Journal of Chemical Technology and Metallurgy, 53, 5, 2018

990

A DEVELOPMENT OF THE ADAPTIVE TECHNOLOGY OF SINTER PRODUCTION AT PJSC MMK

Salavat K. Sibagatullin1, Alexander S. Kharchenko1, Alexander S. Savinov1, Valentin N. Selivanov1, Dmitry N. Gushchin1, Igor P. Mazur2

ABSTRACT

The adaptive technology of sinter production and pig iron smelting at PJSC MMK was studied when replacing the pellets of Sokolov-Sarybai Mining Production Association (SSGPO) JSC (further referred to as SSGPO) with pellets from other producers in the blast furnace charge and when increasing their share in the charge. Technological adaptation of the sinter production and cast iron production processes aiming at the manufacture of products with required properties has the following main components: adaptation of the composition and properties of the components of sinter and blast furnace charge; adjustment of the sinter and blast furnace production parameter level (parametric adaptation); change of the sequence and/or the set of technological operations (structural adaptation).

In the blast-furnace shop, the consumption of SSGPO pellets was lowered and then increased with a reverse change in the consumption of pellets from other producers. The content of pellets in the furnace charge was first increased and then lowered. The consumption of pellets of all types was in the range of 515 - 649 kg/t of pig iron, which corresponded to the content of pellets in the iron ore portion of the charge 31.8 - 42.0 %. The development of an adaptive technology for sinter production increased its basicity by CaO/SiO2 in the range 1.68 - 2.01 with a decrease in the share of SSGPO pellets and an increase of pellets total share in the furnace charge.

As a result, a 0.1 unit increase in basicity coincided with 0.047 % absolute decrease in the content of 5 - 0 mm class fines in sinter. The increase in impact strength according to GOST 15137-77 was 0.89 % abs., the decrease in abrasion was 0.149 % abs. At the same time, a 0.1 unit increase in basicity coincided with a 0.29 % abs. increase of “hot” strength LTD+6,3 according to ISO 13930: 2007. The increase in sinter strength had a positive effect on the gas dynamics of the blast-furnace process, which allowed smelting with an increased consumption of natural gas.

Keywords: sinter, pellets, cold and hot strength, charge basicity, sinter machine productivity.

Received 04 May 2018Accepted 15 June 2018

Journal of Chemical Technology and Metallurgy, 53, 5, 2018, 990-994

1 Nosov Magnitogorsk State Technical University 38 Lenina Avenue 455000 Magnitogorsk, Chelyabinsk Region, Russia E-mail: 10tks@mail.ru; E-mail: as.mgtu@mail.ru2 Lipetsk State Technical University, 30 Moskovskaya St. 398600 Lipetsk, Russia

INTRODUCTION

The development strategy of PJSC Magnitogorsk Iron and Steel Works provides for further improvement of metal production along with overcoming the conse-quences of the global financial crisis. In these conditions, it is necessary to timely adapt the enterprise to the chang-ing conditions, introducing new technological solutions to improve the quality of intermediate and final products and to reduce material costs for metal production. Sinter production with its approximate 65 % supply of iron ore

contributes to achieving this strategic goal.Due to the joint use of sinter and pellets in blast fur-

nace smelting, it is expedient for an enterprise to use an adaptive sinter production technology which takes into account the properties of pellets used and their content in the blast furnace charge. The pellets currently used are non-fluxed. Therefore, an increase in their content in the blast furnace charge necessitates an increase in sinter basicity in order to exclude the introduction of raw limestone to the blast furnace charge, thus preventing the corresponding deterioration of the furnace performance.

Salavat K. Sibagatullin, Alexander S. Kharchenko, Alexander S. Savinov, Valentin N. Selivanov, Dmitry N. Gushchin, Igor P. Mazur

991

An increase in sinter basicity is also necessitated by the replacement of pellets with an increased basicity by pellets with a lower basicity.

The growth in sinter basicity provides conditions for changing its other quality indicators. An increase in basicity depending on the interval of its change can both improve and deteriorate one and the same quality index [1, 2]. Among the set of sinter quality indicators, some part can change in a favorable direction, another – in an unfavorable direction [2, 3]. Therefore, the adaptive technology of sinter production was studied on the ex-ample of PJSC MMK sintering plant and the smelting of pig iron on the example of a blast furnace when SSGPO pellets in the blast furnace charge were substituted with pellets from other manufacturers and their share in the charge increased.

EXPERIMENTAL

The adaptive impact principle corresponds to the world production practice [4 - 12]. The majority of known methods of adaptive control imply that it is constructed by evaluating real production results. A new methodological approach has been developed at the Magnitogorsk State Technical University including ad-ditional computer modeling of the process with an early forecast of the complex of parameters being formed and subsequent certification tests [13 - 14].

The technological adaptation of the sintering pro-cess to manufacture products with required properties includes the following main components:

- adaptation of the composition and properties of the components of the sinter charge;

- adjustment of the sinter production parameter level (parametric adaptation);

- change of the sequence and/or the set of techno-logical operations (structural adaptation).

