Three things to look for in underground seals

The mining of coal underground has historically been recognised as a hazardous occupation.

It is a universally recognised principle of underground coal mine safety that there must be proper ventilation of the mine.

Indeed, no aspect of safety in underground coal mining is more fundamental than proper ventilation.

Failure of the ventilation system or failure of underground seals can lead to multiple fatalities and closure of a mine. Examples include Moura No. 2 (Queensland, 1994) and Sago (the United States, 2006).

It   is   critical to   maintain   an   effective,  safe   and   efficient   ventilation   system   in   an underground  coal  mine,  and  ventilation  control  devices  (VCDs) play  an  essential  role  in  mine operations  and  safety.

The effectiveness of ventilation control devices (VCDs) to safely resist explosions during their intended life is important.

This functionality depends on the ability of the VCDs and in particular seals to withstand changes in the behaviour of the strata, particularly where longwall abutments influence the stress regime in and around the chain pillars.

During the normal course of underground coal mining, it sometimes becomes necessary to install permanent seals to isolate abandoned or worked out areas of the mine.

This practice eliminates the need to ventilate those areas. Seals may also be used to isolate mine fires or areas liable to spontaneous combustion.

To effectively isolate areas within a mine, a seal should:

  • prevent toxic and/or flammable gases from entering active workings and oxygen from entering the sealed areas
  • be capable of preventing an explosion initiated on one side from propagating to the other side, and
  • continue its intended function when subjected to heat (AS 1530.4 – 1990) time-temperature heat input (Tuchman and Brinkley, 1990).

For more than 20 years, Minova has manufactured a range of cementitious and steel fabricated systems that are used in the design and construction of underground mine ventilation structures and bulkheads.

The company offers vast experience and capability in engineering, design, product manufacture, fabrication and contract installation of VCD’s.

Minova has successfully developed and implemented many specific devices for individual customer requirements.

Visit to learn more and download Minova’s technical papers.

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