I. V. Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials of the Kola Science Center of Russian Academy of Sciences, Apatity, Murmansk Oblast, Russia:
N. S. Areshina, Senior Researcher, e-mail: areshina@chemy.kolasc.net.ru
A. G. Kasikov, Head of a Sector of Hydrometallurgy of Cobalt, Nickel and Noble Metals
A. M. Petrova, Senior Researcher
E. S. Kshumaneva, Researcher

We studied the ruthenium recovery from multicomponent solutions of heatresistant nickel alloys waste processing by distillation method. Model sulphuric acid solutions were used to demonstrate the efficiency of oxidizing agents containing Cr (VI) or Co (III). Studies were made of the kinetics of ruthenium distillation from solutions produced by processing the heat-resistant nickel alloys waste. In order to oxidize ruthenium in chloride it was suggested to fulfill preliminary sulphuric acid treatment with the view of stable chloride complexes conversion into sulphate and sulphate-chloride ones. Optimal distillation parameters were determined when the level of ruthenium extraction into 6 mole/l HCl absorbing solution was 85–99%. The saturated solution was then evaporated and hydrolytic precipitation was applied to obtain the hydrated ruthenium oxide. The flowsheet was proposed of processing the multicomponent rutheniumcontaining sulphate, chloride and sulphate-chloride solutions. In case of necessity to convert the chloride complexes the flowsheet provides for preliminary sulphuric acid treatment of solutions. The solution containing 3–5 mole/l H₂SO₄ is fed for ruthenium distillation using potassium bichromate or cobalt-containing hydrate product as oxidant. The oxidizer choice depends on the initial solution composition as well as the possibility of reprocessing the distillation vat residue. It is more preferable to use the Co (III) based oxidizer because of its process stability due to gradual dissolution in sulphuric acid and smaller toxicity. The RuO₄ is absorbed from the gas phase by hydrochloric acid solution whereof the hydrated ruthenium oxide applicable for pure metal production is precipitated. Taking into account high selectivity, the offered ruthenium distillation technique is applicable for ruthenium recovery from various sulfate, sulfate-chloride or chloride solutions irrespective of the kind of source material. The investigations were carried out with the partial support of the Program of Fundamental Investigations of the Department of Chemistry and Materials Science RAS (Program No. 5 “Creation of new types of products from mineral and organic raw materials”).

1. Sankuviruthiyil M. Ujwaldev, Kallikkakam S. Sindhu, Amrutha P. Thankachan, Gopinathan Anilkumar. Recent advances in aerobic oxidation with ruthenium catalysts. Tetrahedron Letters. 2016. Vol. 57, No. 50. pp. 5551–5559.
2. Sankuviruthiyil M. Ujwaldev, Kallikkakam S. Sindhu, Amrutha P. Thankachan, Gopinathan Anilkumar. Recent developments and perspectives in the ruthenium-catalyzed olefin epoxidation. Tetrahedron. 2016. Vol. 72, No. 41. pp. 6175–6190.
3. Wenbo Shi, Xiaolong Liu, Junlin Zeng, Jian Wang, Yaodong Wei, Tingyu Zhu. Gas-solid catalytic reactions over ruthenium-based catalysts. Chinese Journal of Catalysis. 2016. Vol. 37, No. 8. pp. 1181–1192.
4. Heon Jae Jeong, Jun Woo Kim, Dong Young Jang, Joon Hyung Shim. Atomic layer deposition of ruthenium surface-coating on porous platinum catalysts for high-performance direct ethanol solid oxide fuel cells. Journal of Power Sources. 2015. Vol. 291. pp. 239–245.
5. Gregorczyk K., Banerjee P., Rubloff G. W. Conduction in ultrathin ruthenium electrodes prepared by atomic layer deposition. Materials Letters. 2012. Vol. 73. pp. 43–46.
6. Vougioukalakis G. C., Philippopoulos A. I., Stergiopoulos T., Falaras P. Contributions to the development of ruthenium-based sensitizers for dye-sensitized solar cells. Coordination Chemistry Reviews. 2011. Vol. 255, No. 21–22. pp. 2602–2621.
