[en] Hydrogen peroxide has been widely used as an oxidant for in-place solution mining of low-grade uranium ores with ammonium bicarbonate. Recent laboratory column leaching experiments have shown that hydrogen peroxide--under accelerated flow conditions at least--appears to contribute to a partial loss of permeability, which varies with different ores. However, when small quantities of sodium silicate are added to the leach, the loss of permeability is largely prevented, or even reversed. With some ores, the silicate also helped to stabilize hydrogen peroxide against decomposition