Application of radio-wave geointoscopy method to study the nature of spreading the solutions in the process of uranium underground leaching

Abstract

Purpose. Assessment of the effectiveness of using the method of radio-wave geointoscopy of the inter-well space for three-dimensional mapping of the zone of the leaching solution actual propagation in the process of uranium mining by the method of underground leaching. Methods. Experimental-industrial studies of the leaching process are conducted at technological block 68 of the Semizbay deposit (Kazakhstan). In experimental studies, special equipment is used for conducting radio-wave geointoscopy. Inter-well measurements are performed using the RVGI-06 equipment. The observations are conducted in a fan pattern within the filter section. The step between adjacent points along the wellbore is 1 m. At different stages of mining the technological block, maps of geoelectric resistivity have been compiled, with the help of which a comparative analysis is performed. Findings. A tendency to an increase in the area of acidic solutions propagation over time has been revealed by comparing the fragments of RVGI geoelectric map at different stages of mining the block. The influence of a heterogeneous geological structure on the uniformity of the leaching solutions propagation has been proved. It has been determined that the resolving power of the radio-wave geointoscopy method is sufficient to detect changes in geoelectric conditions at small monitoring cycles in time. The spatial-temporal change in the front of the leaching solutions propagation makes it possible to determine the prevailing directions of solutions propagation and to assess the filtration characteristics of rocks. Originality. The patterns have been determined of the leaching solutions propagation over time from the beginning of block acidification to active leaching. The first attempts have been made to use the geophysical well logging method in the practice of uranium mining by In-Situ Leaching (ISL) method. Practical implications. Monitoring studies by radio-wave geointoscopy method at the stage of passive acidification can be re-commended for further experimental and scientific testing at technological blocks of the Semizbay deposit for a quantitative assessment of the filtration characteristics of rocks and the dynamics of the acidification process development, as well as for the development of well-grounded recommendations on the optimal scheme for mining the blocks in specific geotechnical conditions.