In the "Tin plate" project, the partners developed a resource-conserving efficiency technology for the closed-loop recycling of metals and rinse water in tin plate production.
High quality steel products are often refined by coating them with tin, zinc, chrome, nickel or copper. The partners developed a method to recover and reuse tin on the one hand, and minimise the use of fresh water on the other.
The recovery of tin and the closed-loop recycling of process water are possible using a membrane separation process. The project partners have replaced the conventional evaporation technology with an innovative operating concept featuring durable membranes which recycles all the other electrolyte components as well.
In addition, a general efficiency concept was developed to improve the productivity in coating lines. Once the project is completed, the membrane separation process can be used directly in tinning lines, and the general efficiency concept ensures resource-efficient operation in diverse coating lines.
Using the developed technology can reduce both the energy required for coating and the CO2 formed. Furthermore, it is possible to conserve tin, electrolytes and fresh water due to the closed-loop recycling of tin and rinse water in the multi-stage tinning process: In comparison to the evaporation technology, up to 7.5 tonnes of tin can be saved per year and plant and water consumption can be reduced by about 12,500 cubic metres per year and plant.
The method could also be applied in steel and metal-working and the electroplating industry. Furthermore, it could be transferred to coating lines using zinc, nickel, copper, chrome and other precious metals in the medium to long term.