Why use new materials when, with little effort, used ones can be recycled? For a long time now, the utilisation of metals that have already been used has not been a new aspect; especially the melting of aluminium is common practice.
The industry also needs a lot of water, which in the past was not often reused. Thyssenkrupp now recycles 97 per cent of the used water so that it can be reused in production. Contamination is removed, if necessary, between up to 40 uses. In this way, the company can not only conserve local waters such as the Rhine but at the same time save costs.
Resulting by-products such as gases or slag can be specifically separated and discharged in the process in order to enable further processing. Blast furnace slag is processed into granulated slag, which can be used in the production of concrete. In theory, CO2 can also be completely separated so that it does not escape into the environment. "Carbon Capture and Storage” (CCS) stores carbon dioxide in many different ways. Thus, in the future, empty natural gas or oil reservoirs underground will serve as pressure chambers for CO2. This would allow climate-friendly - albeit not climate-neutral - production. Some electricity companies are already separating the gas in order to store it for testing purposes.
For example, Thyssenkrupp relies on "Carbon2Chem": CO2 is largely converted into ammonia in this process, which in turn can be used sensibly in other processes.