CHARLESTON, W.Va. -- Federal mining regulators issued 150 citations during December impact inspections.The U.S. Mine Safety and Health Administration said Thursday it also issued nine orders following inspections at eight coal mines and three other mines.MSHA issued 13 citations and five orders at Dorchester Enterprises Inc.'s No. 4 Mine in Wise County, Va. Violations included failing to follow an approved ventilation plan and accumulation of combustible material.MSHA also issued 28 citations at the Azarco LLC Ray Mine, a surface copper ore operation in Gila County, Ariz. Among the violations were exposing miners to fall hazards and failing to provide insulating material to prevent electrical shock. The inspections began in 2010 after a mine explosion in West Virginia that killed 29 coal miners.