METHOD FOR POTASSIUM MINE PROTECTION AGAINST FLOODING Russian patent published in 2006 - IPC E21C41/20 

FIELD: mining, particularly underground potassium deposit development.

SUBSTANCE: method involves drilling exploratory holes and performing gamma-ray logging and neutron gamma-ray logging in the holes; determining a number of rock-salt layers in waterproofing formation, thickness of separate rock-salt layers and distance between above layers and roof of upper potassium formation to be excavated; comparing determined summary thickness of non-excavated rock-salt layers in waterproofing formation with minimal admissible summary thickness and determining possibility of cleaning work performing. Rock-salt layers arranged between potassium formation and located in crack-formation area and in mine roof caving area, as well as ones located into potassium formations having thickness of less than 0.5 m, comprising interlayers of dynamic rock-salt phases, interlayers of sylvinites, carnallite, anhydrite-clay and marly rock having thickness of less than 0.1 m, rock-salt layers in intermediate banks having thickness of not more than 0.5 m and rock-salt layers with production induced stratification of clay-marly rock comprising salt and fraying out under salt table are not taken into consideration. Thicknesses of layers arranged inside potassium formations are taken into consideration in calculations with two-fold reduction of actual thickness of above layers.

EFFECT: prevention of potassium mine flooding.