Author 1:
Name & Surname: Poperechnikova O. Yu.
Company: RIVS Science and Production Association (Saint-Petersburg, Russia)
Work Position: Head of subdivision
Contacts: e-mail: rivs@rivs.ru

Author 2:
Name & Surname: Shumskaya E. N.
Company: RIVS Science and Production Association (Saint-Petersburg, Russia)
Work Position: Principal Researcher
Scientific Degree: Candidate of Engineering Sciences

Author 3:
Name & Surname: Nagaeva S. P.
Company: RIVS Science and Production Association (Saint-Petersburg, Russia)
Work Position: Engineer–Mineralogist
Contacts: e-mail: SPN@yandex.ru

Implication of oxidized ferruginous quartzites as preproduction mining product in mineral dressing circuit is a promising and cost-effective way of enhancing production of concentrate without expansion of magnetite ore output. In magnetite ore mining and processing, oxidized ore makes 10–30 % out of which 90 % is lost in tailings. For recent 30 years foreign countries have mastered various technologies of dressing weak-magnetic, mainly hematite ore. Against order of the Inguletsky Mining-and-Processing Integrated Works (Ukraine), RIVS has accomplished R&D and semi-commercial testing aimed to assess practicality of oxidized quartzite processing. Currently unmined, hematite quartzites are the feedstock for Krivoi Rog MPIW and for future preparation plants of various MPIWs and mines in the Krivoi Rog Iron Ore Basin. In view of fine dissemination of oxidized quartzites extracted from Inguletsky deposit (in the mean, grains of hematite are 10–50 μm in size, grains of quartz are 50–70 μm in size), the main objective of the laboratory research was to find an optimal dressing method. Magnetic concentration of fine-disseminated ore is imperfect for: low contrast between properties of metallic and nonmetallic minerals as a consequence of a huge amount of intergrown pieces in coarse grinding; poor selectivity of magnetic concentration in fine grinding of ore up to 90–95 % content of 0.045 mm size grade, while the content of 10 μm size reaches 46.71 %; instability of magnetic concentration due to variability of material constitution and dissemination of oxidized quartzites. For these reasons, gravity concentration is low efficient. Thus, the only feasible method is flotation. The technology developed based on the research findings and its semi-commercial trail confirmed practicability of hematite ore processing.

1. Shumskaya E. N., Poperechnikova O. Yu. Razrabotka effektivnoy tekhnologii obogashcheniya okislennykh zhelezistykh kvartsitov (Development of efficient concentration technology of oxidized ferruginous qurtzites). Gornyi Zhurnal = Mining Journal. 2012. No. 11. pp. 52–55.
2. Nagaraj D. R. et al. Non-Sulfide Mineral Flotation: An Overview, Proceedings of Symposium. Honoring M. C. Fuerstenau. Society of Mining, Metallurgy and Exploration Inc., Littleton, CO, 1999.