Koch freezing process

Koch freezing process

[′kōk ′frēz·iŋ ‚prä·səs]
(mining engineering)
A process used to sink a shaft through a formation such as clay that will not sustain a shaft; magnesium chloride cooled to about -30°C is circulated through pipes sunk in the ground until the ground is frozen.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.