Backfilling in High Temperature and Hard Rock Mining in Toyoha Mine, Japan

摘要

The Toyoha mine is operated under an extremely high rock temperature. The geothermal heat is 10 to 20 times more active than the average in the Japanese Islands. The highest temperature ever observed in exploration drill holes is 242℃ that must be equivalent to those of the geothermal fluids utilized for power generation in Japan. In order to improve the underground climate, the mine decided to introduce paste backfilling and effectively reduce the heat flows from the mined-out stopes. Underground flow tests were carried out and evaluations of the energy saving effects by paste backfilling were made.