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Geology

Impressive mining activity in the area



For the record...

 

Cyprus' name has long been linked to copper (Cuprum). Vertical copper production on the island began 3000 BC. The ancient Cypriots were not only expert miners but superb metallurgists too. They had identified almost all the available copper deposits, extracting the best ones with underground and metallurgical methods, the basis of which is still used today, and they succeeded in producing high-clarity copper metal (copper ingots). It is a notable fact that the waste from the metallurgical processing, known as slag heaps, contained little copper. These slag heaps are often found close to copper mines and are now protected as ancient monuments.

 

In more recent times, the exploitation of copper started in the Skouriotissa area around 1921 and continued until 1974. For the extraction of the ore, both open-cast and underground methods were used. The main underground methods were driving successive horizontal floors or storeys or filling the void with sandfill or hydraulic sandfill using cemented rockfill containing waste from the enrichment plants. In open-cast mining, the main method was closed excavation with benches, due to the relief of the areas. At the same time as copper sulphide ores were being extracted, so were other sulphide ores, mainly iron pyrites.

 

For the most part, the mining method used was froth flotation of the copper ores (copper pyrites, bornite, covelline, chalcocite, cuprite), iron pyrites and other sulphides when they were contained in the ore. Enriched copper ores (copper concentrates) contained an average of 19% and were extractable. Since certain copper ores (malachite, azurite, chrysocolla and to some extent chalcocite and cuprite) are water soluble, the dissolved copper was precipitated with scrap iron to produce copper sediments with a concentration of 55-65%.

 

Finally, in certain mines and in smaller-scale mining excavations, gold and silver were also produced, in the form of inclusions or free grains of metal in the copper and iron pyrites flotation concentrates. The product could also be produced from the ores which were found at the upper surface of the mines (iron caps) and were mainly leached lava. Also, cyanide leaching was applied to certain forms of these ores of gold and silver followed by zinc dust precipitation and the production of gold and silver sediments.

 

 

Skouriotissa Mine

 

The mining area of Skouriotissa is where the Phoukasa, Phinika and Tria Vounarka deposits were discovered and they continue to be exploited to the present day.

 

The partial exploitation of the Phoukasa deposit began in antiquity, a fact that is backed up by the presence of ancient slag heaps (around 2,000,000 tons) and the ancient galleries that were discovered there in more recent times.

 

Its systematic exploitation began in 1921 and still goes on. From 1921 to 1974, mining was both underground and open-cast, and some 7,804,000 tons of ore was extracted, with an average concentration of 2.3% copper and 42% sulphur. Processing took place in an enrichment plant at Xeros, for the production of ingots of copper and iron pyrites and the precipitation of the dissolved copper with scrap iron for the production of copper sediments, while the end products were placed on a shiploader at Xeros for export.

During the period 1982-1993, some 608,000 tons of low quality ore with an average concentration of 0.8% copper were mined and processed using the flotation method with the a slightly acid solution and its precipitation with scrap iron for the production of copper sediments with a copper concentration of 70%.

 

Since 1996, however, a hydrometallurgical unit has operated in the area, producing copper cathodes that are 99.999% pure through the exploitation and processing of low quality copper and implementing innovative processing methods (dissolving the ore with the help of a light acid solution with an organic extractant – electrolysis). It is estimated that by 2007, 7,500,000 tons of ore with an average concentration of 0.7% copper had already been extracted.

 

 

Xyliatos Mine (Memi)

 

It operated from 1954-1971 and partially from 1987-1990. Open-cast mining was used to extract around 2,125,000 tons of iron pyrites, with an average concentration of 26% sulphur. Processing took place in the ore enrichment plant at Mitsero with the aim of producing sulphur ingots with the flotation method. The end product was exported from the shiploader at Karavostasi and after 1974 from Vasilikos. It is worth noting that towards the end of the 1980s, the end product supplied the sulphur oxide and fertiliser plant at Vasilikos.  

 

 

Alestos Mine

 

It operated from 1971-1972 and, through open-cast mining, some 661,000 tons of ore with an average concentration of 0.9% copper were extracted. Processing took place in the ore enrichment plant at Mitsero with the aim of producing copper ingots using the flotation method. The end product was exported, having been loaded onto ships at Karavostasi. During the 1980s the mine was the location of a small hydrometallurgical unit producing copper sediments with the use of a slightly acid solution and the precipitation of the dissolved copper with scrap iron.

