Mining coal - Key potential environmental impacts

Wastes

The coal mining industry reuses and recycles materials and works with industry partners, such as electric utilities, to find new markets for waste byproducts. Here are some examples of these activities:

• recycling solid wastes
  Like other large industries, coal companies recycle solid wastes such as grease, drums, tires, wood and post-consumer goods. Consumable items like batteries and filters are also recycled.
  
  
• reusing waste oil
  Most liquid wastes at coal mines are generated from vehicles, energy facilities and equipment maintenance. Finding new opportunities to reuse or recycle these materials is part of effective waste management practices. Teck Cominco, for example, reuses waste oil to replace diesel fuel in the mine blasting process and in a dust suppressant for coal-carrying unit trains.
  
  
• environmentally friendly alternatives
  At one time, the industry used lubricants containing toxic compounds like lead. After being used, these components made the lubricants hazardous wastes. This meant they had to be handled carefully and shipped to the hazardous waste plant at Swan Hills, Alberta. Today coal mining companies replace these lubricants with environmentally friendly alternatives, such as citrus products, which can be safely disposed of in landfills.
  
  
• recovering ash byproducts
  Ash, the powder-like material left behind after coal is burned, used to be treated only as a waste product at coal-fired power plants. Now most Canadian coal-fired plants recycle the ash. Some of the ash (bottom ash) falls to the bottom of the furnace, where it is collected for removal to dump sites. Nearly all the remaining airborne ash (fly ash) is removed by electrostatic precipitators or fabric filters called “bag houses”. Recovered ash is used as backfill at the mine site or sold for use in the manufacture of cement. It can also be used in other environmental projects, such as liquid waste stabilization.