The study aimed to determine a method for draining out of gases in mine sections. It included a preparation of openings, drilling of degassing holes on surface on another mine section prepared for actual mining, their connection to a degassing system, extension of methane and air mixture and periodic measurements of flow and concentration of methane in captured mixtures. Main and auxiliary systems of vacuum degassing were developed in the mine section during its mining. Using the main system, gas and air mixtures with a methane quality standard were extracted, and using the auxiliary system – mixtures were extracted from previously mined adjacent sections with a methane content below its explosion level. On previously mined sections those wells were used in order to extract methane. The wells were drilled on an existing mine section, methane content in a captured mixture of the main degassing system was maintained as at least 25-35 volume %, and in the auxiliary degassing system – less than 3.5 volume%. Degassing wells at previously mined sections were temporarily disconnected from the auxiliary degassing system if methane content in it below 3.0 volume%, and then connected again after a methane concentration increased up to 4.5 volume%. The authors concluded that safety of mining by gas factor at mine sections in development of gas-bearing coal beds was increased.
Authors: Ruban, A. D.; Zaburdyaev, V. S. ;Full Source: Russ. RU 2,439,331 (Cl. E21F7/00), 10 Jan 2012, Appl. 2,010,128,058, 7 Jul 2010; 6pp. (Russ) ;