Full resolution (JPEG) - On this page / på denna sida - VI. Mining and Metallurgical Industry. General Survey. By C. Sahlin - 1. Mining. By Valfrid Petersson
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vi. mining and metallurgical industry.
based on ammonium perchlorate, of Swedish make, named territe has come
into use alongside of gelatine dynamite.
Concerning the general effect of blasting in the Swedish ore mines the
amount of röck broken down varies on an average between 8 and 15 tons,
and, where circumstances are favourable, 20 to 25 tons per kilogram of
explosive, and between 2 and 3 up to 8 to 15 tons, and in the open-cuts in
the export fields between 10 and 20 tons per meter drilled.
Sivedish Hammer-drill Machine.
Mining Methods. The oldest method of mining employed in Swedish
ore mines is "pallbrytning" (underhand stoping) this ancient method is still
extentively employed. It is used principally in open-cut mines; for
underground mines nowadays it is chiefly the smaller mines that stick to it;
the bigger mines are going over to other methods.
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