| 摘要 |
<p>A method of underground gasification of coal involves drilling at least two boreholes (8, 9) along the length of the seam, one borehole (8) serving to feed oxidant air or oxygen to the combustion zone (6), the other borehole (9) being to recover combustible gas from the combustion zone. The problem of back-burning of coal along the oxidant borehole is tackled by continuously or intermittently injecting water along the borehole.</p> |