 

 

Kokkinopezoula Mine (Mitsero)

 

It operated from 1953-1966 and, through open-pit mining, extracted around 5,486,000 tons of ore with an average concentration of 24% sulphur. Processing took place in the ore enrichment plant at Mitsero, producing sulphur ingots through flotation. They were exported by ship from Karavostasi.

 

 

Kokkinoyia Mine (Mitsero) 

 

It operated from 1973-1979 using underground methods and extracted some 481,000 tons of ore with an average concentration of 2% copper and 35% sulphur. It was brought to the surface via a gallery and a mineshaft while processing took place in the ore enrichment plant at Mitsero with the aim of producing copper and sulphur using the flotation method. The end product was exported by ship from Vasilikos.

 

On the site of mine today one can still see the mine cage equipment and part of the railway line on which the ore-carrying wagons ran. These installations will be part of a mining heritage museum to be established at Mitsero.

 

 

Agrokipia 1 Mine

 

It operated from 1952-1971 as an open-cast mine from which about 333,000 tons or ore with an average concentration of 1% copper and 38% sulphur were extracted. Processing took place in the ore enrichment plant at Mitsero with the aim of producing copper and sulphur using the flotation method, while the end product was exported by ship from Karavostasi.

 

 

Agrokipia 2 Mine

 

It operated from 1958-1964 using underground methods and extracted some 74,000 tons of ore with an average concentration of 4% copper and 40% sulphur.

 

 

Amiantos Mine

 

The main type of asbestos in Cyprus is chrysotile or white asbestos. Systematic exploitation dates back to 1904 and it continued until 1988 when pressure from the international market over the use of asbestos products brought an end to its operations.

 

The deposit that was exploited the most is in Troodos, north of the village Kato Amiantos in the Limassol district. It was extracted through open-cast mining, mainly open excavation with benches using heavy duty high capacity mechanical equipment for the excavation, loading and transportation of the ore. The annual extraction of ore often exceeded 5 million tons and the ratio of the excavated ore to the end product was about 150:1. The enrichment plant was very close to the mine and the method applied was that of crushing and classification of the ore including pneumatic classification for the production of asbestos fibre concentrate.

 

It is estimated that some 150 million tons of ore were extracted, providing 942,000 tons of asbestos fibre concentrate.

 

However, when operations at the mine ceased, the State was faced with a serious environmental problem. Because no restoration of the environment had taken place at the time and due to the lack of environmental legislation, the enormous dumps of waste which were created not only had an environmental impact but presented serious problems of stability. Fortunately for all, work began in 1995 on transforming the site of the mine with the aiming of stabilizing the waste dumps through the construction of benches and the reforestation of the area. Work is proceeding satisfactorily and is due to be completed in 2015.

 

 

Chromite Mine

 

The exploitation of chromium in Cyprus, in the form of chromite mining, dates from 1922 when some occasional small surface excavations were carried out in the Troodos region and the Limassol Forest. The systematic exploitation of chromites began in 1931 in the Troodos mountains, specifically at the Kokkinorotsos deposits, continuing later at the Kanoures (1939) and Hadjipavlou (1950) sites. These deposits are close to the top of Mount Olympus where harzburgite and dunite are found together and the average concentration of  Cr2O3 in the spinelium is around 52%.

 

Operations ceased in 1982 due to pressure on the commercial price of chromite which was being replaced for refractory purposes by other materials and by the appearance on the international market of cheap chromite from South Africa with new methods of producing ferrochrome.

 

For the extraction of the ore, underground methods were used, specifically by driving successive horizontal floors or storeys or filling the void with sandfill or hydraulic sandfill using cemented rockfill containing waste from the enrichment plants at Saint Nicholas of the Roof and Kakopetria. In a few isolated instances, the shrinkage method was used.

 

It is worth noting that for mining in the lowest gallery of the Kokkinorotsos deposit, attempts were made to use a tunnel boring machine while for the inside shafts a special raise borer was successfully used.

 

The enhancement methods that were applied were mainly gravitometric (heavy media drum and cyclones, vibrating classifiers, tables and variations of these). The ore supplying the enhancement plant had an average Cr2O3 concentration of 27% while it was 48% in the resulting products and as a natural by-product of Cypriot chromite it was destined mainly for refractory purposes.

 

During the exploitation of the aforementioned deposits, it is estimated that some 1,200,000 tons of ore were extracted, providing after processing around 560,000 tons of chromite concentrate. Mining research suggests that Kokkinorotsos and Hajipavlou still contain exploitable chromite deposits.