LLC “Magnezit Group”, Moscow, Russia:

L. M. Akselrod, Technical Director

LLC “Magnezit Group”, Satka, Chelyabinsk region, Russia:
T. V. Yarushina, Head of Administrative Department of Technological Developments
I. G. Maryasev, Head of Laboratory of Materials Science (Department of Technological Developments)

LLP “Dalmond”, Pavlodar, Kazakhstan:
V. L. Nechunaev, Executive Officer of the Representation in the Republic of Kazakhstan

This article studies the wear factors of lining in zinc Waelz-kiln and presents the results of scientific-research work, which aims to increase its durability. Special attention was paid to a technology for production of chromite-periclase refractories. It also discusses a contemporary method for perfecting the structure of chromite-periclase refractories, which is based on analysis of corrosion effect on their reaction charge. A method for modeling a process of introducing a melt of reaction charge into refractory structure was developed. Refractories wear was determined in a Waelz-kiln according to a frontal scheme through a series of consequent transformations of their microstructure. Based on the results of researching corrosion of refractory products under the influence of fayalite slag, chemical composition of such chromite-periclase refractories was chosen (more resistant to the components of materials that undergo the Waelz-process). The most important advantage of the recommended refractories (brand GMHP-2SP) is their low thermal conductivity and gas permeability of the structure, as well as the occurrence of protective characteristics of the matrix during their operation, which is due to complex spinelide forming (Mg, Fe, Zn)(Fe, Al, Cr)₂O₄ along the boundaries of periclase grains, protecting the latter from corrosion. Structural changes of refractories under the influence of corrosion materials in the samples after tests, performed in a rotary kiln, are consistent with analogue structural changes in the samples that were cut out from lining after industrial testing of the GMHP-2SP chromite-periclase refractories. The usage of these refractories for lining of Waelz-kiln reaction zone ensured a stable conduction of the highly productive technological process and increased the overhaul interval.

1. Gusev Yu. P. TOO “Kaztsink”: rasshirenie, modernizatsiya, innovatsionnoe razvitie (“Kazzink” enterprise: expansion, modernization, innovation development). Gornyi Zhurnal = Mining Journal. 2011. No. 9. pp. 15–18.
2. Kozlov P. A. Velts-protsess (Waelz-process). Moscow : “Ore and Metals” Publishing House, 2002. 176 p.
3. Assis G. Emerging pyrometallurgical process for zinc and lead recovery from zinc-bearing waste materials. Proceedings of 37th Zinc and Lead Processing Symposium (CIM Meeting). Calgary, Canada, 16–19 August 1998. pp. 243–265.
4. Parry R., Brazier D., Courtney T., Knupfer P., McEwan N. The product development process for smelter refractories: a text book and practice pers pective. Refractories 2010 International Conference. Johannesburg, 16–17 March 2010. pp. 87–100.
5. Gregurek D., Majcenovic C., Spanring A., Kirschen M. Wear of basic refractories in the non-ferrous metals industry. 56th International Colloquium on Refractories. Aachen, Germany, 25–26 September 2013. pp. 162–167.
6. Slovikovskiy V. V., Gulyaeva A. V. Effektivnye vysokostoykie futerovki veltspechey (Efficient high-resistant linings of Waelz-furnaces). Novye ogneupory = Refractories and Industrial Ceramics. 2014. No. 8. pp. 3–7.
7. Strelov K. K. Struktura i svoystva ogneuporov (Structure and properties of refractories). Moscow : Metallurgiya, 1982. 208 p.
8. Jochen Allenstein et al. Ogneupornye materialy. Struktura, svoystva, ispytaniya : spravochnik (Feuerfeste Werkstoffe. Aufbau, Eigenschaften, Prüfung : Auflage). Ed.: G. Routschka, H. Wuthnow. Translated from German. Moscow : Intermet Engineering, 2010. 392 p.
9. Fotoyi N. Z., Eric R. H. Interaction of MgO–MgR₂O₄ (R: Al, Cr, Fe) with SO₂-containing gasess. Southern African Pyrometallurgy 2011 International Conference. Johannesburg, 6–9 March 2011. pp. 373–388.
10. Lange M., Garbers-Craig A. M., Cromarty R. Wear of magnesia-chrome refractory bricks as a function of matte temperature. The Journal of The Southern African Institute of Mining and Metallurgy. 2014. Vol. 114, No. 4. pp. 341–346.
11. Gregurek D., Spanring A., Breyner S., Ressler A. High Performance Refractory Brands for the Nonferrous Metal Industry. RHI Bulletin. 2012. No. 2. pp. 50–54.
12. Gregurek D., Prietl T., Breyner S. B., Ressler A., Berghofer N. M. Innovative magnesia-chrome fused grain material for non-ferrous metals refractory applications. Proceedings of the Fifth International Platinum Conference “Platinum 2012”. Available at: http://www.saimm.co.za/Conferences/Pt2012/251-260_Gregurek.pdf