In accordance with the Decree of the President of the Republic of Uzbekistan dated January 17, 2019 “On measures to further improve the activities of enterprises in the mining and metallurgical industry”, the plant is implementing major projects to classify reserves in accordance with international standards of the JORC Code.
In connection with introduction of the new world standards in Uzbekistan in all areas of the economy of the Republic, innovations have not left out the mining and metallurgical industry. Among the first who started to implement them, is JSC “Almalyk MMC”. The staff of many departments of the plant participate in their implementation. It is no exaggeration to say that one of the leading roles is played by geologists.
One of the main tasks is to expand and re-evaluate the ore reserves of the deposits developed by the plant. Currently, AMMC is mining and geologically exploring about 20 ore deposits located in four regions of the Republic. These are deposits in the Tashkent region: gold and copper – "Oliy Ziyo" (sections "Kalmakyr", "Yoshlik I"), copper – "Sary-Cheku", gold-silver – "Kyzyl Alma", "Kochbulak", "Kairagach", "Kauldy"; in the Namangan region, gold-silver – "Pirmirab", "Guzaksay"; in the Surkhandarya region, polymetallic – "Khandiza"; in the Jizzakh region – "Balyklitau" (for the needs of the cement plant).
On the pages of the newspaper "For non-ferrous metals" we have already said that for all the ore deposits of the plant, the reserves are recalculated according to the accepted world standards of the Code of Reporting on Exploration Results, Mineral Resources and Ore Reserves (JORC Code). This Code establishes the standards, recommendations and principles for the use of public reporting on exploration results, mineral resources and ore reserves. Calculation of reserves according to the JORC Code presents understanding of the situation regarding the possibility of commercial development of a deposit and making decisions on the feasibility of development, determining the level of reliability in assessing its geological resources and reserves. In this case, the principles of deposit evaluation are used, which involve collection and evaluation of geological data, determination of the geometry of ore body, calculation of resources and reserves suitable for extraction, with simultaneous verification of the reliability of data obtained.
Since the beginning of 2019, JSC “Almalyk MMC” has been cooperating with one of the most reputable companies in the world in this area, SRK Consulting (Great Britain), with which it is implementing three projects – Almalyk, Angren, and Handiza. The Almalyk project provided for work on the re-evaluation of the reserves of the “Oliy Ziyo” field.
During this time, a great work has been done to bring the reserves in accordance with the international classification of the JORC Code and their growth in these fields. For more than two years, the analysis has been carried out, ranging from historical geological data to the present day. And this is about a hundred years: from the 30s of the last century to the present. 2008 so-called historical wells were analyzed, and this is more than 667 thousand running meters. Since 2019, more than 470 new boreholes, or more than 206 thousand running meters, have been drilled here, about 114 thousand samples have been taken, and analyzes have been carried out in independent international laboratories that meet modern world standards. The results of the drilling program were successful and confirmed that the Kalmakyr and Yoshlik I sites are one of the largest copper-gold deposits in the world and there is a potential for finding additional industrial mineralization at deep horizons and, possibly, in new areas.
We can say that during this time the reserves and resources of these deposits were re-examined and included in the list of the largest ore deposits in the world. According to statistics, Oliy Ziyo currently ranks third in terms of available ore resources, sixth in terms of copper in ore, and first in terms of gold in ore among copper deposits.
To date, together with the international company SRK Consulting, a report has been compiled in which the reserves of the Oliy Ziyo field have been calculated in accordance with the classification of the international JORC Code, which was first considered by the State Commission on Reserves of the Republic of Uzbekistan.
Hydrogeological and geotechnical studies of the level of the international feasibility study were also carried out.
In order to determine the stability of the sides of the open pits of the Oliy Ziyo field, determine the slope angles with the most accurate calculations, water inflow and create a geomechanical and hydrogeological model of the combined open pit, hydrogeological and geotechnical surveys were carried out by drilling 56 wells in the volume of 17995 linear meters.
As part of the field research program, the following tasks were completed: drilling, testing and installation of 16 hydrogeological wells: 4 open-ended piezometers and 12 vibrating string piezometers (VSP); testing in 22 geotechnical wells and installing VSP in two of them; in geotechnical wells, complex packer tests, flow metering and experimental pumping were carried out; measuring the flow of local watercourses near the quarry; installation and testing of artesian wells; water sampling and sending to the laboratory for chemical analysis.
To create a geotechnical model, geological, structural, hydro-geological models, as well as a model of secondary changes were used.
Laboratory data of geotechnical wells includes about 5400 different tests (for uni- and triaxial compression, rupture, multi-stage tests of natural fractures for direct shear, point load tests to form a database of properties of intact rocks, exposed lithologies).
Slope stability was analyzed on 19 cross sections using updated contours of the final (100 years) and intermediate (30 years) positions of the open pit.
In continuation of exploration work, the next stage of work is planned this year to study deep horizons and reclassify mineral resources to higher categories in accordance with the classification of the JORC Code.
Deputy Head of the Geological Department for Open Mining of JSC “Almalyk MMC”