Determination of the content of rare metals in spent anion-exchange resin SIM202 by methods of neutron-activation and mass-spectrometric analysis

The work is devoted to the development of methods for determining the elemental and isotopic composition of spent ion-exchange resin, industrial waste and environmental objects using an inductively coupled plasma mass spectrometer and analyzing specific samples to determine the content of noble and rare metals in technological materials, industrial waste and natural objects with application of the developed techniques. This article determines the elemental composition of the spent ion-exchange resin SIM202 with the Inductively coupled plasma mass spectrometry (ICP-MS) method and also shows the comparison of the results with neutron activation analysis (NAA). The distribution coefficient of elements in a chromatographic column in ion-exchange resins TAO and SIM202 is given.

Radioecological Assessment of Uranium Tails Deposits (Sumsar, Shekaftar, Terek-Sai)

The article presents the results of radio ecological studies of the territories of uranium tailings in Kyrgyzstan (Sumsar, Shekaftar and Terek-Sai), as well as their current state and assessment of the radioactive contamination’s potential risks. The ore field of this region is characterized as an extremely complex structure and covers about 30 ore occurrences of lead and rare metals. Starting from the Precambrian period both applicative and disjunctive disturbances within its boundaries have been widely developing and being manifested many times throughout the history of geological development. Oxidized and sulfide ores have been developed within the deposit. Unfortunately, serious miscalculations were made. As result of natural disasters; such as earthquakes, landslides, mudflows, etc., several uranium tailing dumbs have been damaged. Day by day, the risk of destruction and the threat of radioactive contamination of the Kyrgyz Republic territory are increasing. There are eight tailing dumps on the territory of Shekaftar uranium natural-technogenic province, the total volume of which is 1194 thousand m3 of radioactive waste. There are 15 mountain dumps of substandard ore with an ore volume of 4585.6 thousand m3. Hour, in local areas it exceeds 500 μR/h.

The Research of Iron Containing Wastes Modification Process of Leninabad Rare Metals Plant

The paper presents the results of ferriferous wastes modification process research carried on the basis of JCS “Leninobad rare metals Plant” located in the Republic of Tajikistan. The wastes for the study were taken from the western tailing. The article presents the justification of the chosen wastes as a filling material in the development of new radiation protective composite building materials. The data on the initial ferriferous chemical composition of the tailing wastes and the chemical composition of the material that passed the enrichment process is presented. The study contains microphotos of ferriferous haematite raw material particles surface before and after completing the modifying process. The paper presents and describes the study of X-ray phase analysis diffractograms of enriched iron-containing wastes before and after the modification process. The current research proves that the enrichment ferriferous wastes particles modification process is possible and as a result it can be used as a filling for the development of new kinds of radioprotective composite materials.

A review of indium recycling methods from LCD screen wastes

Indium, one of the important rare metals, has drawn more and more attention due to its semiconductor and optoelectronic performance. The by-products of zinc refineries are used as the primary mineral resources for the commercial production of indium. Indium contents of these products usually vary in a range of 100÷200 g/t. However, as a main secondary source of indium, LCDs waste contains much higher contents of indium than that in mineral ores. LCDs waste may contain up to 1,400 g/t In (equivalent to 0.7 g/m2). The indium recovery process from LCD screen wastes undergoes three stages: dismantling LCD screens; separation of indium-containing ITO glass, and recovery of indium metal. This paper presents the characteristics of the indium recovery process from LCD screen wastes and the main techniques used in each stage of technology. From there, a few suitable specific indium recycling processes are proposed for the conditions in Vietnam.

