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Messaggeria in lingua italianaNew book: "Le Cetine di Cotorniano. Miniera e Minerali"

14th Sep 2015 10:02 UTCMarco E. Ciriotti Manager

Referenza:

▪ Menchetti, S. & Batoni, M. (Editors), Batacchi, C., Borselli, G., Brogi, A., Ceccantini, L., Fassina, B., Marchesini, M., Rossellini, A., Ruggieri, G. (2015): Le Cetine di Cotorniano. Miniera e Minerali. AMI, Ed., Cremona, 353 pp.

In lingua italiana e inglese.

Il prezzo di vendita:

- soci AMI € 38 (trentotto)

- non soci € 45 (quarantacinque)

Chi è interessato può ordinarlo scrivendo a: m.ciriotti@tin.it

Per le spedizioni via posta all'estero il costo aggiuntivo può variare secondo la destinazione, per le destinazioni in Italia il maggior costo è dell'ordine di 10 €.

Il pagamento può essere effettuato come segue:

c/c postale n. 93325421

Si ricorda che nella causale occorre precisare:

a) nome cognome, recapito completo e indirizzo e-mail di chi effettua il versamento;

b) l'indicazione di quanto pagato (per esempio: "libro Cetine"").

Per coloro che intendono effettuare il pagamento mediante il sistema bancario le coordinate del conto AMI presso le Poste Italiane sono le seguenti:

IBAN: IT-24-E-07601-01000-000093325421

Codice BIC/Swift: BPPIITRRXXX

CIN: E

ABI: 07601

CAB: 01000

C/C: 000093325421

Qui di seguito un estratto dalla parte storica:

"History of mining at “Le Cetine”

Mining operations for antimony ore extraction at Le Cetine covers a time span of 72 years, from 1878 to 1949; during this time interval the mine produced 61,215 tons of antimony ore.

Part of the activity was carried out as surface mining and part as underground works.

Due to the importance of antimony in the weapons production, and the fact that its deposits are not widespread, the rise and decline of the mine is intimately linked to the historical, economical and social evolution of Italy.

The history of the mine is described highlighting some original text retrieved from the annual reports of the Royal Mining Authority (at that time Italy was still a Kingdom).

Data reported by the Mining Authority (“Corpo delle Miniere”) are the backbone of our story, as they are a remarkably complete and detailed source of information about the mine.

The original quotations in the Italian version are “copied and pasted” in Italic, keeping them as much as possible identical to the archive sources. Today some of the statements might sometimes look a little overstated, but are part of the cultural climate of the past.

The economic history of the mine can be divided into four periods:

1) First period – From early times (1860?) to 1898. Significant works were started around 1878 and were continued with ups and downs, until the end of the 19th Century. Only a few high grade veins were mined, obtaining modest incomes.

Antimony minerals were known since at least 1862, when G. Campani mentioned “antimony sulphide” in the Cetine di Cotorniano area.

The area belonged to countess A. Piccolomini-Clementini that until the mid-1980s also owned the mine itself. The first excavations were aimed to provide antimony for the weapons industry. One of the best years was 1883, when 222 tons of processed ore were produced.

Around 1884-1885 the Company “Società Anonima Miniere e Fonderie di Antimonio di Genova” bought the mine and the smelter in Ponte del Rosaio. The director of the Company was G.B. Traverso, a well known mining engineer and mineral collector. The works were limited to open pits and trenches and the production was relatively small in a range of around 100-300 tons per year, except for 1883 when it peaked to 1690 tons.

The first tunnels were dug in 1886, bringing interesting new data to outline the deposit, but without increasing significantly the production rate.

In spite of all those efforts, it was difficult to maintain the production rate as high as hoped, mainly due to the limited extent of the ore bodies and to the technical limitations of the smelting facilities, capable of operating effectively on ore with not less that 30-50% of stibnite. Huge amounts of ore with 15-20% of stibnite were set aside, waiting to be treated later, and the lesser quality ones were dumped.

The first working smelter was built in 1899, but the enrichment plants started to work at an earlier stage. The process can be summarized as follows:

a) Tout venant crushing and manual highgrading of the best material, to be sent to the smelter and lower quality ore to be further highgraded.

b) Manual enrichment of the lower quality ore.

c) Roasting of the material selected in steps a) and b) to produce the sulphide rich compound to be processed in the main smelter.

The relatively high deposit heterogeneity and the presence of huge amounts of native sulfur in the hosting rock made the operations quite challenging as the blasts often caused the sulfur to catch fire, increasing the risk for the miners and leading to loss of time. The lack of water also prevented the development of a proper washing and sifting plant.

Working conditions were really hard, as in all mines in Europe or elsewhere at that time, and children were employed to do low paid work.

