VNIPIpromtekhnologii JSC, Moscow, Russia:

A. V. Gladyshev, CEO, Gladyshev.A.V@vnipipt.ru

The age of uranium ore and the water exchange intensity in ore-bearing strata has a direct effect on radiology of hydrogenous uranium deposits suitable for the in-situ leaching, connected with radioactive balances in the U–Ra systems (830 thousand years) and Ra–Rn systems (23 days), used in traditional gamma logging in appraisal of uranium resources. However, this method is insufficiently reliable sometimes, for instance, in Khiagda ore province. Ore dating by different methods yields a time span of 12–1.5 million years. The traditional gamma logging approach to determining uranium content in Khiagda ore shows the upward flow of radon in the zones of highly jointed and discontinuous zones in granite basement. Ra–Rn equilibrium was unfound even on the 54^th day of the gamma log surveys. The article describes the prompt fission neutron logging technique (PFNL). This method uses the property of isotope 235U to split intensively in the field of slow neutrons, with emission of fission neutrons. Currently, this method is the main technique of direct uranium detection in ore deposits during in-situ leaching. The physical processes of emitting of prompt neutrons by isotope Uranium-235 in radiation of an ore body by thermal neutrons from a borehole impulse neutron generator are described. The case-studies of finding reliable variables to estimate ore-bearing sites at Khiagda deposit.

1. Mashkovtsev G. A., Konstantinov A. K., Miguta A. K., Shumilin M. V., Shchetochkin V. N. Uranium Wealth of Russia. Moscow : VIMS, 2010. 850 p.
2. Karimov Kh. K., Bobonorov N. S., Tolstov E. A. et al. Uchkuduk type of uranium deposits in the Republic of Uzbekistan. Tashkent : Fan, 1996. 340 p.
3. Aubikarov Kh. B., Vreshkov A. F., Lukhtin V. F., Petrov N. N., Plekhanov V. N. et al. Uranium deposits of Kazakhstan (exogenous). Almaty : Gylym, 1995. 264 p.
4. Oryngozhin E. S., Fedorov E. V., Alisheva Zh. N., Mitishova N. A. In-situ leaching technology for uranium deposits. Eurasian Mining. 2021. No. 2. pp. 31–35. DOI: 10.17580/em.2021.02.07
5. Golubev V. N., Chernyshev I. V., Chugaev A. V., Eremina A. V., Baranova A. N. et al. U–Pb Systems and U Isotopic Composition of the Sandstone-Hosted Paleovalley Dybryn Uranium Deposit, Vitim Uranium District, Russia. Geology of Ore Deposits. 2013. Vol. 55, No. 6. pp. 399–410.
6. Golubev V. N., Tarasov N. N., Chernyshev I. V., Chugaev A. V., Ochirova G. V. et al. Post-Ore Processes of Uranium Migration in the Sandstone-Hosted Type Deposits: 234U/238U, 238U/235U and U–Pb Systematics of Ores of the Namaru Deposit, Vitim District, Northern Transbaikalia. Geology of Ore Deposits. 2021. Vol. 63, No. 4. pp. 287–299.
7. Golubev V. N., Chernyshev I. V., Kochkin B. T., Tarasov N. N., Ochirova G. V. et al. Uranium Isotope Variations (234U/238U and 238U/235U) and Behavior of U-Pb Isotope System in the Vershinnoe Sandstone-Type Uranium Deposit, Vitim Uranium Ore District, Russia. Journal of Earth Science. 2022. Vol. 33, No. 2. pp. 317–324.
8. Solodov I. N. (Ed.). Uranium Production by In-Situ Leaching in the Permafrost Zone. Moscow–Chita : ZetaPrint, 2022. 183 p.
9. Domarenko V. A., Kramorenko S. V., Chernev E. M. Uranium and radium behavior by ore forming in the Dybryn deposit (Buryatia). Noble, Rare and Radioactive Elements in Ore-Forming Systems : Proceedings of All-Russian Conference with International Participation. Novosibirsk : INGG SO RAN, 2014. pp. 210–216.
10. Minosyants A. R., Solodov I. N., Gurulev E. A. Application of instantaneous fission neutron logging at different stages of ISL uranium mining. Razvedka i okhrana nedr. 2019. No. 7. pp. 22–30.
11. Karamushka V. P., Kamnev E. N., Kuzin R. E. Reclamation of Uranium Production and Processing Facilities. Moscow : Gornaya kniga, 2014. 183 p.
12. Toktaruly B., Bayeshov A., Aben Y., Suleimenov Sh. K. Effect of process solution saturation with oxygen on uranium in-situ leaching performance. Eurasian Mining. 2022. No. 2. pp. 50–53. DOI: 10.17580/em.2022.02.12
13. Hiam-Galvez D., Gerber E., Perkrul J. In situ recovery (ISR)—The permitting challenge. ALTA 2020: Uranium Ore Processing. Perth : ALTA Metallurgical Services, 2020.
14. Revuelta M. B. Mineral Resources: From Exploration to Sustainability Assessment. Cham : Springer, 2018. 653 p.
15. Tolkachev V. A., Maynikov D. V., Paskhin N. P. Understanding the clarification process applicable to injection solutions generated by uranium in-situ leaching sites. Tsvetnye Metally. 2019. No. 6. pp. 39–44. DOI: 10.17580/tsm.2019.06.06
16. Khaykovich I. M., Mats N. A., Ganichev G. I. Nuclear Logging Methods for Uranium Deposits. Saint-Petersburg : FGUNPP Geologorazvedka, 2017. 314 p.
17. Khaykovich I. M., Ganichev G. I. Prompt Fission Neutron Logging Manual for Uranium Deposits Using KND-M Procedure and Equipment (AINK-49 Versions). Saint-Petersburg : FGUNPP Geologorazvedka, 2014. 61 p.
18. Kliger K. G., Martynenko V. G., Minosyants A. R. et al. Downhole neutron generator assembly for logging uranium ores. Patent RF, No. 152266. Applied: 25.12.2014. Published: 10.05.2015. Bulletin No. 13.
19. Solodov I. N., Gladyshev A. V., Ivanov A. G. Experience for extraction of uranium by isl method in kriolitozone. Razvedka i okhrana nedr. 2017. No. 11. pp. 65–70.