Blasting rock by expansion of ice - uses object cooled in liquid air placed in water filled bore to cause sudden expansion

摘要

The procedure for blasting rock or stone involves sudden and a strong expansion of the ice, achieved by immersing in water an object which was previously cooled in liquid air to a very low temperature. The ice formation takes place in an explosive manner with strong shock-type expansion of the ice. A small metal rod, or pebble, or other object, cooled in liquid air, is inserted in a hole drilled previously in the rock. The expenditure on liquefying a small amount of air is negligible compared to the cost of transporting and stoning in warehouses, broken rock, used for road building.