“A qualified person has not done sufficient work to classify the historical estimate as current mineral resources, Stans Energy Corp. is not treating the historical estimate as current mineral resources and the historical estimate should not be relied upon.” Dr Gennady Savchenko QP for Stans Energy Corp., and managing Director for Stans Energy KG.
Rare earth metals (hereinafter REM) were known at the Aktyuz Ore Fields of the Kyrgyz Republic since the 1930s and started to be seriously examined from 1956, when industry was in sharp need for elements of yttrium group, especially thulium. By that time the geological service of the Republic had general information about rare earth metals thanks to research by N.D. Tikhomirov (1947), E.E. Korostylyova (1946), S.D. Turovsky (1947) and others.
Prospecting of the big rare earth deposit, Kutessay II, started in 1956 and was finished in 1959. Simultaneous prospecting was conducted within Aktyuz ore field, Talas region, Baybichen-Saur malms, Kastek mountain ridge and other areas. As a result of this work, evaluations were completed on these areas for REM. Reserves of REM for the Kutessay II deposit were approved by the State Reserve Committee [GKZ] of the USSR (N.I. Doroshenko and others, 1959).
Later interest in REM was restricted to the Kutessay II deposit. Specialized research for other types of rare earths was discontinued. New discoveries of rare earths were discovered only incidentally, by the geological survey on a scale 1:50000-1:25000 while searching for other metals.
Production of REM in the USSR was fulfilled thanks to the development of three deposits: Kutessay II (the Kyrgyz Republic) with significantly scarce yttrosynchysite –xenotime ores; Melovoy uranium-rare earth (Kazakhstan) with REM of mainly yttrium group (in a small volume); Lovozero rare earth-niobium-tantalum (Murmanskaya Oblast), concentrates of which contained REM of the less scarce ceric group.
Mining of Kutessay II was suspended and temporarily closed down at the beginning of 1995, and the volume of mining at Melovoy deposit by that time sharply decreased. Levozersky was closed in 2001.
State balance of mineral reserves of the Kyrgyz Republic considers REM reserves only in one deposit - Kutessay II (Fig. 1, 2).
Kutessay II Rare Earth Deposit The Kutessay II deposit is located in Kemin Region of Chu Oblast, 43 km by paved road from the Bystrovka railway station. The deposit is one of three pipe-shaped (Kutessay I, Kutessay II and Kutessay III) granophyric ore bodies of upper Permian age intruding green shale of upper Proterozoic age at a depth of about 150 m and individual stocks are united into a single body presenting a peculiar satellite of Malokeminskaya crack of intrusion of leucocratic subalkaline granite.
Ores are mainly complex: REM, zirconium, thorium, lead, zinc, silver, bismuth, molybdenum. Main rare-earth minerals: monazite, xenotime, yttrobastnaesite, yttroparasite, yttrosynchysite, yttrofluorite, fluocerite, cyrtolite, ferritorite, malacon. The deposit has a peculiar zoning of mineralization distribution: in the upper part of granophyric stocks it is polymetallic and rare earth, in the middle part rare earth, and in the lower part zirconium-thorium-rare earth mineralization.
At the Kutessay II deposit, there are the following 8 types of rare-earth ores (quartz-chlorite, quartz-sericitic, hysgine granophyric, quartz-muscovite, egovite, brecciation shale, silex metasomatite, and crystal ores of secondary quartzites).
First three types form 80% of all REM reserves and have high indices of recovery (extraction of REM from ore averaged 64.5% and the metal content of 6.2% in a concentrate can be improved).
Fig.1. Geological map of the Aktyuz ore feld.
