Full resolution (JPEG) - On this page / på denna sida - VI. Mining and Metallurgical Industry. General Survey. By C. Sahlin - 1. Mining. By Valfrid Petersson
<< prev. page << föreg. sida << >> nästa sida >> next page >>
Below is the raw OCR text
from the above scanned image.
Do you see an error? Proofread the page now!
Här nedan syns maskintolkade texten från faksimilbilden ovan.
Ser du något fel? Korrekturläs sidan nu!
This page has never been proofread. / Denna sida har aldrig korrekturlästs.
-260
vi. mining and metallurgical industry.
houses and other buildings either electric lamps or Lux lamps are
employed. At the open cut works in the export fields electric incandescent
lamps are burnt during the dark hours.
Ore-Treatment. In most of the iron mines the separation of the
valuable minerals from the valueless material is carried out simply by
hand-sorting and hand-picking in rock-houses erected in the immediate
neighbourhood of the shaft-head. The small ores (syltan) is afterwards subjected
to washing and picking by hand.
Magnetic Ore-separator, system "G-röndal V"-
Since 1884, however, the washing process in several mines with
magnetic iron ore has been replaced by coarse separation with magnetic
ore separators (malmskil jar e). Besides the Wenström ore separator
which was the first emplos^ed, several more modern ore coarse
separators have come into use in recent years, such as the Landén-Josephson, the
Vulcanus, the Gröndal, and several others. The extent to which magnetic
coarse separation is carried on in Sweden will be realized by the fact that
in the course of the years from 1885 to 1913 3 892 699 tons of iron ore have
been produced by means of magnetic coarse separation. In 1913 magnetic
coarse separation was employed at 30 mines, and the output was 1 058 655
tons of ore.
At the end of the nineties the concentration (anrikning) process for
poor ores and ferriferous gangue began to make its way into Sweden, and
<< prev. page << föreg. sida << >> nästa sida >> next page >>
