Saltworks

Thes saltworks is where the brine is boiled and concentrated in flat open vessels (pans). Two brick chimneys tower over the facility. This is where the final stage of evaporation and crystallisation by boiling the concentrated brine takes place. First, the liquid is transported from the graduation tower via a pipeline to the wooden reservoirs located on the premises of the Zakłady Produkcji Zdrojowej production plant. Once it has settled, it is transferred from to a heater made of steel sheets, where it reaches a temperature of about 45˚C thanks to the heat flowing from the pan into the chimney. The salt solution is then poured into a pan, where it is heated to a temperature of about 100˚C. The solution boils and a layer of scum forms on the surface, which has to be removed. After skimming, the temperature of the brine rises, the solution becomes oversaturated, and excess salt precipitates out in the form of crystals that resemble upside-down pyramids. The salt is then scooped from the bottom, stacked in heaps on a wooden drier with a built-in chimney that extends above the roof of the building. The salt scooped by the salt workers has a moisture content of about 30%, so excess water must be removed. After the initial evaporation, it is transported by wagons to a warehouse and dried. Simple tools are used for production: hoes and shovels, and everything is done manually. An average of about 80 m³ of brine is used per 72-hour cycle, and an average of 240 kg of salt is obtained from one 1 m³. The decoction yields 40% salt and 60% sludge. One cycle yields about 7,000 kg of salt, 10,512 kg of sludge and about 7 m³ of end lye.

Depending on the duration of evaporation, coarse or fine-grained salt can be obtained, which is then packaged. This is Ciechocinek’s boiled salt. Pan boiling produces the best kind of edible salt. During the boiling process, sludge and medicinal lye are also extracted that can later be used for therapeutic treatments.

The saltworks were set up close to the Vistula River for ease of access to water transport. The commissioning of the salt factory in the 19th century was hindered by the outbreak of the November Uprising, after which production started on 21 October 1832. There used to be several pan buildings. At the end of the 19th century, a separate railway siding was extended from the Ciechocinek railway station to the saltworks. A fragment of the track was left as a souvenir at the Plac Gdański square. Today, much less salt is produced in Ciechocinek.

It is Poland's oldest industrial plant still in operation and Europe's largest active factory with pre-industrial technology. The graduation and spring complex is unique at the global scale.

For several years now, the unused part of the Konstanty Leon Wolicki Salt Factory has housed the Saltworks and Spa Treatment Museum, which contains many exhibits relating to salt production and spa activities of Ciechocinek. A major attraction is the old baths and the antiquated devices for therapeutic gymnastics from the early 20th century. Temporary exhibitions are held in the disused heater. Various events are held in the saltworks, including the Salt Festival organised by the Society of Friends of Ciechocinek in cooperation with Uzdrowisko Ciechocinek S.A.

By a decree of the President of Poland dated November 22, 2017, the complex of graduation towers and the salt production plant, together with the graduation and spa parks in Ciechocinek, was entered on the list of Historic Monuments, i.e. monuments of particular significance for the culture of our country.