My visit to Swiss salt works proved to be helpful in many
ways. Not just in terms of seeing the process of salt production, but
especially in rising further questions, which will influence and enhance the
direction of my project. I was surprised by a high rate of process automatization
which results in human power being replaced by computers. In the smallest Swiss
salt works, there are only 32 people working, while 3 would be enough to run
the production during one shift.
Salt production in Switzerland covers the whole demand of the country and part of salt is also exported to Italy and Germany. Salt in Switzerland is produced at three different locations, together employing 200 people. In the Alpine region, in Saline de Bex, the mountain salt is excavated in the form of the precious salt crystals, while in two salt works located close to Basel, in Schweizerhalle and Riburg, salt is evaporated from brine. Natural brine is also transported to local thermal baths and swimming pools and used for medical purposes.
Salt works in Riburg
Salt works in Riburg, which is slightly smaller than the one
in Schweizerhalle produces salt used for industrial purposes and de-icing of
the roads. Natural brine is transported from the leaching field through
underground pipes and stored in big cisterns.
Brine is processed in a 28 m high evaporator and
consequently dried in a centrifuge into a required dryness (its use depending).
Dry salt is then automatically transported with the movable belts either directly to the halls for loose salt or into a final production halls.
The whole evaporation process is highly automatic and only one person is needed for its supervision.
In the final production hall, salt is packed into 25 kg
bags which are then stored in warehouses.
The loose salt is stored in 2 long wooden halls with the dimensions of 65x38x18m.
Due to a high demand of de-icing salt, 2 domed halls were built recently. Saldome 1, with the diameter of 93m and the height of 31m and Saldome 2, with the diameter of 120m and the height of 32.5m. The two halls can store together 180 000t of salt and it takes 80 days to completely fill up each of them.
Saldome 2 is constructed of 1700m3 locally sourced timber and became Europe’s largest timber domed structure. Wood is a great material used for salt storage. While metal tends to have an aggressive reaction and corrode, wood lasts and doesn't have to be replaced for a long time.
Finally, the loose salt or salt bags are loaded and transported either by rail or LKWs.
Clear orientation and spatial organisation are highly needed for an easy transport. Historic wooden drilling towers are part of the areal and highlight the technology progress. Although they are not used any more, the drilling mechanism is still functioning. I even got the chance to try natural brine - yes, was truly salty.
I was lucky enough to have a great guide, who showed me also the rooms not otherwise accessible to the public (computer room and laboratory). He was interested in listening to the story of Slovak salt industry and apart from borrowing me suitable shoes, I even got a present – more than 20 salt shakers filled with pure Swiss salt!!
Salt works in Schweizerhalle
Unlike the salt works in Riburg, the salt works in Schweizerhalle fulfils all food-laws and so produces table salt, wellness salt and other types of salt. It acts as the main headquarter of Schweizer Salinen and includes laboratories, offices and a training centre. The salt works became a starting point for erecting neighbouring chemical plant, where salt (NaCl) is an inevitable component.