight of 360 tons was shifted into its final position.
