Наведено дослідження кінетики вилуговування Mn, Ni, Cu, Pb, Fe із матеріалів хвостосховищ «Дніпровське» і «Центральний яр». Експерименти з вилуговування важких металів проводили за методикою визначення швидкості вилуговування радіонуклідів із радіоактивних відходів (ГОСТ 29114-91). За отриманими даними обчислили константи швидкості вилуговування важких металів із твердої матриці та константи їх виходу у розчин.
Mining and processing of uranium ores associated with many environmental problems. Along with the pollution of natural radionuclides environment, waste tailings uranium processing industry is also a source of contamination of ground and surface waters with heavy metals. Tailing waste on processing of uranium former «Prydniprovsky chemical plant» studied only in terms of distribution and migration ability of radionuclides. Any data on migration ability of heavy metals, but their content in the solid phase of waste and natural waters is not available.
Purpose of work is study the kinetics of leaching of metals from tailings materials industry in uranium processing.
In this paper deals with the kinetics of leaching of Mn, Ni, Cu, Pb, Fe material from tailing «Dneprovske» and «Central yar» Experiment with the leaching of heavy metals was carried out by the method of determining the rate of leaching of radionuclides from radioactive waste (GOST 29114-91). From the data obtained were calculated rate constant leaching of heavy metals from a solid matrix and constant release of their solution.
The results showed that the rate of leaching of heavy metals from tailings samples «Central yar» is almost an order of magnitude higher than samples from tailings «Dniprovske». This can be caused by several factors, including the first differences of the material composition of waste materials, physical and chemical conditions that occur in the tailing. In particular, the tailings are significantly different for the acid-alkaline conditions: the tailing «Central yar» pH are acidic or weakly acidic region, while in tailing «Dniprovske» – in near neutral or even slightly alkaline in. For the lower horizons of the studied both tailing characteristic are lowest rate of leaching of heavy metals. This is especially noticeable for the sample tailing «Dniprovske» 18,7…19,2 m of depth. This can be explained by the fact that the lowest horizon from which sampling was carried out, is underlain by breeds and contain no technogenic waste. The exception іs the lead (plumbum), which is the lowest rate of leaching tailings sample «Dniprovske» 14,8…15,2 m of depth. In tailing «Central yar» migration ability of metals is decreases in the number Mn > Fe > Pb > Ni > Cu. Such a trend is observed for all samples of the tailings. As for tailing «Dniprovske”, a series of migration ability of heavy metals can be set as follows: Mn > Fe ≈ Pb > Cu. Speed Ni leaching into the solution of tailings material «Dniprovske» significantly decreases with depth compared with other metals, so each patient horizon of the tailing position of nickel in some migration ability of metals will be different. The difference between these two tailings on the migration behavior of nickel can be explained by several factors, which are mainly caused by chemical and mineral composition of waste. Also play an important role physical (porosity, humidity) and water (permeability, swelling, filtration coefficient) properties of rocks contained in the tailing. However, these issues have not been fully addressed and require detailed study.
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