I. N. Ulyanov Chuvash State University (Cheboksary, Russia):

I. E. Illarionov, Dr. Eng., Prof, Head of the Chair “Materials science and metallurgical processes”, E-mail: tmilp@rambler.ru

I. N. Strelnikov, Cand. Eng., Associate Prof.

Chuvash Agricultural Academy (Cheboksary, Russia):
L. Sh. Pestryaeva, Cand. Ped., Associate Prof.

“ELKON” JSC (Cheboksary, Russia):
Sh. V. Sadetdinov, Dr. Chem., Prof., Chief Technologist, E-mail: avgustaf@list.ru

Zelenodolsk Designing and Engineering Office (Zelenodolsk, Russia):
E. N. Zhirkov, General director

Currently, in enterprises in the manufacture of shaped castings, heat-insulating shells made of mixtures of quartz sand, kaolin clay, ecowool, diatomite, perlite, graphite, peat, metal phosphate compounds and others are widely used. Among many components of heat-insulating mixtures, peat is a promising material. Thermal insulation shells made of peat mixtures are characterized as non-defi cient and environmentally friendly equipment. However, due to the low strength characteristics and a high degree of fire hazard, their widespread use in foundry is limited. Based on an analysis of the scientific literature, it was concluded that research on the development of effective thermal insulation shells of the hot top part of the mold is very relevant and in demand. The effect of phosphate borate compounds on the physicomechanical properties of heat-insulating shells made of the well-known peat-containing heat-insulating mixture was studied. It was experimentally established that the addition of phosphate sodium dimetaborate, phosphate sodium monotetraborate and phosphate sodium tripentarate to the peatcontaining heat-insulating mixture allows to increase its compressive strength in the wet state and tensile in the dry state. The highest values of the strength of the modified heat-insulating mixtures are achieved with a phosphate borate content of 9% (wt.). It was shown that modifying phosphate borate additives reduce friability, improve formability, lower the thermal conductivity of the peat-containing heat-insulating mixture, and the scientific forecast has been made to reduce their flammability and fire hazard. The new, effective heat-insulating mixture for the hot top of steel castings of the following composition,% (wt.) was developed: peat mass — 20; silica sand — 53; diatomite — 10; magnesium aluminum phosphate binder — 8; phosphate borate compound — 9.

