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chemical plant / Casteltermini / 1960 - 1991 / 2011 / MONTECATINI SALSI San Cataldo


This chemical plant was opened in 1960 by SALSI-Società Salifera Italiana – a subsidiary of Montecatini mining-chemical enterprise – with the aim to process the potash mineral (kainite) extracted at San Cataldo. The plant used a process studied and patented by Montecatini, which allowed to obtain 50-52% potassium sulphate (for industry and agriculture) from mineral kainite containing about 15% potash through three main steps: 1) transformation of kainite by treatment with middle liquor, giving crystalline schoenite and end liquor; 2) continuous leaching of the schoenite with hot water giving moist potassium sulphate and middle liuquior, which after cooling is re-used in the preceding operation; 3) drying and storage of potassium sulphate. Since the end liquor obtained in the first phase contained about 30% of potentially recoverable potassium, several efforts were directed towards the development of a recovery process. Tested first in the company's "Guido Donegani" research center in Novara, the innovative syngenite process was then implemented at Campofranco in 1965. In few words, by adding solid calcium sulphate to the end liquor a double calcium potassium sulphate (syngenite) was formed. The latter was then decomposed with hot water and reintroduced in the main process second phase.



As a consequence, the overall capacity of the plant was increased from the original 150000 t/y up to 210000 t/y. The two massive reinforced-concrete parabolic silos capable of 20000 t each one were thus enlarged and better connected to the railway line, to reach the chemical fertilizers factory at Porto Empedocle. Until the construction of the larger Pasquasia potash refinery by ISPEA in 1973, the Campofranco refinery was the only one of its kind in the whole country, being then a site of key-importance for the entire national agro-chemical industry. During the 1970s the concentration of Sicilian potash mining and transformation business in the hands of the regional mining authority (EMS) led to the disengagement of Montedison (succeeded to Montecatini in 1966) from the Campofranco chemical plant and related San Cataldo mine. In 1978 both the sites and the owning company SALSI were taken over by ISPEA. Differently from the mine, which was close to exhaustion, the Campofranco plant was assigned in 1981 to a newborn public-private company called Italkali-Società Italiana Sali Alcalini. Under the management of Italkali the Campofranco refinery was renovated and updated with a flotation plant for crude kainite mineral. However, the prospected positive future development for the Campofranco refinery was brutally interrupted in late 1990 by a conflict arisen between the Italkali management and EMS – which controlled 51% of Italkali –, having as object the Pasquasia mining-chemical plant. Finally, both the plants were closed in 1991.

















Adamo, S., Ramberti, L. (1979), "L'industria estrattiva del potassio in Italia", in L'industria mineraria, maggio-giugno 1979, pp. 161-170.

Cavalli, L., Maggiore, M. (1968), "Industrial and technical aspects of the recovery of potash by means of syngenite", in Fauser, G. (ed), Chemical Fertilizers: Proceedings of the XVII International Congress Chemistry Days. Pergamon, Oxford.

"Sviluppi produttivi della Montecatini", in La Chimica e l'Industria, vol. 43, n. 2, 1961, pp. 221-223.

Trincheri, G. (2001), Industrie chimiche in Italia dalle origini al 2000, Arvan, Mira.



Un mestiere per Tutuzzu (1961) | A short documentary movie by Montecatini Group showing its owned potash production centres in Sicily. The protagonist is a young shepherd, representing the poor economy of the region, who can take advandage of the new, modern potash industry to find a better job and then improve his condition. From 4:30 to 8:15 Campofranco chemical plant is shown.


La Settimana INCOM (11/5/1962) | Newsreel dedicated to potash mining industry in Sicily. From 03:37 to 05:55 Campofranco chemical plant is shown.