LOW- GRADE STRUCTURES OF NOBLE AND NON- FERROUS METALS AND METHODS OF THEIR SELECTIVE SEPARATION

There is a worldwide trend of increasing the share of extraction and processing of low-grade minerals, but their extraction and processing volumes are still low. There are several reasons for this: high mining and transportation costs, imperfect techniques and technological difficulties in enrichment and processing of refractory and low-quality minerals. Due to the depletion of reserves of easily beneficiated raw materials and to compensate for the growing shortage of high-quality minerals, the Russian mining industry development strategy provides for the involvement of new and unconventional types of deposits into production. Examples of such deposits are deposits of carbonaceous raw materials (black shale, refractory sulphide carbon-bearing ores, impactites, etc.) containing carbon of varying degrees of metamorphism. On the basis of the most modern mineralogical, physical, nuclear and chemical methods of research of composition, structure and properties of the carbonaceous raw materials at the micro- and nanolevel, the composition of the productive mineral matter, physical, chemical and thermodynamic laws of separation of valuable mineral components and the basic technological processes to obtain the finished product for valorization of the unconventional carbonaceous mineral raw materials were determined with maximum reliability. One of the possible reasons of difficulty of beneficiation of carbonaceous raw materials is the fine phenocrysts in graphite which can be solved by using the flotation process. Contrast of surface properties of minerals with similar technological properties can be increased by application of different energy effects (MEMI, MIO, microwave, electrochemical treatment etc.) at successive stages of raw material transformation, regulation of pulp conditioning conditions (duration and intensity of agitation, heat treatment of pulp) as well as by development and application of selective reagent regimes. The special feature of flotation as a method of extraction of noble and rare metals is the ability to extract valuable metals not only in their native free form, but also in close association with sulphides and carbon. Flotation with the use of intensifying influences made it possible to transfereven low-sized structures of noble and rare metals, which are not extracted by conventional methods of cyanidation, gravitation enrichment and amalgamation, into the concentrate. One of the ways to increase the efficiency of the flotation process is preliminary modification of the additive which is introduced in addition to the main reagents of the sinter - “carrier material”.

Genesis of the Bieyesamas Monzogranite of the Altay Mountain, Xinjiang, Northwestern China, and Its Rare Metal Resource Potential

Lying in the Altay Orogenic Belt in Xinjiang, Northwestern China, the Bieyesamas monzogranite pluton is located in the North Altay Terrane. It is one of the important granitic batholiths with a large amount of rare metal pegmatite dikes. According to LA-ICP-MS zircon U-Pb isotopic dating, the 206Pb/238U weighted average age of the Bieyesamas monzogranite is 451.1 ± 5.1 Ma ( MSWD = 6.0 ), indicating the formation age of Late Ordovician. The Bieyesamas monzogranite has secondary minerals such as garnet and tourmaline. The geochemical analysis shows that the pluton is characterized by high SiO2 (70.45%~75.44%), Al2O3 (14. 04%~17.14%), potassium and alkaline ( K 2 O = 4.20 % ~ 4.78 % , N a 2 O + K 2 O = 7.90 % ~ 8.99 % ), A/CNK (1.16~1.28), and high corundum (2.33%~5.08%) being found in CIPW standard minerals, belonging to high-K calc-alkaline peraluminous series. The pluton is enriched in LREE, depleted in HREE ( LREE / HREE = 5.99 ~ 9.65 ), with obviously negative Eu anomaly ( δ Eu = 0.44 ~ 0.60 ), while the trace elements are characterized by Rb, K, Nb, Ta, Hf, and U enrichment and Ba, Sr, Ti, and Zr depletion, as well as with high differentiation index ( DI = 93.24 % ). Zircon ε Hf t values range from 2.89 to 7.69, with the corresponding two-stage model ages ( T DM 2 ) of 941~1257 Ma. The mineral assemblage, geochemical characteristics, and zircon Hf isotope indicate the pluton experienced the highly fractionated process and belongs to highly fractionated S-type granite, which was formed by partial melting of the Meso- to Neoproterozoic crustal material. In the Bieyesamas monzogranite, the average contents of rare metals are obviously higher ( Li = 550 × 10 − 6 , Be = 10.18 × 10 − 6 , Nb = 18.91 × 10 − 6 , Ta = 2.14 × 10 − 6 , Rb = 500 × 10 − 6 , and Cs = 149.9 × 10 − 6 ) than the other rocks and Clark values of crust, which indicates that the Bieyesamas pluton has the enrichment potential of rare metals. The metallogenic geological conditions are superior in the Bieyesamas area of the Altay Mountain, and rare metal deposits and ore spots are widely distributed. In particular, the newly discovered rare metal deposits are characterized by large-scale mineralization, high grade and industrial utilization value, etc. It is preliminarily predicted that they have reached the medium-scale deposits. Therefore, the Bieyesamas area is one of the key areas for rare metal prospecting breakthroughs in the future, with great potential for rare metal mineral resources.