Institute Integrated Mineral Development—IPKON, RAS, Moscow, Russia:

V. A. Chanturia, Chief Researcher, Doctor of Engineering Sciences, Academician of the Russian Academy of Sciences, vchan@mail.ru
V. G. Minenko, Leading Researcher, Associate Professor, Candidate of Engineering Sciences

Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials, Kola Science Center, Russian Academy of Sciences, Apatity, Russia:
O. V. Suvorova, Senior Researcher, Candidate of Engineering Sciences

Institute of Industrial Ecology Problems of the North, Kola Science Center, Russian Academy of Sciences, Apatity, Russia:
D. V. Makarov, Head of Laboratory, Associate Professor, Doctor of Engineering Sciences

Using a package of modern methods of mineral substance analysis, the authors obtain scientific evidence on structural, physicochemical properties and mineral composition of products electrochemically removed from saponite-containing service water at Severalmaz diamond mines. It is found that microstructure of electrochemically modified saponite precipitation features large cellular texture with domination of roundish cells 3–5 μm in size, dense packing and small size pores, which increases specific surface area from 40 to 44 m²/g. The analysis of mineral composition of electrochemically modified saponite sample shows the increased concentration of montmorillonite group minerals from 68 to 74.5 % at the quartz and dolomite content reduced by 4 %. The studies of electrochemically modified saponite using the differential scanning calorimetry in the atmosphere of air and argon yields that:
• the basic mineral substance of the test samples is saponite Ca of Mg type with some few of montmorillonite;
• modified saponite-bearing product is characterized with the presence of iron atoms in the structure, higher total iron and more amount of structured water as compared with the initial sample, which indirectly confirms higher concentration of saponite.

Chemical composition of modified saponite-bearing product (SiO₂, Al₂O₃, CaO, Fe₂O₃, FeO, TiO₂, Na₂O, K₂O, SO₃ etc.), dense packing and higher concentration of montmorillonite group minerals meet the production standards of different construction materials. The use of electrochemically modified saponite to produce high-quality ceramic construction materials with the improved physico-mechanical properties and ornamental characteristics ensures higher compression and bending strengths (increased by 1.4–1.7 and 1.3–3.3 times, respectively) as compared with the products made of the initial untreated materials.
This study has been supported by the grant of the President of the Russian Federation for the government funding of leading schools in the Russian Federation: Academician Chanturia School Grant NSh-748.2014.5.

1. Gorkin A. P. Geography : modern illustrated encyclopedia. Moscow : Rosmen-Press, 2006. 624 p.
2. Gebretsadik F., Mance D., Baldus M., Salagre P., Cesteros Y. Microwave synthesis of delaminated acid saponites using quaternary ammonium salt or polymer as template. Study of pH influence. Applied Clay Science. 2015. Vol. 114. pp. 20–30.
3. Villa-Alfageme M., Hurtado S., Castro М. A., Said E., Alba M. D. Quantification and comparison of the reaction properties of FEBEX and MX-80 clays with saponite: Europium immobilisers under subcritical conditions. Applied Clay Science. 2014. Vol. 101. pp. 10–15.
4. Nityashree N., Gautam U. K., Rajamathi M. Synthesis and thermal decomposition of metal hydroxide intercalated saponite. Applied Clay Science. 2013. Vol. 87. pp. 163–169.
5. Wang W., Zhen W., Bian S., Xi X. Structure and properties of quaternary fulvic acid–intercalated saponite/poly (lactic acid) nanocomposites. Applied Clay Science. 2015. Vol. 109-110. pp. 136–142.
6. Çolak M., Helvac C., Maggetti M. Saponite from the Emet colemanite mines, Kutahya, Turkey. Clays and Clay Minerals. 2015. Vol. 48, No. 4. pp. 409–423.
7. Navrátilová Z., Maršálek R. Application of Electrochemistry for Studying Sorption Properties of Montmorillonite. Clay Minerals in Nature — Their Characterization, Modification and Application, September 2012. Chapter 14. pp. 273–294.
8. Saponit. Available at: http://www.saponit.ua/production-and-properties/glinu/ (accessed: 25.09.2016). (in Russian)
9. Osipov V. I., Sokolov V. N. Clays and their properties. Composition, structure and formation of properties. Moscow : GEOS, 2013. 575 p.

10. Minenko V. G. Justification and design of electrochemical recovery of saponite from recycled water. Fiziko-tekhnicheskie problemy razrabotki poleznykh iskopaemykh. 2014. No. 3. pp. 180–186.
11. Chanturiya V. A., Minenko V. G., Samusev A. L., Timofeev A. S., Ostrovskaya G. Kh. Electrochemical separation of OAO «Severalmaz» facilities saponite-containing tailings pulp. Obogashchenie Rud. 2014. No. 1. pp. 49–52.
12. Morozova M. V., Ayzenshtadt A. M., Makhova T. A. The Use of Saponite-Containing Material for Producing Frost-Resistant Concretes. Promyshlennoe i grazhdanskoe stroitelstvo. 2015. No. 1. pp. 28–31.
13. Morozova M. V., Ayzenshtadt A. M., Tutygin A. S. Water Absorption of Saponite-Containing Tails of Kimberlite Ore Dressing. Promyshlennoe i grazhdanskoe stroitelstvo. 2013. No. 11. pp. 29–31.
14. Oblitsov A. Yu., Rudalev V. A. Prospective ways of diamondiferous rock enrichment wastes utilization at M. V. Lomonosov diamond deposit. Zapiski Gornogo instituta. 2012. Vol. 195. pp. 163–167.
15. Suvorova O. V., Melkonyan R. G., Bokareva V. A., Makarov D. V., Belyaevskiy A. T., Pletneva V. E. Exploring the possibility of producing building ceramic from mining wastes. Tekhnika i tekhnologiya silikatov. 2012. Vol. 19, No. 2. pp. 19–25.