The use of the manufactured sinter requires a technological adaptation of blast furnace smelting with similar components.

In the blast furnace shop, the consumption of SS-GPO pellets was lowered and increased with a reverse change in the consumption of pellets from other produc-ers, predominantly from Mikhailovsky, Lebedinsky and Kostomuksha mining and processing plants (GOK). The content of pellets in the furnace charge was first increased, then lowered. The consumption of SSGPO

pellets was in the range of 0 - 198, of Mikhailovsky pellets 210 - 425, of Lebedinsky pellets 41 - 192, of Kostomuksha pellets 70 - 181, of all types 515 - 649 kg/t of pig iron. At the same time, the consumption of sinter was reduced and increased in the range of 958 - 1119 kg/t of pig iron. The content of pellets in the iron ore portion of the furnace charge was 31.8 - 42.0 %, that of sinter was 58.0 - 68.2 %. The development of an adaptive technology for sinter production increased its basicity by CaO/SiO2 in the range of 1.68 - 2.01 with a decrease in the share of SSGPO pellets and an increase of pellets total share in the furnace charge. Correspondingly, the basicity of sinter was reduced at a reverse change in the composition of the blast furnace charge.

RESULTS AND DISCUSSION

The increase in the flux content in the sinter charge (Fs, %) for this increase in basicity was characterized by the expression(СаО/SiO2)s = 1,23 + 0.07 Fs. (1)

Consequently, a 1 % increase in the flux content increased sinter basicity by 0.07 units.

The dependence of the demand for coke breeze (Кs, kg/t of sinter) on basicity in the range of its decrease and subsequent increase was characterized by the expressionКs = 54.0 – 5.47 (СаО / SiO2)s (2)

Consequently, a 1% increase in basicity lowered the coke breeze consumption by 0.55 kg/t of sinter.

The height of the burden layer was maintained at 292 mm. The rarefaction after cyclones was in the range of 9.6 - 11.0 KPa, decreasing with the increase of sinter basicity. The increase in flux consumption led to a de-crease in the iron content in sinter according to Fig. 1.

A 0.1 unit increase in basicity coincided with 0.28 % of abs. reduction in iron content, 0.29 % of abs. decrease in FeO content and 0.005 % of abs. growth in sulfur content, 12°C of sinter temperature reduction after the cooler. The recovery yield decrease was 4.5 kg/t of sinter.

The results of tests in the tumbler in accordance with GOST 15137-77 showed that the sinter impact strength factor (+5 mm class components after breakage) and abrasion (-0.5 mm class components after breakage) depended on basicity according to Figs. 2 and 3.

A 0.1 unit increase in basicity coincided with 0.89 % of abs. increase in strength and 0.149 % of abs. abra-sion reduction.

Journal of Chemical Technology and Metallurgy, 53, 5, 2018

992

In the fractional makeup of sinter, it was most sig-nificant that the 10 - 5 mm class content decreased with an increase in the 25 - 10 mm fraction content, which is most preferable for blast furnace smelting. A 0.1 unit of basicity growth coincided with 0.047 % of abs. reduction of 5 - 0 mm class fines content. The increase in “hot” strength LTD+6,3 was 0.29 % abs.

The productivity of sinter machines (Ps, t/h) by commercial sinter increased in accordance with the expressionPs = 87.1 + 1.81 (СаО / SiO2)s (3)

Therefore, a 0.1 unit increase in basicity corre-sponded to an increase in productivity of 0.18 t/h.

The productivity of sinter machines by iron (PFe, t/h) decreased (Fig. 4) in accordance with the expressionPFe = 52.6 – 1.52 (СаО / SiO2)s (4)

A 0.1 unit increase in basicity coincided with a

decrease of 0.15 t/h (0.31 %) in productivity by iron.It was established that sinter “hot” strength influ-

ences the possibility of reducing the specific coke consumption by increasing the specific consumption of natural gas. A 0.1 % increase of the LTD+6,3 factor coincided with an increase in natural gas consumption by about 1.1 m3/t of pig iron. According to the results of tests at one of the blast furnaces, the following rational composition of the iron ore portion of the charge was obtained: sinter content 62 - 63 %, its CaO/SiO2 basicity approx. 1.85; pellet content 37 - 38 %.

CONCLUSIONS The joint use of sinter and pellets in PJSC MMK

blast furnaces necessitates taking into account the properties of pellets used and their content in the charge in the technologies of sinter production and pig iron

Fig. 1. Reduction of iron content in sinter from sinter plant # 2 with an increase in its basicity.

Fig. 2. Reduction of sinter strength with an increase in its basicity.

Fig. 3. Reduction of sinter abrasion with an increase in its basicity.

Fig. 4. Decrease in sintering machines productivity by iron with an increase in sinter basicity.

Salavat K. Sibagatullin, Alexander S. Kharchenko, Alexander S. Savinov, Valentin N. Selivanov, Dmitry N. Gushchin, Igor P. Mazur

993

smelting. At PJSC MMK, for 9 months, SSGPO pellets were gradually withdrawn from the blast furnace charge being substituted with pellets from other manufacturers, and the share of sinter was decreased, then the process was reversed.