2) Second period - 1899 to 1908; This was the best period of the Le Cetine deposit. During the first 6 or 7 years the mine produced remarkable income to the mine owners, boosted by high grade ore production and high antimony price. The high quality, arsenic-free antimony oxides were used not just for weapons production, but also for other non military uses such as the production of paints. New technological solutions were tested, enabling the operations to profitably mine mid-grade ore.

A new smelter complex, capable of processing the low grade ores, was built within the mining site. This represented a significant improvement in the mining activity, as it allowed to mine previously discarded or dumped low concentration ore. The number of workers peaked in that period to 300. A large open pit was excavated, and the different levels were given the names of “Bice, Borghese, Henfrey, Ribasso Superiore”. Part of the work was carried on by digging tunnels to follow the richest deep ore accumulations. A peak in the activity was recorded in 1906, when the price of antimony rocketed after the start of the war between Russia and Japan (1904-1905).

Important investments were budgeted to follow up the favourable market conditions, including the exploration of other antimony leads in Tuscany. Then, as rapidly as they grew, the raw material prices decreased abruptly, following the 1907 financial crisis.

The fast depletion of the best ore sections combined with the antimony price fall, caused a fast decline of the production, and to the closure of the mine in 1909.

3) Third period - 1915 to 1918; after a 6 year break, during World War I the mine had to be re-opened due to the need of raw materials. Initially stored stock were processed in the refurbished plants, and at a later stage the underground mining was resumed. The Le Cetine plant also worked ore shipped from Sardinia.

Mid-grade ores were mined with the operations driven mainly by the needs of the Italian market.

The mine initially had about 70 workers and mainly concentrated on relatively poor ore. In 1916 the production was 1494 tons, and the following year it peaked to 2100. The operations involved the Pozzo Benedetti, livello Henfrey, gallerie Centurini e Fanna, ribasso Falegnami, galleria Roghiccioni, Uliveto sections.

In 1918 the ownership of the mine passed to the Società Anonima Miniere e Fonderie di Antimonio, that had acted as mine operator since 1884-85 but, as soon as the First World War ended, the mine was closed again (1919).

4) Fourth period - 1936 to 1948; after an 18 year break, the mine was opened again because of the need of raw materials related to international sanctions and the start of World War II. This occurred in spite of the discouraging outcomes of the technical report, that clearly stated that the best ores were all mined out and that the processing plants were in an extremely poor state.

From 1937 to 1944 the production rates were generally low and the associated cost quite high. A 1937 report showed that due to the unavailability of a local plant, the ore from Le Cetine was shipped to Sardinia for processing.

The ore was generally characterized by a 9-10% Sb sulfide content. In 1938 the production reached again the respectable value of 1726 tons.

Seven new section were explored, including Garibaldi, Brucione, Scrosci and Caminetto.

In 1939-40 a new small smelter was built and started to process the local ore.

With the beginning of World War II, it became mandatory to ensure antimony production. The exploration and exploitation continued in Garibaldi, Brucione, Discenderia, Bice and Henfrey sections.

From 1941 to 1943 the production reached 2326, 2230 and 1942 tons respectively.

The 1941 production was remarkably high, especially considering that the mine was temporarily closed due to a major fire, that prevented access to the underground levels for days.

The concession was formally re-established in 1942. The mining sections included Fanna, Henfrey and Bice, Garibaldi, Scrosci, Brucioni and “regione Gesso”.

After September 8th, 1943, the German army occupied part of Italy, and the Le Cetine mine worked antimony ore for the Nazi-Fascist alliance until the arrival of the war front moving from South to North. The Allied army and the Anti-fascist Italian forces arrived in the area and found that the German forces had blasted the processing plant.

With the end of the war, the operations were suspended until the end of 1946. A 1948 report shows that in 1946-1947 limited activity was carried out, employing just 5 workers.

The poor conditions of the facilities, the unfavourable market prices and the lack of accessible good quality ore made further operation unfeasible. The mining concession expired in 1949, when the mine was closed again for the last time.

The exploration of epithermal gold (1985 – 1990) and the site maintenance

Small scale gold mining exploration took place in the 1980s. In 1985 the mining section of the Ministry of Industry (Direzione Generale delle Miniere) sponsored geological studies targeted at identifying possible epithermal gold ore deposits. The target for these studies were very large accumulations of low grade gold-bearing rocks with a metal content as little as several ppm (parts per million).

In Tuscany some interesting locations were identified, including the area around Le Cetine. In 1990 about 50 samples showed a concentration above 1 ppm: a potential too low to allow further initiatives."

The local Council (Comune di Chiusdino) later 2000 started works aimed to promote creation of a Park (“Parco Minerario delle Cetine”). Safety measures were implemented, such as removal of unstable rocks, installation of gates and railings and opening of walkways. The lack of financial resources seems to have prevented the completion of the project."

19th Sep 2015 10:43 UTCMarco E. Ciriotti Manager

Il libro sarà presentato e sarà distribuito in occasione di EuroMineralExpo di Torino (2-3-4 ottobre 2015).

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