Ural State Mining University (Ekaterinburg, Russia):

Pelevin A. E., Professor, Doctor of Engineering Sciences, Associate Professor, a-pelevin@yandex.ru

EVRAZ KGOK (Kachkanar, Sverdlovsk region, Russia):
Sytykh N. A., Head of Production Control Department

This study covers the grinding and concentration technology for magnetite and titanomagnetite ores. With regard to these ores, it is suggested to evaluate the efficiency of respective grinding stages not only by the performance indicators of mills and sizing equipment, but also by the indicators of respective magnetic separation stages, in view of the inextricable link between grinding and concentration stages in magnetite ore concentration circuits. It is shown that magnetite iron recovery into the magnetic product of advanced drum separators exceeds 97 %. The yield of the nonmagnetic product relative to the grinding or crushing stage characterizes the degree of minerals opening by the mill or crushers. Therefore, the grinding efficiency for the magnetite or titanomagnetite ore (middlings of wet magnetic separation) may be additionally evaluated by the specific yield of the mill in terms of opened rock minerals. The maximum opening of titanomagnetite ore minerals is achieved during the first and second grinding stages. During the third grinding stage, the opening of rock minerals is significantly lower. This suggests a possibility of converting from three-stage to two-stage grinding. The study includes the results of industrial tests of two-stage grinding circuits for the titanomagnetite ore with an estimate of respective performance indicators of the mill, hydrocyclones, screens and magnetic separators. For Kachkanarsky GOK, a circuit with verification classification and control screening in the second stage is found to be the most promising of the available two-stage circuits. Implementation of this circuit would require additional installation of a screen and an increased-capacity pump and an increase in the number of hydrocyclones and magnetic separators. The circuit tested enables a reduction of titanomagnetite ore grinding costs.

1. Pelevin A. E., Sytykh N. A. Iron concentrate stage separation by means of drum magnetic separator with modified separating bath. Obogashchenie Rud. 2016. No. 4. pp. 10–15. DOI: 10.17580/or.2016.04.02.
2. Collinao E., Davila P., Irarrazabal R., de Carvalho R., Tavares M. Continuous improvement in SAG mill liner design using new technologies. XXVII International Mineral Processing Congress (IMPC). Santiago, Chile, 2014. Сhap. 8. Comminution processes. pp. 104–118.
3. Rosa A. C., de Oliveira P. S., Donda J. D. Comparing ball and vertical mills performance: An industrial case study. XXVII IMPC. Santiago, Chile, 2014. Сhap. 8. Comminution processes. pp. 44–52.
4. Jankovic A., Valery W., Sönmez B., Oliveira R. Effect of circulating load and classification efficiency on HPGR
and ball mill capacity. XXVII IMPC. Santiago, Chile, 2014. Сhap. 9. Energy efficiency in comminution. pp. 2–14.
5. Baranov V. F., Patkovskaya N. А., Tasina Т. I. Current trends in magnetite iron ores processing technology. Basic trends. Obogashchenie Rud. 2013. No. 3. pp. 10–17.
6. Pelevin A. E., Mushketov A. A. Election and optimization of the closed cycle grinding equipment based on transformation models of size distribution and separation characteistics of separation devices. Izvestiya Vuzov. Gornyi Zhurnal. 2014. No. 5. pp. 120–128.
7. Malyarov P. V. Upon ball mill combination liner design. Obogashchenie Rud. 2017. No. 3. pp. 10–14. DOI: 10.17580/or.2017.03.02.
8. Plochberger T., Baqueiro Avila M. Development of an energy optimized stirred media grinding mill. Berg und Hüttenmännische Monatshefte. 2014. Vol. 159, Iss. 6. pp. 253–258.
9. Jianjun Tian, Changjiu Zhang, Chunmin Wang. Operation and process optimization of sino iron ore’s autogenous milling circuits: The largest in the world. XXVII IMPC. Santiago, Chile, 2014. Chap. 8. Comminution processes. pp. 141–153.
10. Malyshev V. P., Turdukozhaeva A. M., Kaikenov D. A. Probabilistic model of wet grinding process in ball mill. Obogashchenie Rud. 2013. No. 1. pp. 27–30.
11. Pelevin А. Ye., Lazebnaya М. V. Application of «Derrick» screens in locked grinding circuit at the «KMAruda» Mining Complex concentrating plant. Obogashchenie Rud. 2009. No. 2. pp. 4–8.
12. Opalev A. S., Shcherbakov A. V. Development and introduction of innovative energy-saving technology of ferrous quartzite beneficiation at JSC «Olkon». Innovative technologies of mineral and technogenic raw materials beneficiation: materials of scientific and technical conf. held in the framework of the VI Ural Mining Industrial Forum, December 2–4, 2015. Ekaterinburg: UGGU Publ., 2015. pp. 125–131.