| 释义 |
free-swelling index free-swelling index[′frē ‚swel·iŋ ′in‚deks] (engineering) A test for measuring the free-swelling properties of coal; consists of heating 1 gram of pulverized coal in a silica crucible over a gas flame under prescribed conditions to form a coke button, the size and shape of which are then compared with a series of standard profiles numbered 1 to 9 in increasing order of swelling. |