Surface Chemistry Modification of Rock Dust for Improved Dispersion and Coal Dust Explosion Prevention


Rock dust is applied in underground coal mines to prevent the propagation of coal dust explosions. The application is conducted either dry or wet. Both methods have advantages and disadvantages however the formation of caked rock dust particles is cited as a significant concern for wet applications. A study was conducted to evaluate the effect of modifying the rock dust particle surfaces to repel water and each other by the addition of oleic acid (OA) and sodium oleate (NaOL). At a NaOL dosage of 2 Ibs/ton, a contact angle of 112° was measured indicating strong surface hydrophobicity and ability to repel water. FTIR studies indicated a chemisorption mechanism which is necessary for long term stability of the surface modification. The dispersion rate of the modified rock dust samples was elevated by the application of both OA and NaOL thereby indicating a significant reduction or elimination of the detrimental effect of caking. Tests in an explosion chamber showed a 79% reduction in the dust explosion potential relative to untreated rock test applied by the wet technique.

Meeting Name

2015 SME Annual Conference and Expo and CMA 117th National Western Mining Conference - Mining: Navigating the Global Waters (2015: Denver, CO)


Mining Engineering

Keywords and Phrases

Coal; Coal Mines; Dispersion (Waves); Explosions; Rocks; Surface Chemistry; Surface Treatment; Underground Explosions, Coal Dust Explosions; Dispersion Rate; Dust Explosion; Explosion Chamber; Long Term Stability; Surface Hydrophobicity; Underground Coal Mine; Wet Techniques; Coal Dust

International Standard Book Number (ISBN)


Document Type

Article - Conference proceedings

Document Version


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© 2015 Society for Mining, Metallurgy and Exploration, All rights reserved.

Publication Date

01 Jan 2015

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