Abstract: The roof of a heading cut by a continuous mining machine is supported by cantilevered roof beams forming part of a shield. There are at least two sets of roof beams which can be raised and lowered separately by means of hydraulic rams. When one set is lowered and the other set is raised, the lowered set can be pushed forward against the raised set by means of hydraulic rams. The cantilevered roof beams extend far enough forward to support the roof over the driving position of the continuous mining machine. The width of the shield should be less than the width of the mining machine, so that the shield can advance along the heading cut by the mining machine. Furthermore, the shield includes a conveyor for conveying the mined material from the mining machine backwards to a shuttle car or other conveying system.

Abstract: In the solution mining of uranium ores using an aqueous ammonium carbonate leaching solution containing hydrogen peroxide and/or molecular oxygen as oxidant, permeability of the ore formation during the leaching operation is maintained or improved by including a small amount of alkali metal silicate dissolved in the leaching solution. The silicate also improves the stability of the oxidant in many instances.

Abstract: In a process for the solution mining of a uranium ore formation using an aqueous alkaline carbonate leaching solution containing hydrogen peroxide as oxidant, the solution is passed through the ore formation in the presence of an alkylidene-1,1-diphosphonic acid. Such an acid has been found to be unique in its capability for stabilizing the peroxide against decomposition in the presence of the uranium ore.