English to French Tech/Engineering Mining & Minerals / Gems open-ended

Can anyone translate ore Blanket in French? Thank you

The delayed draw application establishes an ore blanket or cushion above and behind the rings being blasted to protect the drawpoints being drawn. The methodology entails limiting draw of the blasted rings to 30% on the top level, 50% on the 2nd level and 90% on the 3rd level. On the assumption that general caving has been established by the time the 4th level mining commences the ore cushion can be drawn to a normal SLC cut off. The dilution in this process is considerably less and was nominally estimated at 10% ore with recovery, assuming the ore cushion is drawn on the 4th level estimated at 90% for the 4 levels combined