Grupa Kety S A : Suggestion of the first half of 2023 under the ‘Green Group’ programme – a perfect example how to reduce carbon footprint and apply ‘circular economy’ in practice

The awarded project consisted in using sodium hydroxide waste from press moulds etching in another process at KĘTY S.A., i.e. anodised products manufacturing.

At the moulds etching line, moulds are cleaned of aluminium remains by way of bathing in NaOH solution. Moulds are steel tools which give the aluminium profiles their shape in the extrusion process. Post the extrusion process, a mould may be contaminated with aluminium, which - if it may not be removed mechanically - is eliminated in the process of chemical treatment, namely bathing the moulds in 30% solution of sodium hydroxide Owing to the requirements for cleanliness and quality of the etched moulds surfaces, the hydroxide needs to be replaced as soon as sodium aluminate low-concentration solution is formed.

Further, in the process of treating profiles before andising, products must be etched in NaOH, in order to remove a film of oxides formed on their surface during heat processing and extrusion.

It appeared that at proper anodising optimisation, the waste hydroxide from etching the moulds is a full-quality substitute for pure sodium hydroxide purchased at high prices. Therefore, implementation of the suggestion enabled elimination of the cost of purchase of NaOH from third parties and considerably reduce the costs of lye utilisation at the moulds etching plant. The financial effect is not the only benefit. Thanks to the project, external transport related to waste hand-over will be eliminated, as well as the waste processing, which results in a significant emission to air and water, and consumption of energy and other resources Eventually, emission to the environment will be eliminated, specifically that of greenhouse gases causing unfavourable climate changes. Such use of recovered sodium hydroxide perfectly fits the Environmental and Climate Policies of Grupa KĘTY.

The suggestion will also eliminate energy-consuming production of pure sodium hydroxide, which will not have to be purchased from other sources. That perfectly fits the concept of circular economy, in which materials should circulated in economy as long as possible, and waste production should be limited to the highest possible extent.

The use of sodium hydroxide with a slight admixture of sodium aluminate is safe and reliable. The method of use and the risks related to that are identical as for the purchased sodium hydroxide, and the applied blockers fully eliminate the risk of an emergency situation.

The winning suggestion has been prepared by Maciej Zawadzki. In the implementation group he was assisted by Wojciech Tlałka and Mariusz Martyniak. Congratulations!