7. Kasikov A. G., Petrova A. M. Rhenium recycling. Moscow : RIOR ; Infra-M, 2014. 95 p.
8. Ginzburg S. I., Ezerskaya N. A., Prokofeva I. V., Fedorenko N. V., Shlenskaya V. I., Belskiy N. K. Analytical chemistry of platinum metals. Moscow : Nauka, 1972. 403 p.
9. Livingston S. Chemistry of ruthenium, rhodium, palladium, osmium, iridium and platinum. Moscow : Mir, 1978. 366 p.
10. Analytical chemistry of platinum group metals: Collection of review articles. Yu. A. Zolotov, G. M. Varshal, V. M. Ivanov. Second edition. Moscow : KomKniga, 2005. 592 p.
11. F. E. Beamish. Analytical chemistry of noble metals. In two volumes. Volume 1. Moscow : Mir, 1969. 297 p.
12. Chi V. Ly, Hiroshi Hidaka. Determination of ruthenium contents in terrestrial minerals by isotope dilution mass spectrometry after preconcentration via distillation. Geochemical Journal. 2004. Vol. 38. pp. 485–490.
13. Balcerzak М., wicicka Е. Determination of ruthenium and osmium in each other's presence in chloride solutions by direct and third-order derivative spectrophotometry. Talanta. 1996. Vol. 43, No. 3. pp. 471–478.
14. Toshiyasu Kiba, Kikuo Terada, Tomoe Kiba, Kazuo Suzuki. Separation and determination of ruthenium by evolution with chromium(VI)-condensed phosphoric acid reagent. Talanta. 1972. Vol. 19, No. 4. pp. 451–464.
15. Kotlyar Yu. A., Meretukov M. A., Strizhko L. S. Noble metals metallurgy. In two volumes. Volume 2. Moscow : “Ore and Metals” Publishing House, 2005. 392 p.
16. Meyer H., Grehl M., Nowottny C., Stettner M., Kralik J. Processes for the recovery of ruthenium from materials containing ruthenium or ruthenium oxides or from ruthenium-containing noble metal ore concentrates. Patent US2011/0165041 (A1). Filed: 18.03.2011. Published: 07.07.2011.
17. Nagai H. Apparatus for removing ruthenium from solution containing platinum group metal. Patent US, No. 7938880. Filed: 04.02.2010. Published: 10.05.2011.
18. Meyer H., Grehl M., Alt H.-J., Patzelt P., von Eiff H., Zell B. Processes and devices for removing ruthenium as RuO₄ from ruthenate-containing solutions by distillation. Patent US2009/0191106 (A1). Filed: 23.01.2009. Published: 30.07.2009.
19. Shindo Y., Suzuki T. Process for producing high-purity ruthenium. Patent US, No. 6036741. Filed: 16.07.1998. Published: 14.03.2000.
20. F. E. Beamish. Analytical chemistry of noble metals. In two volumes. Volume 2. Moscow : Mir, 1969. 400 p.
21. Kasikov A. G., Areshina N. S., Gromov P. B., et al. Method of osmium extraction from ion-exchange resin. Patent RF, No. 2131939. Applied: 22.06.1998. Published: 20.06.1999. Bulletin No. 17.
22. Kasikov A. G., Areshina N. S., Gromov P. B., Khomchenko O. A., Ponomarev A. A. Extraction of osmium and silver from middlings and wastes of Severonikel Combine. Tsvetnye Metally. 2000. No. 10. pp. 19–22.
23. Basis of metallurgy. Volume 5. Small, noble and radioactive metals. Transuranium elements. Responsible editors: N. S. Greyver, N. P. Sazhin, I. A. Strigin, A. V. Troitskiy. Moscow : Metallurgiya, 1968. 630 p.
24. Ilyashevich V. D., Ryumin A. I., Mamonov S. N., Sidorenko Yu. A., Khodyukov B. P. Method of affined ruthenium obtaining. Patent RF, No. 2094501. Applied: 05.09.1995. Published: 27.10.1997.
25. Xu Chonging, Li Weimin, Cameron T. M. In situ generation of RuO₄ for ALD of Ru and Ru related materials. Patent US, No. 8663735. Filed: 13.02.2010. Published: 04.03.2014.