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758- ix. mining industry and metal production op sweden.
m O
being exported. The incomparably largest zinc-blende deposit Åmmeberg,
in the Län of Östergötland, is even owned by foreigners, namely by the
Belgian company Vieille Montagne. The Åmmeberg ore is roasted
there previous to exporting.
During the quinquennial periods 1861/1900, Sweden’s exports of zinc om
amounted in yearly averages to:
Average. Metric tons.
1861/65 .................... 3,716
1866/70.................... 11,998
1871/75.................... 11,778
Average. Metric tons.
1876/80.................... 18,761
1881/86.................... 22,165
1886/90 ................. 26,589
Average. Metric ton.
1891/95 .................... 29,0«
1896/00................... 44#7
In 1900.................... 40,879
The value of the exports of zinc ores in 1902 is estimated to 1,928,000
kronor. Of the total (43,813 tons), 29,929 tons were exported to Belgium,
7,395 tons to France, 1,425 tons to Germany, and 5,064 tons to the Netherlands.
Nickel. Nickel ore is found in several places in combination with
magnetic pyrites in such large quantities that it was formerly worked, but of låte
the miuing of this ore has ceased. The process of producing nickel at the two
nickel-works Klefva and Sågmyra in many respects resembled the old
copper-melting process: the removal of the greater amount of sulphur, arsenic, and
iron by repeated roastings and meltings, furthermore refining, roasting, and
reduction with charcoal, and finally the making of so-called pulverized nickel.
Cobalt occurs, though sparingly, in several places in the country, e. g. at
Tunaberg, Vena, and Gladhammar. Besides at these places, cobalt occurs in
considerable quantity together with copper ore at the Håkansboda and Riddarhyttan mines.
In melting these ores, cobalt is precipitated, together with the iron and some copper,
on the bottom of the furnace, forming so-called »nasar», which of låte has occasioned
the extraction of cobalt and copper by the wet process, by dissolving in diluted
sulphuric acid, and precipitation of both metals. Also this production has now ceased.
Gold is produced almost exclusively at the Falun copper tcorks by
the extracting of ore residues, the silver and copper having first been
extracted. Besides in certain shafts in the Stora Kopparberg mines (where
gold occurs native, sprinkled in quartz together with selenium-bismuth),
it also forms a constant constituent in all ore, both in the silicic
copper-pyrites and in the sulphur-pyrites to an amount of five grams per toil
(0*ooo5 %)■ The gold is extracted according to a Swedish method.
After the silver and copper have been extracted from the carefully
roasted ore, the remainder, which principally consists of quartz,
silicate, and oxide of iron, is treated with a diluted solution of
hypochlorite of lime, mixed with some hydrochloric or sulphuric acid, so that
free chlorine is generated, whereby the gold is dissolved (the MunkeU
process). From the solution of chloride of gold thus obtained, the gold
is precipitated with ferro-sulphate and plumbic acetate. The old Ädelfors
mines, which were given up in 1874, have from 1890 been worked by a
foreign company, which, however, also has abandoned the same. The
production of gold in the country during different periods is shown by
Table 111, on page 755. Of the total production of gold during 1902 (or
94-3 kilogram) no less than 92-5 kilog. were from the copper works in Falun.
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