坑道レシーバーの建設について

抄録

At the Kamioka Mine, Mitsui Mining & Smelting Company, now daily outputting 3600 metric tons of zinc and lead ores, two underground chambers of 8000 cubic meters capacity for compressed air and water have been constructed mainly for the following purposes.
1. To cut the electric peak load by 1100kW-1500kW by means of midnight driving of air compressors and shorter driving in the daytime.
2. To save another new 600HP compressor which would be required for the increasing production plan.
Before the construction work the writer had carefully investigated and determined the econamical size, type, details of the air receiver and leakage characteristics of the surround rocks, which are mostly granitic gneiss.
Contrary to expectation the constructed chamber showed conspicuous leakage of air through cracks and fissures, for which the conventional grouting work was proved useless. The writer had been able to solve this difficulty of the air tightening by using the water saturated with lime, from which CaCO₃ precipitates and fills the fissure, being combined with the natural CO₂ contained in the compressed air.
The writer thus proved that even in such strongly faulted rocks in this country, it is possible to make the air receiver of such a large capacity.