1. Illarionov I. Е., Strelnikov I. А., Sadetdinov Sh. V., Moiseeva О. V., Korolev А. V. The effect of boric acid on the properties of insulating mixtures. Liteynoe proizvodstvo. 2019. No. 1. pp. 24–26.
2. Illarionov I. T., Sadetdinov Sh. V., Strelnikov I. A. Heat insulating mixture for insulation of castings shrinkheads. Patent RF No. 2688351. Applied: 14.11.2018. Published: 21.05.2019. Bulletin No. 15.
3. Nwaogu U. C., Tieje N. S. Foundry Coating Technology: A Review. Materials Sciences and Application. 2011. Vol. 2. pp. 1143–1160.
4. Veynova О. А., Kostikov А. А., Kuznetsov А. А. Method for thermal insulation of metal mirror of hot tops of large steel castings. Liteynoe proizvodstvo. 2011. No. 9. pp. 14–16.
5. Gatsuro V. М., Vovsya S. А. The use of exothermic inserts in the production of steel castings is the path to savings. Lityo i metallurgiya. 2008. No. 2. pp. 131–133.
6. Dibrov I. А. State and promising technologies for the development of foundry in Russia. Liteyshchik Rossii. 2013. No. 9. pp. 14–23.
7. Illarionov I. Е., Zhuravlev А. F. On the use of peat-containing heatinsulating mixtures with metal phosphate binders. Liteynoe proizvodstvo. 2011. No. 6. pp. 35–37.
8. Bazhin V. Yu. Struktural modification of petroleum needle coke by adding lithium on calcining. Coke and Chemistry. 2015. Vol. 58, lss. 4. pp. 138–142.
9. Boldin А. N., Davydov N. I., Zhukovskiy S. S. et. al. Foundry molding materials. Molding, core mixtures and coatings: handbook. Moscow: Mashinostroenie, 2006. 506 p.
10. Pat. 20130032689 A1 US. Foundry coating composition. M. J. Haanepen, F. W. von Piekartz, Y. Piekartz-Lutgendorff ; No. US 13/322836. Applied: 15.02.2011. Published: 07.02.2013.
11. Pat. 7507284 US. Sand casting pattern coating compositions containing graphite. V. LaFay, S. Neltner; № US 10/944471. Applied: 17.09.2004. Published: 23.03.2006.
12. Soshkin V. E., Molodykh L. А. Improvement of casting quality with exothermic inserts. Liteyshchik Rossii. 2013. No. 6. pp. 12–14.
13. Dovgal А. N., Kostikov А. А., Kuznetsov А. А., Chernomaz V. N. Layered graphite compounds. Vostochno-Evropeyskiy zhurnal peredovykh tekhnologiy. 2012. Vol. 6. No. 5. pp. 32–39.
14. Petrova N. V., Illarionov I. Е., Zhuravlev А. F., Muzyanov V. V. Development and research of peat-containing heat-insulating mixtures based on metal phosphate binders. Vestnik Chuvashskogo gosudarstvennogo pedagogicheskogo universiteta imeni I. Ya. Yakovleva. 2010. No. 4. pp. 153–158.
15. Lyuty R. V., Guriya I. М., Shapovalova D. V., Keush D. V. The formation of binder compositions based on phosphoric acid and metal salts in molding sand. Liteynoe proizvodstvo. 2013. No. 5. pp. 16–19.
16. Nazaratin V. V. Study of the effectiveness of insulating mixtures based on fly ash. Liteynoe proizvodstvo. 2009. No. 2. pp. 20–26.
17. Grachev А. N., Leushin I. О., Leushina L. I. Development of compositions of exothermic mixtures for steel and iron castings using wastes of thermal production. Chernye Metally. 2018. No. 2. pp. 39–43.
18. Nazaratin V. V. Novel heat-insulating mixtures. Metallurgiya. Mashinostroenie. 2008. No. 5. pp. 45–49.
19. Gelzard A., Mareche J. F., Furdin G. Modelling of exfoliated graphite. Progress in Materials Science. 2005. Vol. 50, Iss. 1. pp. 93–179.
20. Strelnikov I. E., Illarionov I. E., Zhuravlev A. F. Heat-insulating mixture for warming casting heads. Patent RF. No. 2455108. Applied: 03.05.2011. Published: 10.07.2012. Bulletin No. 19.
21. Illarionov I. E., Sadetdinov Sh. V., Strelnikov I. А., Gartfelder V. А. Influence of phosphate borate compounds on anti-corrosion stability of carbon steel in neutral water environment. Chernye Metally. 2018. No. 5. pp. 47–53.
22. Illarionov I. E., Pestryaeva L. Sh., Sadetdinov Sh. V., Moiseeva О. V. The effect of phosphate borate compounds on the physicomechanical properties of the furan mixture. Zagotovitelnoe proizvodstvo v mashinostroenii. 2019. Vol. 17. No. 8. pp. 339–341.
23. GOST 2138–91. Molding sands. General specifications. Introduced: 01.01.1993.
24. Technical Specification 5761-001-25310144–93. Diatomite. Introduced: 01.01.1994.
25. Technical Specification 6-18-10-11–85. Magnesiumaluminophosphate MAFS 20IK binder. Introduced: 01.01.1996.

26. GOST 17022–81. Graphite. Types, marks and general technical requirements. Introduced: 01.01.1982.
27. Medvedev Ya. I., Valisovskiy I. V. Technological testing of molding materials. Moscow: Mashinostroenie, 1973. 309 p.
28. Grachev A. N., Leushin I. O., Leushina L. I., Bokov M. S. Exothermal mixture for heating lost heads of steel and cast iron castings. Patent RF. No. 2601721. Applied: 11.03.2015. Published: 10.11.2016. Bulletin No. 31.
29. Korovin V. A., Leushin I. O., Tokarnikova O. V., Sedunov V. K. Sluzov P. A. Modifying mixture. Patent RF. No. 2553125. Applied: 13.03.2013. Published: 10.06.2015.
30. Illarionov I. E., Sadetdinov Sh. V., Moiseeva О. V., Strelnikov I. A. Improvement of the binding and strength properties of technical lignosulfonates. Liteyshchik Rossii. 2019. No. 5. pp. 30–33.
31. Nazaratin V. V., Dub V. S., Berman L. I., Kriger Yu. N. Drozhzhina M. F. Heatinsulation compound and casting mould. Patent RF. No. 2393048. Applied: 08.06.2008. Published: 27.06.2010. Bulletin No. 18.
32. Grachev А. N., Leushin I. О., Leushina L. I. The scheme for the use of industrial waste in foundries. Liteynoe proizvodstvo. 2016. No. 8. pp. 34–37.
33. Chernyshev Е. А., Evlampiev А. А. Development trend, technological features and prospects for the use of sand phosphate mixtures. Liteyshchik Rossii. 2009. No. 11. pp. 35–37.
34. Leonovich А. А. Chemical approach to the fire hazard reduction of wood materials. Pozharovzryvobezopasnost. 1996. Vol. 5. No. 1. pp. 10–14.
35. Trifonova О. N. Chemical modification of wood in order to reduce its combustibility. Pozharovzryvobezopasnost. 2018. Vol. 17. No. 1. pp. 23–25.