Author:
Name & Surname: Lavrov A. Yu.
Company: Transbaikal State University (Chita, Russia)
Work Position: Dean, Faculty of Economics and Management
Scientific Degree: Candidate of Engineering Sciences
Contacts: lavrov_2012@mail.ru

Besides the known forms of gold, reserves of which are being depleted, increasing emphasis is placed on micron, submicron and dispersed gold. Bulk of dispersed gold occurs between lattice points of minerals–concentrators. These can be either separate atoms or clusters of gold. In this case, gold recovery is possible through leaching of atoms making up the mineral. The active forms of oxygen, first and foremost, ozone, were proposed to be used to activate oxidation of sulfides containing gold by Corresponding Member of the USSR Academy of Sciences I. N. Plaksin as early as the 1940s. Somewhat afterwards, this area of research engaged scientists in America and Japan. In recent years, the similar studies are under way at the Moscow State University and the National University of Science and Technology. The most active forms of oxygen and their effect on oxidation were investigated by W. P. Van Antverp and Ph. A. Lincoln. The researchers found that oxidation is influenced not by ozone only but, to a great extent, by hydroxyl radical OHº (its redox potential reaches 2.3 V solely giving way to F). Treatment of water-air emulsion by ultra-violet creates active types of oxygen — O, O₃, H₂O₂, OHº etc — inside bubbles with pure oxygen or bubbles with mix of gases (O₂+ H₂). A time-phased large-scale experiment was carried out in Aprelkovo Mine, NordGold, in April 2014 — April, 2015. The longest phase trial, with maximum feed of percolators with ore pelletized in active solutions, and with recirculation of leaching solutions showed that increment of recovery was 20.5% in the proposed process flow diagram as against the process chart currently in use in the Mine, and was higher by 7.5% than in the process flow diagram with peroxide used as an oxidizer. Photoelectrochemical activation of working solutions and liquid phase of ore pulp ensures, owing to highly active oxidizers being formed, considerable rise in recovery of dispersed gold from ore and mine waste using both heap and agitation leaching circuits. This allows recommending the proposed technology as early as the given stage of development for commercial introduction in gold mines in Transbaikalia and Russian Far East.

1. Sekisov A. G., Trubachev A. I., Salikhov V. S., Lavrov A. Yu., Manzyrev D. V., Yurchenko Yu. S. Geologo-tekhnologicheskaya otsenka i novye geotekhnologii osvoeniya prirodnogo i tekhnogennogo zolotosoderzhashchego syrya Vostochnogo Zabaykalya (Geological-technological assessment and new geotechnologies of mastering of natural and anthropogenic gold-bearing raw materials of Eastern Zapolyarye). Chita : Transbaikal State University, 2011. 312 p.
2. Sekisov A. G., Shevchenko Yu. S., Manzyrev D. V., Petukhov A. A., Konereva T. G. Geotekhgologii izvlecheniya dispersnogo i «tonkogo» zolota iz tekhnogennykh mineralnykh obrazovaniy Zabaykalskogo kraya (Geotechnologies of disperse and “fine” gold extraction from anthropogenic mineral formations of Zabaykalsky Krai). Kulaginskie chteniya : materialy XI Mezhdunarodnoy nauchno-prakticheskoy konferentsii (Kulagin readings : materials of the XI International scientific-practical conference). 2011.
3. Plaksin I. N. Metallurgiya blagorodnykh metallov (Metallurgy of noble metals). Moscow : Metallurgizdat, 1958. 367 p.
4. Yannopoulos J. C. The extractive metallurgy of gold. Van Nostrand Reinhold Co : New York, 1991.
5. Lunin V. V., Popovich M. P., Tkachenko S. N. Fizicheskaya khimiya ozona (Physical chemistry of ozone). Moscow : Moscow State University, 1998. 480 p.
6. Krylova L. N. Fiziko-khimicheskie osnovy kombinirovannoy tekhnologii pererabotki smeshannykh mednykh rud Udokanskogo mestorozhdeniya : avtoreferat dissertatsii ... kandidata tekhnicheskikh nauk (Physical-chemical basis of combined processing technology of mixed copper ores of Udokan deposit : thesis of inauguration of Dissertation … of Candidate of Engineering Sciences). Moscow : MISiS, 2008. 195 p.
7. Van Antverp, Ph Lincoln. Precious metal recovery using ozone. Patent 4752412 USA. Filed: 12.07.85.
8. Shumilova L. V. Kombinirovannye metody kyuvetnogo i kuchnogo vyshchelachivaniya upornogo zolotosoderzhashchego syrya na osnove napravlennykh fotoelektrokhimicheskikh vozdeystviy : avtoreferat dissertatsii ... kandidata tekhnicheskikh nauk (Combined methods of cuvet and heap leaching of refractory gold-bearing raw materials on the basis of directed photoelectrochemical effects : thesis of inauguration of Dissertation … of Candidate of Engineering Sciences). Chita : Transbaikal State University, 2010.
9. Lavrov A. Yu. Effektivnost fotoelektrokhimicheskikh metodov vyshchelachivaniya zolota i molibdena iz tekhnogennykh mineralnykh obrazovaniy Zabaykalya (Efficiency of photoelectrochemical methods of gold and molybdenium leaching from anthropogenic mineral formations of Transbaikal region). Vestnik Zabaikalskogo Gosudarstvennogo Universiteta = Bulletin of Transbaikal State University. 2013. No. 5 (96). pp. 11–14.
10. Sekisov A. G., Rubtsov Yu. I., Lavrov A. Yu., Manzyrev D. V. Kuchnoe i kuchno-kyuvetnoe vyshchelachivanie zolota s ispolzovaniem fotoelektroaktivirovannykh rastvorov (Heap and heap-cuvet gold leaching using photoelectroactivated solutions). Zolotodobyvayushchaya promyshlennost = Gold mining industry. 2013. No. 1.
11. Sekisov A. G., Lankov B. Yu., Korolev V. S., Lavrov A. Yu., Grinchenko I. V. Perkolyatsionnoe vyshchelachivanie zolota fotoelektroaktivirovannymi rastvorami na rudnike «Aprelkovo» (Percolation gold leaching by photoelectroactivated Aprelkovo mine solutions). Zolotodobyvayushchaya promyshlennost = Gold mining industry. 2014. No. 5, 6.