Geochemical reactions altering the mineralogical and multiscale pore characteristics of uranium-bearing reservoirs during CO2 + O2in situ leaching

CO 2 + O in situ leaching has been extensively applied uranium recovery sandstone-type deposits of China. The geochemical processes impact and constrain the reaction solution migration; thus, it is necessary to study –water–rock process its influence on physical properties uranium-bearing reservoirs. In this work, a simulation experiment was carried out, mineralogical multiscale pore characteristics typical samples before after were compared by X-ray diffraction high-pressure mercury intrusion porosimetry (HPMIP). results show that complicated effects mineral compositions due various modes types. After reaction, femic minerals decrease clay coarse sandstone, medium fine siltstone increase, while sandy mudstone contrary changing trend. decreases total volume reservoirs then promotes transformation from small scale large scale. fractal dimensions macropores are decreased, mesopores, transition pores, micropores increased. felsic carbonate dissolution, secondary precipitate, swelling, particle migration simultaneously present process, which exhibit positive negative for dissolution may improve reservoir permeability certain degree, siltation effect will gradually reveal with extension leaching. This research provide deep understanding property response during indicate direction efficient resources.