Morphological varieties of hematite and their redistribution between the products of beneficiation of screenings from crushing and screening plants of Kryvy Rih basin mines


  • O. S. Demchenko
  • V. D. Evtekhov
  • A. V. Evtekhova
Keywords: banded iron formation, Kryvyi Rih basin, rich iron ore, waste enrichment, screening of CSP, re-enrichment, hematite concentrate

Abstract

The deposits of high-grade ores of the Kryvyi Rih basin are developed by seven mines and two open pits. Insufficient quality of extracted ore mass requires its beneficiation at the crushing and screening plants operating at each mine. Utilizing three-stage crushing and three-stage screening methods sinter ore having iron content of 57-61 mass % (fine-grained (less than 20 mm) beneficiation product) is produced. The beneficiation waste is coarse-grained (20-100 mm) screening with an average iron content of 43 mass %. The authors studied the possibility of using this material as a secondary raw material for the production high-quality iron ore concentrate. According to the results of petrographic studies, it mainly consists of particles of hematite quartzites with an admixture of high-grade hematite ores, low-iron and iron-free rocks. The screenings have two-component mineral composition – hematite + quartz with insignificant admixture of kaolinite, calcite, aragonite, dolomite, pyrite, marcasite, millstone, relic silicates (chlorite, biotite, cummingtonite). Hematite, being the main ore mineral, is represented by three morphological varieties such as martite, micaceous hematite and dispersed hematite. The hematite redistribution between ore-preparation products (crushing, grinding to particle size of less than 0.1 mm) and screenings beneficiation was studied. Martite, which is a product of the hypergenic replacement of primary magnetite, represents a fine-porous differentiated aggregate, very small, multidirectional scaly crystals of hematite. Because of this, martite is subject to overgrinding in the ore preparation. The method of gravitational separation, which was used by the authors for beneficiation, allows most of the martite (particle size more than 0.02 mm) to get in the concentrate; and overgrinded martite (less than 0.02 mm) gets in beneficiation waste. In the process of grinding coarse-grained micaceous hematite (specularite) is effectively released and, when beneficiated, it gets in the concentrate. Thin-scaly aggregates of dispersed hematite are crushed to a particle size less than 0.01 mm and almost completely go to beneficiation wastes. Besides released particles of hematite and quartz, intergrown peaces having different proportions of these minerals are also formed in the course of grinding. During beneficiation process, high-grade aggregates with a hematite content more than 75% get in concentrates, the ones having the lower grade get into wastes. The different behavior of hematite of three morphological varieties in the course of ore preparation and beneficiation must be taken into account when developing an optimal technological scheme for the production of high-quality (67-69 mass.% of iron) hematite concentrate.

Author Biographies

O. S. Demchenko
Kryvyi Rih National University
V. D. Evtekhov
Kryvyi Rih National University
A. V. Evtekhova
Kryvyi Rih National University

References

1. Akimenko, N.M., Belevtsev, Ya.N., Goroshnikov, B.I., Dubinkina, R.P., Ishchenko, D.I., Karshenbaum, A.P., Kulishov, M.P., Lyashchenko, K.P., Maksimovich, V.L., Skuridin, S.A., Siroshtan, R.I., Tokhtuev, G.V., Fomenko, V.Yu., Shcherbakova, K.F. (1957), Geologicheskaja struktura i zheleznye rudy Krivorozhskogo bassejna [Geological structure and iron ores of the Krivoy Rog basin], Gosgeoltekhizdat press, Moscow, 280 (in Russian).
2. Belevtsev, Ya.N., Bura, G.G., Dubinkina, R.P., Yepatko, Yu.M., Ishchenko, D.I., Melnik, Yu.P., Strygin, A.I. (1959), Genezis zheleznyh rud Krivorozhskogo bassejna [Genesis of iron ores of the Krivoy Rog basin], Publ. house of Acad. of Sci. of the UkrSSR, Kyiv, 360. (in Russian).
3. Belevtsev, Ya.N., Kravchenko, V.M., Kulik, D.A., Belevtsev, R.Ya., Borisenko, V.G., Drozdovskaya, A.A., Yepatko, Yu.M., Zankevich, B.A., Kalinichenko, O.A., Koval', V.B., Korzhnev, M.N., Kusheev, V.V., Lazurenko, V.I., Litvinskaya, M.A., Nikolaenko, V.I., Pirogov, B.I., Prozhogin, L.G., Pikovskiy, Ye.Sh., Samsonov, V.A., Skvortsov, V.V., Savchenko, L.T., Stebnovskaya, Yu.M., Tereshchenko, S.I., Chaykin, S.I., and Yaroshchuk, M.A. (1991), Zhelezisto-kremnistye formacii dokembrija evropejskoj chasti SSSR [Banded iron Precambrian formations of the European part of the USSR]. Genesis of iron ores, Nauk. dumka, Kyiv, 216 (in Russian).
4. Belevtsev, Ya.N., Tokhtuev, G.V., Strygin, A.I., Melnik, Yu.P., Kalyaev, G.I., Fomenko, V.Yu., Zagoruyko, L.G., Molyavko, G.I., Polovko, N.I., Dovgan, M.N., Ladieva, V.D., Zhukov, G.V., Epatko, Yu.M., Shcherbakov, B.D. (1962), Geologija Krivorozhskih zhelezorudnyh mestorozhdenij [Geology of Kryvyi Rih iron ore deposits], Publ. house of Acad. of Sci. of the UkrSSR, Kyiv, UA, Vol. 1, 484 p. and Vol. 2, (in Russian).
5. Demchenko O.S., Evtekhov V.D. (2015) Petrografіchnyi sklad vіdsіvu drobarno-sortuvalnyh fabryk Krivorіzkogo baseinu [Petrographic composition of screenings from crushing and screening plants of the Kryvyi Rih basin] Sustainable development of industry and society. Section 5. Geology, applied mineralogy. Ecology. International scientific-technical conference proceedings. Kryvyi Rih: Kryvyi Rih natіonal university, 62-66 (in Ukrainian).
6. Evtekhov, V.D. (1997), Etapi formuvannja kompleksnoї mіneral'no-sirovinnoї bazi zalіzorudnih rodovishh Krivorіz'ko-Kremenchuc'kogo lіneamentu [Stages of formation of a complex mineral-raw material base of iron ore deposits of the Krivoy Rog-Kremenchug lineament]. Data of the Acad. of Mining Sci. of Ukraine, No. 4, 111-114 (in Ukrainian).
7. Gershoyg, Yu.G. (1955), Genezis rud Krivogo Roga [Genesis of the Krivoy Rog iron ore basin], Publ. house of Acad. of Sci. of the UkrSSR, Kyiv, 86-99 (in Russian).
8. Kanibolotsky, P.M. (1946), Petrogenezis porod i rud Krivorozhskogo zhelezorudnogo bassejna [Petrogenesis of rocks and ores of Krivoy Rog iron ore basin], Publ. house of Acad. of Sci. of the UkrSSR, Chernovtsy, 312 (in Russian).
9. Martynenko, L.I. (1955), Rol' gipergennyh processov v obrazovanii rud Saksaganskoj polosy Krivogo Roga [Geology and genesis of ores of the Krivoy Rog iron ore basin], Publ. Acad. of Sci. of UkrSSR, Kyiv, 100-113 (in Russian).
10. Smirnov O.Ya. (2014) Geology of low grade hematite ore deposits (hematite quartzites) of Valiavkinske deposit in Kryvyi Rih basin. Manuscript (in Russian).
Published
2018-03-30