Metal pouring into sustainable trough
Metal pouring into sustainable trough

Pouring effort into sustainability

With climate change becoming an increasingly pressing issue, we’re always on the lookout for innovative ideas that enable us to become more sustainable as a business and create more environmentally friendly solutions for you. One such example is at our foundry in Lohr, where we’re helping the environment chip by chip – saving raw materials and reducing CO₂ emissions by an amount equivalent to that removed by 1.4 million trees.

Our foundry in Lohr, which makes hydraulic parts, has been climate neutral for some time now. That’s no small feat considering the energy-intensive production process that occurs at the foundry. But by purchasing green electricity and making the process more energy efficient – for instance by using waste heat, and switching the suction systems, sand mixers and batch coolers used in sand processing on and off as required – we’ve been able to achieve this important goal.

However, driven by the desire to make the foundry even more sustainable, Tamas Vagner (Head of Purchasing for the casting department) approached Totnan Bald (Technical Plant Manger at the foundry) at the beginning of 2020 with an idea: “Let’s recycle chips made up of the same raw material from our plants and use them as a raw material for new cast parts.”

Totnan Bald had already used chips from foundry production processes in previous jobs, so he was a supporter of the idea from the offset. “I believe it makes good sense to use chips. The new process is very important for our foundry, as it saves considerable amounts of pig iron and energy.”

Driving the idea forward

With this idea front of mind, André Klawiter (Group Purchasing Manager for the foundry) took charge of the project together with Dominic Reith (Melting Plant Manager) and Christian Reuter (the foundry’s Quality Manager).

Bosch Rexroth Lohr Foundry Team

Pictured in front of the chip store (from left to right): Dominic Reith, André Klawiter, Totnan Bald, Christian Reuter, André Kramer, Tamas Vagner.

Firstly, they looked at the availability of chips. These are obtained when we machine cast parts at our foundries in Lohr, Augsfeld, Horb, and also at one of our external suppliers. In the past, the chips were sold to external recycling companies, but now they’re reused by the foundry. They’re made up of the same metal that’s produced during the melting process.

One of the things that acts in our favor is that we use water-based cooling lubricants, rather than oil-based cooling lubricants, during machining. This means that no oil residue sticks to the chips, which could cause problems during the melting process. The chips are pre-dried in centrifuges and then transported to the foundry. “Unlike in other foundries, we’ve refined the process so the chips can be used as they are and don’t have to be pressed into briquettes first. This further reduces energy consumption”, stressed Totnan Bald.

Meeting quality standards

As with all the other materials we use, the chips supplied are tested at random and checked for composition and foreign substances by our Quality Assurance team. During the melting process, samples are taken for quality assurance purposes. Using mass spectrometers and thermal analysis, the chemical composition is determined, to make sure the quality of the cast product is up to standard.

Saving 14,000 tons of CO₂ emissions per year

By using these chips, the foundry can save several thousand tons of pig iron every year, helping to conserve natural resources. We have calculated that at least 14,000 tons of CO₂ emissions per year can be saved. 1.4 million trees would be needed to absorb the same quantity of CO₂ from the atmosphere.

Recycling metal chips isn’t just good for the environment. It also eases uncertainties when it comes to procurement. “The price of pig iron has risen sharply in recent years and there’s no end in sight”, emphasized André Klawiter. “Using chips means that we’re less vulnerable to future pricing and availability risks.” The foundry can also significantly reduce its consumption of expensive additives such as silicon alloys because the chips contain five times more silicon than pig iron.

For Totnan Bald, the recycling of chips at the foundry is a flagship project. “The switchover was a joint effort on the part of associates and managers at the foundry and the other plants involved. It shows the innovative and futuristic way of thinking at our foundry.”

Yinan Gu

Yinan Gu – Mover for sustainability

As well as being our Mover for sustainability, Yinan Gu worked as the Energy Manager for the foundry for more than two years, so she has a particular interest in this project: “I’m so pleased to know that this initiative has been implemented. To ensure process safety and to guarantee the required quality standards, plenty of experiments and tests have to be done, so it’s impressive that the team has got to this stage in this timeframe. This project demonstrates that to succeed, you not only need a good idea – you also need expertise, conviction and focus to achieve a stable, reliable and sustainable result.”

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