PROLONGING INTERREPAIR CYCLES OF IN-SITU LEACHING URANIUM WELLS  USING A SPECIALIZED REAGENT

All uranium production in the Republic of Kazakhstan is conducted using in-situ leaching (ISL) technology. One of the major challenges associated with this mining method is the reduction in the operational life of process wells due to clogging of well screens and the near-wellbore formation zone. Existing well rehabilitation methods often fail to provide satisfactory results, as their effectiveness is frequently limited and the achieved improvements are typically short-lived.

The objective of this study was to develop a theoretical framework and evaluate the effectiveness of a specialized inhibitor-based reagent for extending the operating cycle of process wells.

Theoretical and laboratory investigations employing an inhibitor-dissolver reagent demonstrated enhanced dissolution of calcium-bearing deposits, thereby reducing the intensity of clogging within well screens and the near-wellbore zone. Relationships were established between calcium dissolution efficiency and inhibitor concentration in the leaching solution during uranium recovery, as well as between inhibitor dosage and the operating cycle of process wells. The preferential dissolution of calcium ions was achieved at an inhibitor concentration of 2%.

Pilot-scale field tests conducted at a uranium ISL operation demonstrated improved leaching performance owing to the extension of well operating cycles following inhibitor application. Compared with the conventional technology, the proposed approach improved uranium production efficiency by up to 30% on average.