Application of ammonium bifluoride for chemical treatment of wells in underground uranium leaching

Improving the efficiency of borehole uranium recovery in difficult mining-and-geological conditions through the development of a new technology based on the intensification of geotechnological processes of in-situ uranium leaching, the selective effect of a new chemical reagents complex on a set of the mineralogical and particle-size distribution of the orebearing rocks of the productive horizon. Methods. Sampling of core material from host rocks of the Syr Darya depression uranium deposit. The content of uranium, calcium, aluminum, iron, magnesium, and carbonate content in the samples has been revealed by the spectral analysis method. The quantitative and qualitative parameters and peculiarities of the host minerals have been determined by the method of X-ray phase analysis. By testing particle-size distribution, the fractional parameters of core samples have been determined. Specifications have been developed, as well as laboratory experiment have been conducted on uranium leaching from core material in a dynamic mode in tubes, with the addition of selected chemical reagents with different modes. Findings. The aspects of borehole uranium recovery using sulfuric acid solutions as a solvent and the reasons that cause a decrease in geotechnological parameters in ores with low filtration characteristics have been determined. An effective method has been developed for intensifying borehole uranium recovery using superficially active substance (surfactants, SAS) in difficult mining-and-geological conditions, with an increased content of argillaceous and carbonate minerals, and low filtration host rocks properties. An efficient and economically feasible method for uranium leaching with sulfuric acid solutions with the addition of surfactants has been revealed and scientifically substantiated. Originality. The scientific novelty is in the fact that the selected surfactants added to sulfuric acid solutions increases the uranium content in the productive solution and the degree of economically feasible uranium recovery with reduced sulfuric acid consumption and the ratio of liquid to solid (L:S). Practical implications. The use of rational surfactants in uranium leaching makes it possible, in areas with low filtration characteristics, to reduce operating expenses for production by reducing the period of recovery, to increase the uranium content in the productive solution and the degree of recovery, as well as to reduce the consumption of sulfuric acid and sedimentation.

Section: Figure 3 Uranium Content In the Solution Depending On The Ratio Of L:smentioning

confidence: 98%

Research into leaching of uranium from core samples in tubes using surfactants

Rakishev¹,

Матаев²,

Kenzhetaev³

et al. 2020

“…Moreover, there is no available research identifying influence of sulfuric acid in a solution and oxygen saturation maintaining in the long term. Solution oxygenation using Venturi tube is proposed to avoid the disadvantages; increase uranium extraction; and reduce the time for a deposit mining [30], [31].…”

Section: Introductionmentioning

confidence: 99%

Analyzing changes in a leach solution oxygenation in the process of uranium ore borehole mining

Aben¹,

Toktaruly²,

Khairullayev³

et al. 2021

Purpose is to increase uranium content in a PR solution while developing a technique varying oxidation-reduction potential of a leach solution with its oxygenation and identify changes in the oxygenation depending upon sulfuric acid concentration as well as transportation distance of the solution. Methods. A laboratory facility, involving solution tank, pump, Venturi tube, tank to install oxygen analyzer, and a dump tank, has been manufactured under the lab conditions to determine a leach solution oxygenation taking into consideration its delivery rate, sulfuric acid concentration, and temporal preservation of the concentration. Solution flow velocity; the deli-vered solution volume; sulfuric acid concentration; and distance from oxygenation point to a seam changed and varied during the study. Oxygenation was measured with the help of AZ 8403 oximeter; IT-1101 device was used to measure pH value as well as oxidation-reduction potential (ORP). Findings. A technique for a leach solution oxygenation and results of laboratory tests to identify influence of a sulfuric acid as well as transportation distance of a solution on oxygen concentration in the solution have been represented. It has been determined that Venturi tube helps oxygenize a leach solution; in this context, maximum oxygen concentration is achieved if a flow velocity is optimum one. It has been specified that a solution oxygenating depends upon a sulfuric acid concentration decreasing moderately with the increasing distance of the solution transportation. Originality.Following new dependencies have been determined: oxygen concentration in a solution upon a flow velocity and solution volume; and oxygen concentration in a solution upon distance from concentration place and sulfuric acid concentration. Practical implications.A leach solution oxygenation results in the increased oxidation-reduction potential and in the increased content of a useful component in the pregnant solution respectively. The proposed technique is notable for its low capital spending. Moreover, it is integrated easily into the available system being absolutely environmentally friendly.

“…Underground leaching of uranium is carried out by selective its dissolution with chemical reagents from ores at the place of their occurrence and subsequent extraction from uranium-containing solutions. Despite all the advantages, when using a borehole in-situ leaching of uranium, there is still a number of unresolved problems, one of which is to prolong the interrepair cycle of production wells performance, as well as to increase the ratio of uranium recovery (Zabel'skiy, 1981;Golik & Kultyshev, 2011;Yusupov, Elzhanov, Aliev, & Dzhakupov, 2017;Shcherbakov, Tymchenko, Buhrym, & Klymenko, 2019).…”

Section: Introductionmentioning

confidence: 99%

Study of change in the leaching solution activity after treatment with a cavitator

Aben¹,

Markenbayev²,

Khairullaev³

et al. 2019

Increasing the valuable component content in a pregnant solution due to the activation of leaching solution with cavitation treatment in case of the borehole in-situ leaching (ISL). Methods.To obtain the cavitation effect, a laboratory cavitation plant has been produced. Studies on the sulphuric acid solution activation by means of cavitation were conducted using solutions with 10 g/l of acid content. Studies of changing the sulphuric acid solution activity during treatment with a cavitator were conducted for 3 minutes (24 passes through the cavitator), 5 minutes (40 passes), 10 minutes (80 passes) and 20 minutes (160 passes). The content in the solution of the valuable component was analysed using a KFK-3-"ZOMS" photoelectric photometer.Findings. The laboratory studies have been performed to set the influence of the cavitation process on the leaching solution activity at various degrees of activation and time of reaction. The studies have established that in order to activate the leaching solution, it is proposed to carry out cavitation treatment of sulphuric acid before to additionally fortify the mother solution, which helps to increase its activity. The solution activation leads to an increase in the valuable component content from 18 to 26% in the pregnant solution and its activity is maintained for a long time (up to 30 days).Originality. New dependences have been obtained reflecting the nature of changing the valuable component content in the pregnant solution on the reaction time and the degree of solution activation. Practical implications.The proposed activation method leads to an increase in the valuable component content in the pregnant solution compared to the basic technology, therewith, the activity is maintained for a long time. The proposed technology is characterized by low capital costs, is easily integrated into the existing system and is absolutely environmentally friendly.