PL154223B1 - Method and agent to combatting coal dust explosions in underground mine excavations - Google Patents

Description

PATENT DESCRIPTION

Additional patent to patent no. Filed: 87 03 02 / p. 264385 /

Priority Application announced: 88 09

The patent description was published:

1991 11 29

154 223

Int. Cl. ⁵ E21F 5/00

Creators of the invention: Bronisław Lisiecki, Tadeusz Zygadłowicz, Paweł Krzystolik,

Bolesław Kozłowski, Eugeniusz Raęsgus, Marian Filipek, Tadeusz Demel, Kazimierz Lebecki, Bogdan Łulasik, Piotr Makselon, Eugeniusz Kurek, Erwin Kozioł

The holder of the patent: Wieczorek Coal Mine, Katowice / Poland /

METHOD AND MEANS OF SIGHTED COAL DUST EXPLOSION IN UNDERGROUND MINING WILLS

The subject of the invention is a method and a measure for combating coal dust explosions in underground mining excavations.

There are known methods of combating coal dust explosions in mining excavations, consisting in adding non-flammable stone dust containing at least 90% calcium carbonate to the pulverized coal dust in the excavations. This dust is poured out in the workings, mixing it with the residual needle dust so as to achieve 70-80% of the non-flammable solids content, or it is placed on explosion-proof dams in the amount of 200-400 kg per 1 m of the excavation cross-section. The action of stone dust during an explosion is to absorb heat from the burning coal grains and obstruct the access of oxygen to the flame. The efficiency of stone dust operation increases with its fragmentation, which for the produced dusts is such that the fraction content below 75 mm is at least 50%. Another known method is to sprinkle water on the spindles or to put water on dams.

There are also known methods of combating coal dust explosion by binding the dust with hygroscopic salts or specially prepared resins, which when added to the coal dust bind it, preventing the formation of flammable dust-air mixtures. These methods are described in patents 61,213 pt. Method of binding dust in coal mining - owner of Chernische Fabrik Kalk GmbH, Cologne / West Germany / and 96 096 Method of binding coal and stone dust in mining excavations - holder of a patent Silesian University of Technology in Gliwice Wincenty Pstrowski. Moreover, it is also known from the provisional patent No. 101 610 entitled A method of suppressing the explosion of coal dust in underground mining excavations by dusting the excavations with fly ash, which is a waste ash from power plants burning hard coal, taken from landfills / dumps /.

All the methods described above have problems, mainly due to the methods used

154 223

154 223 anti-explosive agents. They are costly and inconvenient to use. Carbonate rock dust ^^ a ^ nia must be specially produced and the achievement of the required minimum fineness requires considerable amounts of energy. Due to the need for special production, mining is constantly experiencing a lack of stone dust. Chemicals such as hygroscopic salts and resins require special treatment, are expensive, and their use accelerates the corrosion of machinery and equipment. Water cannot be used widely, because in many workings it dries up quickly, and its action on dams is effective only in inhibiting strong eruptions. The use of fly ash according to patent 101 610 is also disadvantageous, because it is collected from dumps. Such dust is lumpy and loses its basic anti-explosion properties due to the grinding of the dust.

The method according to the invention consists in pouring in the underground mining excavations and placing on the shelves of explosion-proof dams fly ash, obtained from power plants burning lignite and collected directly from the last collecting electrodes of electrostatic precipitators. This method guarantees the exact coverage of the workings with dust due to its fragmentation and poor hygroscopicity.

The medium according to the liquid ash, which is collected directly from the last collecting electrodes of the electrostatic precipitators of the brown coal power plants, contains not more than 2C% of crystalline silica and not more than 2% of combustible parts. The share of the grain fraction below 75 µm in the ash is higher than 70%.

This ash has an average of 10 times more calcium compounds than stone fly ash. It also does not lump, maintaining good properties to combat coal dust explosions in underground mining excavations.

Claims (2)

Patent Claims 1. A method of combating needle dust explosions in underground mining excavations, consisting in the construction of dust dams and dumping of dust in excavations, characterized by the fact that in excavations, fly ash is poured out and placed on shelves of explosion-proof dams, obtained from power plants burning brown coal, taken directly from last electrofilters collecting electrodes. 2.a agent for preventing coal dust explosions in underground mining excavations, characterized by the fact that it is fly ash obtained from lignite-burning power plants, taken directly from the last collecting electrodes of electrolytes, and containing not more than 20% of crystalline silica, less than 2% of parts combustible, and the particle size fraction below 75 IU is higher than 70%. Department of Publishing of the UP RP. Circulation 100 copies Price: PLN 3,000