http://dx.doi.org/10.5277/ppmp1845
Physicochem. Probl. Miner. Process., 54(2), 2018, 546-553 Physicochemical Problems of Mineral Processing
http://www.journalssystem.com/ppmp/
ISSN 1643-1049
© Wroclaw University of Science and Technology
Received May 16, 2017; reviewed; accepted September 18, 2017
Micaceous iron oxide production by application of magnetic
separation
Mehmet Tanriverdi, Sezai Sen, Tayfun Ciçek
Dokuz Eylul University, Engineering Faculty, Mining Engineering Department, Tinaztepe Campus, 35390, Buca, Izmir,
Turkey
Corresponding author: sezai.sen@deu.edu.tr (Sezai Sen)
Abstract: In this study, different flowsheet options were evaluated to achieve the best upgrading
conditions for a micaceous iron oxide ore. The first option included the recovery of micaceous iron
oxide particles using a double stage magnetic separation circuit after the grinding and classifying of
the ore into coarse (-1000+106 µm) and fine (-106 µm) size fractions. A belt type dry high gradient
magnetic separator (BHGMS) was used to beneficiate the coarse fraction. The concentrate of the
BHGMS was ground to -106 µm, and combined with the fine fraction produced at screening stage, and
subjected to high gradient magnetic separation (HGMS) at 1.2 T. A concentrate grading about 61.33%
Fe with 60.3% recovery was obtained applying the separation process incorporating BHGMS and
HGMS. A single stage separation circuit considering the use of HGMS after the grinding the ore below
106 µm was employed as the second concentration option. A concentrate having 63.80% Fe with 37.1%
weight recovery was obtained in this test. As the highest Fe grade and the lowest S concentration was
obtained by application of HGMS after the grinding the ore below 106 µm, and it was decided to
conduct a pilot scale study using pulsating HGMS. A concentrate assaying 69.45% Fe with 60.1%
weight recovery was produced by operating the pulsating HGMS at 0.6 T. The results showed that it
was possible to obtain a micaceous iron oxide concentrate to be used in pigment production using
magnetic separation method.
Keywords: micaceous iron oxide (MIO), magnetic separation, belt type high gradient magnetic separator, high
gradient magnetic separator, pulsating high gradient magnetic separator
1. Introduction
Natural iron oxides occur widely, and are exploited from a variety of deposit types. World iron oxide
pigment mine production in 2014 is given in Table 1. Micaceous iron oxide (also known as specular
hematite, specularite) is a variety of hematite mineral with a silvery metallic luster. It is mainly used in
pigment industry and in welding electrodes as a substitute for iron. Micaceous iron oxide is an
excellent pigment in paints providing physical protection for use in protective coatings for steel
constructions. The lamellar pigment particles in the paint orientate themselves as overlapping array of
parallel plates on the surface which offers greatly enhanced barrier protection against the corrosive
substances and water (Cornell and Schwertmann, 2003; Kalenda et al., 2004; Baena, et al., 2009; Ravi et
al., 2015). International Standard ISO 10601 requires >85% Fe
2
O
3
content in pigment quality micaceous
iron oxide concentrates. It also defines the lamellar grade of the concentrates according to the amount
of thin flake particles (ISO 10601).
As for the other iron ore types, gravity concentration, magnetic separation, and flotation processes
are promising methods for the beneficiation of micaceous iron oxide. Wang et al. (2011) conducted a
research study on a micaceous iron oxide ore containing 35% Fe using high intensity magnetic
separation and reverse flotation in sequence. A concentrate grading about 66.62% Fe with a weight
recovery of 30.65% was obtained in this study. Ravi et al. (2015) studied on a micaceous iron oxide ore