大江鉱山の開発と操業の合理化

抄録

Ohe Mine, situated in the south-western part of Hokkaido, have experienced ups and downs many times since opening.
At that time when our Hokushin Mining Co.succeeded management of the mine, in October 1953, it was very dull state due to ruin of mine, waste of installation and inactive market.
In order to restore and enlarge the mine production, we made untiring effort actively in general measurement and improvement of engineering-such as prospecting, mining and beneficiation.
The principal improvements are given as follows.
1) Precise surveying of geology and are deposits established clear theory that the are deposits were echelon-arrangement-composite vein repeating fissure forming and mineralization contained various sulfide ores and manganese ores.
2) We adopted the following prospecting method to confirm the whole feature of-thn deposits.
At first, prospecting gallery was drifted in the foot-wall, then cross-cut or boring holl were cut toward the hanging wall.
Thus, we could discover large quantity of are reserves during short time, and could find occurence of vein containing many various are minerals.
3) The concentration of stoping faces were performed, and shrinkage method was replaced with sand filllng stoping methgd, then, stoplng efficency was remarkably increased.
4) In the beneficiation, the concentrates of useful minerals such as gold and silver bearing galena, sphaierite, pyrite and rhodochrosite were effectively separated by adoption of sulfide flotation with soap flotation.
Then, the commercial are reserves increased remarkably, and it made able to enlarge the production scale.
5) To improve the quality of manganese concentrates, investigation of roasting method of the concentrates was successfuly carried out.
Since March 1958, roasting and sintering process by use of rotary kiln were operated, and grade of manganese concentrates advanced from 33% to 47% of Mn, then, economical value of the are rised evidently.
As the result, we have accomplished the stabilized production of present scale, 5, 000 tons of crude ore per month.Nowadays, we are planning the production-increase up to 10, 000 tons per month.