Molycorp, Inc.’s Questa Mine plans to switch from gravity draw in Block 1 to a load-haul-dump (LHD) draw system in the East and West blocks of the D Orebody. Changes in mining method require modifying the support design. This paper summarizes the numerical ...

The evolution of surface subsidence is an important focus of study above Molycorp, Inc.’s newest block cave at the Questa molybdenum mine near Taos, New Mexico. The case study compares mature glory hole subsidence over the Goathill Orebody and subsidence emerging ...

The Molycorp, Inc., Questa Mine, located in New Mexico, currently mines using a gravity-draw panel cave to extract molybdenum sulfide ore from the 600-m-deep D Orebody. Prior to initial development, geotechnical studies were undertaken to predict ground response ...

High horizontal stresses were recognized to impact roof stability more than 60 years ago. Since then, numerous measurements associated high horizontal stresses with difficult ground conditions. This paper presents case histories illustrating the practical ...

The significance of a massive sandstone unit in the immediate roof to longwall support weighting is well known. If the unit lies in the main roof above the zone of caving, its influence becomes more difficult to calculate using traditional methods. Much of ...