Following a small-scale wedge failure at Yukon Zinc＇s Wolverine Mine in Yukon, Canada, a vibration monitoring program was added to the existing rockbolt pull testing regime. The failure in the 1150 drift occurred aft...Following a small-scale wedge failure at Yukon Zinc＇s Wolverine Mine in Yukon, Canada, a vibration monitoring program was added to the existing rockbolt pull testing regime. The failure in the 1150 drift occurred after numerous successive blasts in an adjacent tunnel had loosened friction bolts passing through an unmapped fault. Analysis of blasting vibration revealed that support integrity is not compromised unless there is a geological structure to act as a failure plane. The peak particle velocity（PPV） rarely exceeded 250 mm/s with a frequency larger than 50 Hz. As expected, blasting more competent rock resulted in higher PPVs. In such cases, reducing the round length from 3.5 m to 2.0 m was an effective means of limiting potential rock mass and support damage.展开更多
Recently,Jinduicheng Molybdenum Group(JMG)issued the 13th Five-Year Development Plan(hereinafter referred to as the'Development Plan')The Development Plan proposes that the company generate an operating income...Recently,Jinduicheng Molybdenum Group(JMG)issued the 13th Five-Year Development Plan(hereinafter referred to as the'Development Plan')The Development Plan proposes that the company generate an operating income of RMB 30 billion by the end of 2020 and build itself into a comprehensive mining group with international competitiveness.展开更多
Recently,Jinduicheng Molybdenum Group(JMG)issued the 13th Five-Year Development Plan(hereinafter referred to as the'Development Plan')The Development Plan proposes that the company generate an operating income...Recently,Jinduicheng Molybdenum Group(JMG)issued the 13th Five-Year Development Plan(hereinafter referred to as the'Development Plan')The Development Plan proposes that the company generate an operating income of RMB 30 billion by the end of 2020 and build itself into a comprehensive mining group with international competitiveness.展开更多
文摘Following a small-scale wedge failure at Yukon Zinc＇s Wolverine Mine in Yukon, Canada, a vibration monitoring program was added to the existing rockbolt pull testing regime. The failure in the 1150 drift occurred after numerous successive blasts in an adjacent tunnel had loosened friction bolts passing through an unmapped fault. Analysis of blasting vibration revealed that support integrity is not compromised unless there is a geological structure to act as a failure plane. The peak particle velocity（PPV） rarely exceeded 250 mm/s with a frequency larger than 50 Hz. As expected, blasting more competent rock resulted in higher PPVs. In such cases, reducing the round length from 3.5 m to 2.0 m was an effective means of limiting potential rock mass and support damage.
文摘Recently,Jinduicheng Molybdenum Group(JMG)issued the 13th Five-Year Development Plan(hereinafter referred to as the'Development Plan')The Development Plan proposes that the company generate an operating income of RMB 30 billion by the end of 2020 and build itself into a comprehensive mining group with international competitiveness.
文摘Recently,Jinduicheng Molybdenum Group(JMG)issued the 13th Five-Year Development Plan(hereinafter referred to as the'Development Plan')The Development Plan proposes that the company generate an operating income of RMB 30 billion by the end of 2020 and build itself into a comprehensive mining group with international competitiveness.
