Dust Conditions in Mine Shafts, Regulation of

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Dust Conditions in Mine Shafts, Regulation of

 

a system of legislative measures designed to prevent explosions of coal dust. These regulations are applied in mines in which the work seams are hazardous because of the possibility of coal-dust explosion. If seams present dust and gas hazards, both dust and gas conditions are subject to regulation. Dust-hazardous seams include seams of coal with a volatile combustible matter content of 15 percent or more (combustible shales) and seams of coal with a lower content of volatile matter (except anthracites, the dust of which is known to be nonexplosive); the explosiveness of coal has been established by laboratory tests.

There are a number of ways to regulate dust conditions in mine shafts. Dust removal, which is also used to deal with the hazards of dust inhalation, involves preliminary wetting of the coal seam with water before the coal is extracted. When machinery is being used and blastholes are being drilled, the coal is sprayed with water or an air-water mixture or the dust is drawn off by suction. The dust is removed from air flows by means of mist-sprayed curtains, and dust deposits are washed off the walls of workings with water or a wetting-agent solution, such as dibutyl. The workings are whitewashed with a solution of lime and cement. The explosiveness of settled dust may be neutralized by treatment with slate dust or by the use of water. Explosions can be localized by means of slate-dust and water barriers.

In addition, the following methods are employed along the face area of the developing excavation: (1) water-ampul tamping, (2) bonding of deposits of settled coal dust before blasting by spraying the face and the adjacent working area for 20 m with wetting-bonding solutions or paste, and (3) neutralization of the dust by means of water curtains created by exploding charges simultaneously in blastholes and water-filled polyethylene bags and containers.

The regulation of dust conditions differs in certain details in the mining of combustible shales, sulfur, and sulfur-pyrite ores and in coal-concentration plants.

REFERENCE

Preduprezhdenie vzryvov pyli v ugol’nykh i slantsevykh shakhtakh. Moscow, 1974.

S. IA. KHEIFITS

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.