Pore characteristics and seepage simulation of sandstone-type uranium ore in the 512 deposit, Xinjiang

Abstract

Objective In situ leaching is a uranium extraction process in which a solution reacts with uranium-bearing minerals in a saturated aquifer and then uranium in the flowing solution is extracted through exchange. To understand the internal structure and seepage path of the 512 deposits, Methods representative wallrock and ore cores of the deposit were selected for CT scanning, and the pore throat parameters were obtained via image noise reduction filtering, image segmentation to extract pores, and the construction of pore network models. The changes in the absolute permeability, tortuosity and seepage velocity are simulated with Avizo software. Results The results showed that the porosity of the wallrock was 15.42%, the connected porosity was 9.61%, the ore porosity was 15.18%, the connected porosity was 13.82%, and the water permeability was better than that of the wallrock. The high-density materials in the wallrock are metal minerals, accounting for approximately 0.54%, and most of the high-density minerals in the ore are secondary uranium minerals, accounting for 1.06%. It can be fully in contact with the solution during the leaching process. Conclusion There is strong heterogeneity inside the pores, which causes the flow rate to gradually decrease in the flow path. The number of large pores connecting the wallrock and ore is greater than that of small pores, indicating that large pores are the main factors determining the degree of pore development. According to the velocity streamlines, although there is a blockage area in the wallrock and ore, the circulation area is dominant.

Keywords

• sandstone-type uranium deposit
• in-situ leaching of uranium
• ct scan
• pore characteristic
• seepage simulation
• 512 deposit, xinjiang