roof supports longwall

  • Advancements in Longwall Roof Supports | Coal Age

    Advancements in Longwall Roof Supports. "First is operational experience. Joy longwall roof supports are involved in more than 60% of the active longwall mining faces currently in operation in Australia and more than half of all those in the United States, and complete Joy longwall mining systems comprise more than 70% of the single-manufacturer longwalls operating today.

  • Joy Powered Roof Supports - Mining Corp.

    Joy powered roof supports, for high-capacity longwall applications, are custom designed to meet your exacting cycle and operating requirements: Ratings up to 1,750 tonnes. Widths of 1.5, 1.75, and 2.05 meters. Heights from 0.8 to 7.8 meters. Leg bore sizes ranging from 125 to 480 mm.

  • Longwall mining - Wikipedia

    Longwall has better resource recovery (about 80% compared with about 60% for room and pillar method, fewer roof support consumables are needed, higher volume coal clearance systems, minimal manual handling and safety of the miners is enhanced by the fact that they are always under the hydraulic roof supports when they are extracting coal.

  • Concrete crib blocks bolster longwall roof support ...

    The US Bureau of Mines, in researching alternatives to traditional roof support methods, designed and installed high-strength cable supports to improve the stability of longwall gate road and bleeder entries in a Western US coal mine.

  • The Principle of Longwall Top Coal Caving (LTCC) - YouTubeClick to view on Bing3:58

    Apr 30, 2015 · Longwall Top Coal Caving (LTCC) roof supports allow mining of seams seams thicker than 6 meters (20 feet).