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

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

Morozov A. A., Head of Central Research Laboratory, Candidate of Engineering Sciences

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

Extraction of metal into solution was 60–65% during two years of block stowage of coal face coarseness crude ore, containing ~0.08% of uranium. Heap leaching technology with washing and recrushing of ore to −100 mm made it possible to increase the extraction of uranium into the solution to 70%. Concentration plant was set into exploitation with application of new equipment — X ray radiometric separators. The scheme, applied for ore preparation, includes the following stages:
— washing and screening of raw materials with delivery of uranium concentrated throgh product (−5 mm coarseness) into the pulp process;

— delivery of raw materials with −200+40 mm of the grain size fraction to the X ray radiometric separation;
— delivery of raw materials with −40+5 mm of the grain size fraction, purified from clay and slimes, to the percolation leaching of uranium in the bings.
This technology excludes the colmatation of ore material and formation of water-proof zones in the bings; and provided the increasing of extraction of uranium into the solution to 75%. Fine grinding of ore, supplied to the heap leaching, makes it possible to increase the extraction of uranium to 85% from the ore with its initial content of 0.06– 0.07% during not more than a year of raw materials leaching. Material with the coarseness of less than 15, 10 and 5 mm can be directed into the heap lea ching process on various realization stages of technology of concentration and proces sing of poor ores. In whole, on the basis of the carried out researches and developments, there were defined the methods of intensification of the process of percolation leaching of uranium. Usage of these methods at Priargunsky Industrial Mining and Chemical Union makes it possible to increase the production capacity of ore processing complex and the ratio of usage of raw materials base of enterprise. It is also possible to decrease the cost price of final products.