Laboratory of Nature-like Technologies and Technosphere Safety of the Arctic

We walk around the Khibiny and Lovozero and look for new minerals, and then we study them. Sometimes we find them, and then it turns out that they have unique properties =)

For the first time, the possibility of using thermally activated serpentine materials (chrysotile and lizardite), which are waste products of the mining industry, as additives for remediation of soils with extreme multi-element contamination with potentially toxic metals, has been investigated. It has been shown that thermally activated serpentine is effective for the sorption of copper and nickel from sulfate solutions, while the hydration of the mineral does not significantly affect the chemical stability of the components and its sorption properties. In a ten-year field experiment in the impact zone of an operating non-ferrous metallurgy enterprise located in the Subarctic region of the Russian Federation, the effectiveness of materials for reducing the amount of mobile fractions and increasing the proportion of strongly bound fractions of potentially toxic metals, as well as the reclamation effect of soil enrichment with calcium and magnesium, was shown. The grass communities formed in the long-term experience have shown high productivity and stability in the conditions of ongoing aerotechnogenic pollution. Thermally activated serpentine minerals can be recommended for the rehabilitation of landscapes with lost vegetation and high levels of contamination with potentially toxic metals.

During the development of deposits, most of the precious metals are not extracted in any way. The presence in the Murmansk region of large deposits of various raw materials (loparite, ilmenite, perovskite, titanomagnetite and titanite) opens up great opportunities and prospects for the synthesis of various forms of ivanyukite, and, at the same time, a significant reduction in their cost due to the geographical availability of all other components and the absence of the need for their transportation. Ivanyukite is a promising sorbent for the reduction of platinum from a mixed solution of gold, platinum and palladium. In this case, platinum is released on the surface of sorbent particles in the form of nanometer–sized balls, and gold is released in the form of lamellar micro-nanocrystals. The preparation of this sorbent is carried out using the technology developed and patented by the Kola Scientific Center for the direct processing of titanite ores into salt STA (ASOT). Due to this, the use of local raw materials allows you to reduce the cost of 1 kg of sorbent from 24,829 rubles to 3,000 rubles. The next stage of the project is the design of a filter unit with a sorbent that will not disrupt the technological scheme of production. Promising consumers of sorbents and the proposed purification technology are industrial enterprises for the production of copper and nickel (primarily in the territory of the Russian Federation, KGMK Severonikel).

The accumulation of radioactive waste at nuclear power plants and the military-industrial complex is a global problem of civilization, fraught with catastrophes of a regional and universal scale. The methods of immobilization of radionuclides used in all countries through bitumen, cementing or vitrification of LRW, in fact, are a temporary measure that does not guarantee reliable fixation of radionuclides in the composition of the corresponding matrices [1-4]. A more reliable and relatively cheap method of preserving radioisotopes is their localization in the composition of halogenides and (halo)phosphates crystallizing at room temperature, such as strontium fluorite SrF2 or monazite (EuAc*)PÜ4 [5,6]. Here, unlike cements and single-phase glasses (borosilicate, aluminosilicate and phosphate glasses), radionuclides are included in the crystal structure of these compounds. However, the relatively low solubility of phosphates and halides, especially in acidic or alkaline environments, as well as their weak resistance to self-radiation, do not completely solve the problem of immobilization of radionuclides in their composition. The most "long-lived" and safe for possible natural effects (flooding, earthquakes, etc.) are mineral-like ceramic matrices consisting of chemically and mechanically stable phases capable of storing a sufficiently large amount of radionuclides for a long time (hundreds to thousands of years) without significantly changing their crystal structure or, at least, chemical connectivity the resulting amorphous phases, as a result of self-radiation. These minerals include, first of all, various titanates and zirconates (zirconosilicates): rutile (Ti, Ac*, Tc)Ü2, tausonite SrTiÜ3, pyrochlore (Cs, Ac*, Eu)2TÍ2Ü7, Hollandite Csi-x(Ti, Ac*, Tc)sÜi6, tageronite (Zr, Ac*, Tc)Ü2, zirconite Sr(Zr, Ac*)TÍ2Ü7, zircon (Zr, Ac*, Tc)SiÜ4, etc. [1-3,5,7]. In this regard, until recently, the most promising technology was the immobilization of radionuclides in the composition of Synroc (synthetic rock or "synthetic rock") mineral-like ceramics of the Australian Organization for Nuclear Research and Technology ANSTO, for which the LRW after concentration is mixed with a titanate charge and calcined at temperatures of the order of 1000-1500 ° C [2,5]. Typical Synrock ceramics consist of zirconolite, perovskite, hollandite and various alloys. However, this complex and energy-consuming technology has not been widely used, so the development of new, more efficient and cheaper technologies for the sorption of radionuclides from LRW and their further immobilization as part of stable mineral-like matrices is an urgent task.