A decrease in the consumption of SSGPO pellets with their replacement by pellets from other manu-facturers with an increase in the total share of pellets in the charge necessitated the adaptation of the sinter production technology.

A 0.1 unit increase in sinter basicity coincided with 0.55 kg/t of sinter for the reduction in coke breeze con-sumption, 0.28 % reduction in iron, 0.29 % decrease in FeO and 0.005 % increase in sulfur content.

A 0.1 unit increase in basicity, with its decrease and a subsequent increase varying in the range from 1.68 to 2.01, coincided with a 0.18 t/h increase in sinter machine productivity by commercial sinter. At the same time, iron productivity decreased by 0.15 t/h (0.31 %).

There were changes in the sintering process. A 0.1 unit increase in basicity coincided with 12°C of sinter temperature reduction as a result of a spontaneous increase in the efficiency of its cooling on the cooler. A 0.225 kPa decrease in the rarefaction after cyclones indicated an increase in the gas permeability of the sintered layer with a decrease in the recovery yield of 4.5 kg/t of sinter.

A 0.1 unit increase in basicity coincided with a 0.047 % of abs. decrease in the fines content of 5 - 0 mm class in sinter. The increase in impact strength according to GOST 15137-77 was 0.89 % abs., the decrease in abrasion was 0.149 % abs. At the same time, a 0.1 unit increase in basicity coincided with a 0.29 % abs. increase of “hot” strength LTD+6.3 according to ISO 13930: 2007.

Acknowledgements The research has been carried out in the framework

of the state order of the Ministry of Education and Sci-ence of the Russian Federation according to the project № 11.8979.2017/БЧ.

REFERENCES

1. E.F. Wegman, et al. (ed. by Yu.S. Yusfin) Metallurgy of cast iron, Moscow, Academic Book, 2004, p. 774, (in Russian).

2. N.N. Babarykin, Theory and technology of the blast

furnace process, Magnitogorsk, MSTU, 2009, p. 257, (in Russian).

3. S.K. Sibagatullin, T.V. Mayorova, A.V. Chevy-chelov, V.A. Gostenin, K.V. Senkin, A comparison of the properties of OJSC MMK stabilized sinter and SSGPO pellets, Vestnik of Nosov Magnitogorsk State Technical University, 27, 3, 2009, 23-25, (in Russian).

4. Hong-Seok Park, Ngoc-Hien Tran, An autonomous manufacturing system for adapting to disturbances, The International Journal of Advanced Manufactur-ing Technology, 56, 9-12, 2011, 1159-1165.

5. Hong-Seok Park, Ngoc-Hien Tran, A cognitive agent based manufacturing system adapting to distur-bances, International Journal of Control, Automation and Systems, 10, 4, 2012, 806-816.

6. Marc B. Sokol, Adaptation to difficult designs: Facilitating use of new technology, Journal of Business and Psychology, 8, 3, 1994, 277-296.

7. Namwoon Kim, Jae H. Pae, Utilization of new technologies: organizational adaptation to business environments, Journal of the Academy of Marketing Science, 35, 2, 2007, 259-269.

8. Ulrich Müller, Simulation of a real-time process adaptation in the manufacture of high-density fibreboards using multivariate regression analysis and feedforward control/Martin Riegler, Bernhard Spangl, Martin Weigl, Rupert Wimmer, Wood Sci-ence and Technology, July 2013.

9. Seid Žapþeviü, Peter Butala, Adaptive process control based on a self-learning mechanism in au-tonomous manufacturing systems, The International Journal of Advanced Manufacturing Technology, 66, 9-12, 2013, 1725-1743.

10. Claudio A. Policastro, André C.P.L.F. Carvalho, Alexandre C.B. Delbem, A hybrid case adaptation approach for case-based reasoning, Applied Intel-ligence, 28, 2, 2008, 101-119.

11. E.M. Golubchik, Metal products adaptive quality management, Vestnik of Nosov Magnitogorsk State Technical University, 27, 1, 2014, 63-69, (in Rus-sian).

12. E.M. Golubchik, A.S. Kuznetsova, G.Sh. Rubin, G.S. Goun, Kh. Dyya, The application of the model and principles of technological adaptation of quality indicators in the processes of metalware production, Vestnik of Nosov Magnitogorsk State Technical

Journal of Chemical Technology and Metallurgy, 53, 5, 2018

994

University, 14, 1, 2016, 101-106, (in Russian).13. M.V. Chukin, A.S. Kuznetsova, D.G. Emaleeva,

Analysis of the possibility of producing fasteners of an increased quality grade from carbon structural steel with an ultrafine grain structure. Forging-stamping pro-duction, Metal forming, 1, 2012, 41-45, (in Russian).

14. M.V. Chukin, A.S. Kuznetsova, M.P. Baryshnikov, Determination of the possibility of achieving high quality grades of bolts from carbon steel with an ultrafine grain structure using the Brinell scale, Bulletin of Voronezh State Technical University, 8, 4, 2012, 150-152, (in Russian).