1 – Quaternary sediments; 2 – Middle Paleozoic rhyolite; Precambrian metamorphic rocks: 3 – schist and amphibolite of Paleoproterozoic Kuperlisai Formation; 4 – gneiss of Archean Aktyuz Formation; Permian-Triassic intrusive rocks: 5 – granophire; 6 – subalkali leucogranite of the Kuperlisai pluton; 7 – syenite; Middle Paleozoic intrusive rocks: 8 – diorite and quartz diorite; 9 – granodiorite and granite; Precambrian metabasic rocks: 10 – amphibolite and gabbro-amphibolite; 11 – metagabbro and metadiabase; 12 – postmineral quartz lenses; 13 – faults; 14 – section line. Major faults (letters on the map): (A) West Kuperlisai, (B) East Kuperlisai, (C) Kutessai, (D) Cholonsai, (E) Anjilga, (G) Aktyuz-Karabatnak, (L) Rudny, (K) Kvartsevy, (M) Yuzhny, (N) Sienitovy. Ore deposits and prospects (numerals on the map): (I) Kutessai-I, (II) Kutessai-II, (III) Kutessai-III, (IV) Kuperlisai, (V) Kolesai, (VI) Aktyuz, (VII) Kemin mineralization zone.
Fig.2. Schematic map and sectional views of Kutessay II deposit
In 1958 exploration at the deposit was completed and on 01.01.1959 REM reserves were calculated and approved by GKZ (table 1).
Table 1
Historical Reserves of REM approved by State Reserve Committee [GKZ] of the USSR on 01.01.59
(See Footnotes 1 and 2)
Relative share of individual rare-earth elements in total REM at Kutessay II deposit (according to 300 X-ray spectrum analyses) is shown in Table 2.
Table 2
Relative Historical Quantity of Individual Rare Earth Elements in Kutessay II Ores
(See Footnote 1)
By the time exploration at Kutessay II deposit was completed, there were the following competitive REM deposits in the Ukraine and Russia (Table 3).
Table 3
Information about Historical Soviet REM deposits
(See Footnotes 1 and 2)
Taking into consideration ore reserves, the significant elements of yttrium group (47.16%) and availability of the existing ore mining and processing plant (Aktyuz mine) the decision was made to develop the Kutessay II deposit. From 1958 onward, the Kyrgyz Mining and Smelting Enterprise (KGMK) was the most powerful in the country and it included the Kutessay II open pit, concentrating mill and chemical-metallurgical plants. Until 1990 the enterprise met 80% of the requirements of the former USSR in yttrium and other REM compounds.
Before 1995 the Kyrgyz Chemical and Metallurgical plant produced 120 rare-earth products including oxides of yttrium group, luminophor К-77, К-84, oxides of lanthanum, neodymium, cerium dioxide, and pure (99.99) RE metals and alloys.
In 1974-83 Aktyuz ore enterprise conducted supplementary exploration of deep levels (below 2353 m horizon) at Kutessay II deposit. Earlier explored reserves of REM ore of category C were converted to category B, A. The reserves calculation report was approved by The State Reserve Committee [TKZ] of the Kyrgyz Republic in 1995 (Protocol No 445, 1995).
During exploitation of the Kutessay II deposit (1958-91) 5,454,400 tones (t) of ore were mined producing 22,109 t. of REO (content in ore – 0.41%), 145,000.t. of ore containing 3300 t. of REM were written off and 1,885,000 t. of ore containing 4870 t. of REM were transferred from balance to below cutoff grade. Taking into consideration the above mentioned changes and additional exploration of Kutessay II deposit, the state of reserves as of 01.01.1996 (a date of temporary closing-down of the mine) is shown in Table 4.
Table 4
Historical Reserves of REM approved by the State Reserve Committee of the Kyrgyz Republic TKZ at the Kutessay II deposit on 01.01.1996
(See Footnotes 1, 2 and 3)
In accordance with the Decree of the Government of the Kyrgyz Republic (No 16 of 01.05.95) mining operations at Kutessay II deposit were shut down temporarily.
Footnote 1: “A qualified person has not done sufficient work to classify the historical estimate as current mineral resources, Stans Energy Corp. is not treating the historical estimate as current mineral resources and the historical estimate should not be relied upon.” Dr Gennady Savchenko QP for Stans Energy Corp., and managing Director for Stans Energy KG.
Footnote 2: The title ‘Reserves’ is a direct translation. No official reserve calculation has been completed by Stans Energy Corp.
Footnote 3: The summing of Soviet Reserve Categories B, C1, and C2 do not comply with NI 43-101 rules, and should not be relied on.
