Zircon sand often contains minerals such as kyanite, thorite and thorianite, which contain trace amounts of radioactive elements such as uranium and thorium. During the production of zirconium oxychloride, these radioactive elements are concentrated in the waste residue, which has certain recycling value. To meet the demands of comprehensive utilization and radioactive pollution control of such waste residues, the process conditions for extracting valuable elements such as uranium and thorium from the waste residues were studied, and the effects of different leaching factors and parameters on the leaching efficiency of uranium and thorium were investigated. The results show that under the conditions of sulfuric acid concentration of 4 mol/L, leaching time of 4 h, liquid volume to solid mass ratio of 4∶1, and leaching temperature of 90 ℃, the leaching rates of uranium and thorium reach 99.9% and 88.6%, respectively. The result is better.
| 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 |