著者

渡邊 慶輝

出版者

一般社団法人 資源・素材学会

雑誌

日本鉱業会誌 (ISSN:03694194)

巻号頁・発行日

vol.83, no.951, pp.895-901, 1967-07-25 (Released:2011-07-13)

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Since 1961 a series of tests for hydraulic mechanization of coal mine has been made by the Coal Mining Research Centre, Japan. And at the first trial in Meiho colliery it was succeeded in constructing a hydraulic model mine in which all mining processes such as getting, loading and tranportation of coal are carried out hydraulically. During the trial many problems to solve were found, but this new method proved of practical use. Thereafter trials were made at 12 coal mines, and several of those mines have adopted this new method commercially. Now 100, 000 tons/month of coal is produced by hydraulic mining in Japan.The productivity of hydraulic coal mining largely depends on the strength of coal. While in SSR the strength of coal is expressed by Protojakonow's index f1, in Japan friability index FD is used generally. And it was found that there is a relation of f1·FD=32. The pressure of water necessary to a hydraulic monitor P is expressed as a function of coal strength in the form P=K 1600/FD. K is a factor of fissures in a coal seam and is 1-1.3.Equipments for hydraulic mining have been much improved during trials. Above all efficiency of a hydraulic monitor has been raised.When hydraulic mining, commonly a monitor requires 2-3 m3/min water of 50-150 kg/cm2. Further tests of mining with higher pressure 200-400 kg/cm2 but smaller quantity of water 60-360 1/min were made. But this is applicable only to very friable coal. Now we are trying to combine the high pressure water jet with usual mining-or boring-machineries for the purpose of increasing their performances.There are two ways of hydraulic transportation. One way is pumping coal through a pump and another way is feeding coal into a pipeline with a coal feeder. Both ways were tested. The higher the lifting head of a pump becomes, the more the rotating part of the pump wears. Consequentry for high head hydraulic transportation a multi-pipe type coal feeder was invented. And the first trials of it was made at Yoshima colliery. The results revealed that it had the tranporting capacity of 100 t/h registering volume concentration 20%. Now the trial is continued at Sunagawa colliery. 256, 000 tons of coal were transported from the begining of last year up to March this year.