Priargunskoe Industrial Mining and Chemical Union (Krasnokamensk, Russia):

Litvinenko V. G., Chief Technologist, Dr. Eng.
Sheludchenko V. G., Deputy Head of Central Scientific-Research Laboratory, Cand. Eng.
Morozov A. A., Head of Geotechnological Laboratory, Cand. Eng., phone : +7 (30245) 3-31-59

The deposits of Streltsovskoe ore field is presented mainly by the following enclosing rocks - rachidacite, andesite-basalt, granite, turfogravelite, cjglomerate and felsite. Rocks of all types with different relationship are forwarded to heap leaching, therefore acceptable metal extraction is achieved.
At present time, ores from upper levels in operating deposits of Streltsovskoe ore field are spent, and heap leaching is supplied with raw materials with essential part of dense rocks. Ores in these rocks are mainly disseminated, vein-disseminated, with high content of low-oxidized and refractory uranium minerals.
In order to examine in details technological parameters of heap leaching, technological prperties of spending uranium-bearing ores of several grades have been studied in laboratorial conditions. The results of investigations of percolation uranium leaching from crushed rock ores, presented by different enclosing rocks, are presented. Obtained geotechnological parameters are analyzed; they made the base for recommendations about restriction of granite charging in the scheme of depleted raw material processing. It was also recommended, in the process of determination of specific consumption of reagents and choice of the main parameters of percolation process in industrial conditions, to state duration of material processing and amount of metal extraction taking into account relationship between uranium enclosing rocks.