To enhance the leachability of low-permeability uranium-bearing strata during in-situ leaching of uranium, biotite—a mineral commonly enriched in the Nalinggou sandstone type uranium deposit, which often leads to localized densification and impeded fluid flow—was systematically investigated for its dissolution behavior in the presence of three low-molecular-weight organic acids: citric acid, tartaric acid, and succinic acid. A comparative study was conducted through dissolution experiments and PHREEQC simulations, combined with analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analysis. The research focused on the mechanisms of structural alteration, cation release characteristics, and pore parameter evolution of biotite under varying organic acid concentrations. The results demonstrate that organic acids significantly enhance biotite dissolution, leading to increased cation release, aggravated crystal structure degradation, and expanded specific surface area and pore volume. These effects intensify with higher acid concentrations. Among the tested acids, tartaric acid exhibited the most pronounced dissolution effect, increasing the specific surface area from 4.071 8 m2/g to 9.184 5 m2/g. PHREEQC simulations revealed that organic acids effectively inhibit the precipitation of Al (OH)3 and iron oxides by complexing with Al3+ and Fe3+, thereby prolonging the mineral dissolution process. The study indicates that low-molecular-weight organic acids can improve the permeability of uranium-bearing layers by enhancing mineral dissolution and optimizing pore structure. These findings provide a theoretical foundation and technical support for improving uranium leachability.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |