“Priargunsky Industrial Mining and Chemical Union” JSC (Krasnokamensk, Russia):

Litvinenko V. G., Chief Technologist, Doctor of Engineering Sciences, e-mail: LitvinenkoVG@ppgho.ru

Sheludchenko V. G., Deputy Head of Central Research Laboratory, Candidate of Engineering Sciences

Filonenko V. S., Head of Chemical and Toxicological Laboratory (Central Research Laboratory)

Researches and semi-industrial testings were carried out for the choice of rational mode of agitational uranium leaching from raw materials of Priargunsky Industrial Mining and Chemical Union with optimization of coarseness of ground ore and decreasing of oxidant consumption. Final pH and redox potential of the process accounted 1.8 units and ~475 mV, respectively, in the basic mode of uranium leaching from raw materials with the solid substance coarseness to ~3% of +0.1 mm of the grain size fraction. At the same time, consumption of sulphuric acid was stated at the level of 90 kg/t, and consumption of MnO₂ was stated at the level of 5.5 kg/t. There were further observed the indices about uranium opening with the stepwise decreasing of final pH of pulp to 1.5–1.2–0.9 units. Redox potential of the process was similar to the basic mode. Considering the basic mode, increasing of introduction of sulphuric acid was stated at ~12%, ~23% and ~44%, respectively. At the same time, decreasing of the consumption of manganese dioxide was ~15%, ~30% and ~75%. There was also defined the increasing of extraction of valuable component into the solution by 0.6–1.6%. Semi-industrial ore processing testings with increasing of ground ore coarseness have shown, that technology with increasing of content of particles (+0.1 mm of the grain size fraction) in thickened suspension from ~3% to 6–7% and further — to 10–12% makes it possible to do the following operations:
— increasing of productivity of ore grinding production stage;
— decreasing of consumption of flocculent, grinding balls and electric power.
Uranium leaching from obtained pulp with 1.2 units of the final pH value of the process provides the economy of manganese dioxide from the material (6–7% coarseness of +0.1 mm of the grain size fraction) by ~30% with increasing of acid consumption by ~20%. Opening of raw materials with the content of +0.1 mm of the grain size fraction at the level of 10 0–12% makes it possible to decrease the consumption of MnO2 by ~40% with increasing of H₂SO₄ consumption by ~10%.