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Pre-treatment, Concentration, and Enrichment of Precious Metals from Urban Mine Resources
Published in Sadia Ilyas, Hyunjung Kim, Rajiv Ranjan Srivastava, Sustainable Urban Mining of Precious Metals, 2021
Hyunjung Kim, Sadia Ilyas, Rajiv Ranjan Srivastava
Commercial magnetic units follow a continuous separation process on a moving stream of dry or wet particles passing through a low or high magnetic field. The various magnetic separators are drum, cross-belt, roll, high-gradient magnetic separation, high-intensity magnetic separation, and low-intensity magnetic separation.
Field Applications
Published in Ahmad Shahid Khan, Saurabh Kumar Mukerji, Electromagnetic Fields, 2020
Ahmad Shahid Khan, Saurabh Kumar Mukerji
Magnetic separation is a process in which magnetically susceptible material is extracted from a mixture using a magnetic force. This technique is useful in mining iron as it is attracted to a magnet. It is also used in electromagnetic cranes that separate magnetic material from scraps. Magnetic separators that used permanent magnets generate fields of low intensity only. High-intensity magnetic separators which employ electromagnets are found more effective in the collection of very fine paramagnetic particles
Magnetic Separation
Published in S. Komar Kawatra, Advanced Coal Preparation and Beyond, 2020
It is possible to separate coal from pyrite using magnetic methods. The differences in the magnetic properties of coal and pyrite are small enough, however, that either very high-intensity magnetic separators must be used or the magnetic properties of the pyrite must be enhanced. Magnetic separation can be carried out either wet or dry. Advantages of magnetic separation are its insensitivity to the coal chemistry, making it useful for oxidized coals, and its ability to remove locked coal/pyrite particles.
Differences in Early Rejection of Gangue for Low-Grade Iron Ores with Different Textures from HPGR
Published in Mineral Processing and Extractive Metallurgy Review, 2022
For these studies, the dry magnetic separation method was adopted using a low-intensity dry magnetic separator manufactured by Chengdu Leejun Industrial Co. Ltd, China. The dry magnetic separator used a combination of a rotating magnetic system and a non-concentric rotating drum to build a unique alternating and gradually weakening magnetic field. The magnetic field intensity of the drum surface was about 0.35 T at the highest. In addition, through the combined adjustment of the drum and the magnetic system rotating speed, that is, adjusting the magnitude of the centrifugal force and changing the N/S pole alternating frequency of the magnetic field, and the position of the separating plate, the product category and proportion can be adjusted. The dry magnetic separator can produce concentrate and tailing or further subdivide into concentrate, middling, and tailing, as shown in Figure 2. Low-intensity magnetic separation enabled non-magnetic or weakly magnetic gangue minerals to enter the tailings to achieve gangue rejection. The gangue mass yield and magnetic iron (mFe) recovery were estimated using Equations (1) and (2), respectively.
Variable importance assessments of an innovative industrial-scale magnetic separator for processing of iron ore tailings
Published in Mineral Processing and Extractive Metallurgy, 2022
A. Tohry, M. Jafari, M. Farahani, M. Manthouri, S. Chehreh Chelgani
Magnetic separation has been historically used for processing coarse iron ore particles. Over the last decade, magnetic separation has significantly improved in operability and performance. The relative magnetic field strength (MFS) for separation classifies magnetic equipment into three types: low-intensity magnetic separators (LIMS), medium intensity magnetic separators (MIMS), and wet high-intensity magnetic separators (WHIMS). Several factors need to be considered in selecting the appropriate magnetic equipment, such as particle size, degree of association of minerals in an ore (liberation degree), magnetic susceptibility of the targeted mineral and its gangue phases, as well as the capabilities of the magnetic equipment (Xiong et al. 1998; Hearn and Dobbins 2000; Svoboda 2001; Dobbins et al. 2007, 2009; Liu et al. 2013; Ren et al. 2015; Makhula et al. 2016; Li et al. 2018). LIMS is generally used for the scalping of simple ferromagnetic minerals such as magnetite. MIMS traditionally has been employed for separation of fine weak ferromagnetic minerals, and WHIMS mostly has been considered for separation of paramagnetic minerals such as hematite. Although WHIMS has several advantages, it is not suitable for the processing of fine and ultrafine particles. Moreover, another drawback through using WHIMS is that non-magnetic minerals may become entrapped among the magnetic minerals (Hearn and Dobbins 2000; Dahe 2002, 2003; Zeng and Dahe 2003; Chen et al. 2012).
Collector Chemistry for Bastnaesite Flotation – Recent Developments
Published in Mineral Processing and Extractive Metallurgy Review, 2019
Weiping Liu, Xuming Wang, Jan D. Miller
The rare earth minerals are mainly concentrated by gravity, magnetic, electrostatic, and froth flotation separation techniques. The typical gravity separation of rare earth minerals is found in the beneficiation of monazite from heavy mineral sands which is based on the differences in specific gravities (Gupta and Krishnamurthy 1992). Furthermore, gravity separation equipment, such as shaking tables, spiral concentrators, and conical separators, is used together with froth flotation in many rare earth separation plants in China. Magnetic separation is a common unit process to remove highly magnetic invaluable minerals, such as Fe-bearing minerals, or to concentrate paramagnetic rare earth minerals, such as monazite or xenotime (Gupta and Krishnamurthy 1992). Electrostatic separation is mainly used to separate monazite and xenotime from invaluable minerals with similar specific magnetic and gravity properties and to concentrate ultrafine coal particles containing rare earth elements (Higashiyama and Asano 1998). Froth flotation, which is the main separation technology for bastnaesite, as reviewed in this paper, is commonly used in Bayan Obo, China, and Mountain Pass, United States (Liu et al. 2016).