Explore the vast range of titles available.

Dry permanent magnetic separators have been widely used in the mineral and coal processing industries due to their simple operation and high separation efficiency. These tools not only discard some amount of bulk gangue from the raw ore, thereby reducing the volume of the grinding operation and cutting energy consumption, but also do not require water in the sorting process, thereby expanding their applicability to arid and cold areas. With the depletion of global iron ore resources, a dry, low-cost processing or pre-sorting prior to the wet separation has received the attention of industrial practitioners as a potential alternative. The performance of dry magnetic separators plays a critical role in dry processing This paper reviews the dry magnetic separators available in the literature and describes their operating principles, separation performance, and applications. A detailed comparison of different separators is also conducted to evaluate the differences in their sorting performance and mechanisms and to provide a reference for the optimization of dry magnetic separators.

This study examines the effect of smooth and humped flow channels on the recovery of industrial magnetic seeds in a drum magnetic separator. The results demonstrate that under varying feeding slurry quantities and drum rotational speeds, the humped channel consistently achieves higher recovery rates compared with the smooth channel, with an improvement of up to 3%. Scanning electron microscopy and vibrating sample magnetometry analyses of the samples reveal the presence of a small amount of impurities (predominantly consisting of elements, such as Al, Si, and Ti) in the industrial magnetite magnetic particles. These impurities exhibit lower magnetization, leading to reduced capture efficiency in the conventional smooth-channel drum magnetic separator. Simulations of the magnetic field, flow field, and particle trajectory indicate that the magnetic field force at the bottom of the smooth channel is only 0.6 kg2/(m·s4·A2), i.e., approximately 18 times lower than that at the roller surface. The incorporation of a humped channel shifts the impure magnetic seeds from a region with low magnetic field force to a region with higher magnetic field force, significantly enhancing the capture efficiency of the impure magnetic seeds.

Wet High-Intensity Magnetic Separators (WHIMSs) have become well established in mineral processing operations by efficiently separating particles based on their magnetic properties. While the existing literature extensively discusses WHIMS performance under varying operational conditions, there is a notable absence of attention to the degradation of coils over time and methods for its detection. In this paper, we address this gap by proposing a novel approach to detect coil degradation in WHIMSs, enabling timely maintenance interventions to maintain optimal performance. Through experimental analysis in an industrial environment, we show the significant effect of coil deterioration on WHIMS efficiency. We also introduce a real-time monitoring method using current measurements in coil sets. This method provides a practical solution for identifying and addressing coil degradation, helping to improve maintenance practices and sustain operational efficiency in mineral processing facilities. The experiments were conducted in a Brazilian iron ore processing company in Itabira, Minas Gerais.

Aerodynamic Drum Magnetic Separator (ADMS) uses an adjustable air flow to enhance the separation of magnetic particles from gangue. In order to explore the matching relationship between the magnetic field, the flow field, and the gravity field, as well as the capture and separation behavior of particles under the action of multi-physics, a related simulation model is established using the finite element software COMSOL Multiphysics and the accuracy of the simulation results is verified by measurement, formula calculation, and magnetic separation experiment. The trajectories and capture probabilities of particles in different magnetic fields and flow fields are calculated, as well as the critical airflow velocity corresponding to a specific capture probability. In addition, the magnetic field characteristics and particle capture effect of N-S alternate arrangement and N-N homopolar arrangement are compared by optimizing the permutation of magnetic poles. This model may provide a reference for the accurate control of magnetic separation enhanced by a coupling force field.

To date, the recovery of nickel and cobalt sulphide minerals from low-grade ores poses significant challenges in mineral processing due to their complex nature. With the decline of rich ore bodies, a paradigm shift to low-grade ores and secondary sources exists for these critical metals, particularly in the renewable energy sector, i.e. storage batteries. This study explores the potential consideration of the magnetic separator tailings obtained from Tati Nickel Mining Company in Botswana as a lucrative base metal secondary resource for the recovery of nickel, cobalt and copper. It becomes a dual approach to obtain valuable base metals while economically handling the waste material to ease the environmental challenges it was posing to the mine and the community. Characterisation of the samples obtained through crystallographic analysis, mineralogy and mapping, and elemental analysis showed the presence of nickel and copper minerals to a degree by which they can be economically extracted through hydrometallurgical means. Cobalt concentration in the sample was in trace amounts as it could only be detectable through the destructive technique. Concentration through froth flotation was conducted post characterisation, with emphasis on flotation time. The optimum flotation time was determined to be 3 minutes, giving metal recoveries of 15.56%, 27.40% and 52% for cobalt, nickel and copper respectively, with an enrichment ratio of 7.39 for copper. However, the yield obtained was 7.04% highlighting the ineffectiveness of the traditional concentration route previously practised in the mine. It was recommended therefore to re-design the flotation process and tailor it for the magnetic separator tailings, concentrating on the effects of pH and particle size distribution primarily, before the other factors, e.g. collectors, modifiers, etc. In conclusion, it was noted that the recovery of nickel, copper and the by-product iron was feasible; therefore, a recommendation was made to apply the Activox technology.

This article discusses the process flow chart for the recovery of the rare earthbearing minerals monazite and zircon. The results of this study show that 97.9% monazite with 0.006% yield and 61.2% recovery can be achieved from a feed sample containing 0.0096% monazite by using spiral, electrostatic and magnetic separators followed by flotation. When zircon is subjected to study the process mineralogy, it is observed that a zircon grade in the feed sample containing 0.028% zircon can be upgraded to a zircon grade of 98.7% at the yield of 0.006% and the recovery of 21.5%.

To enhance dry magnetic separation of fine-grained materials, our research team developed the pneumatic drum magnetic separator (PDMS), an airflow-aided magnetic separator. Different positions at the separation surface of PDMS have varied separation angles, so particles at different positions may be subjected to varying composite forces, resulting in a mismatch between airflow velocity and magnetic field intensity. However, because the separation process of PDMS is continuous and the separation of particles at a certain position is instantaneous, the separation performance of PDMS at a specific separation angle cannot be investigated. To evaluate optimal operating features at different separation angles, a laboratory dry pneumatic flat magnetic separator (DPFMS) was manufactured, which also makes the airflow pass through the separation plane in the opposite direction to the magnetic force. The separation performance of PDMS was revealed by separation tests for −0.15 + 0.074 mm artificial mixed ore with 0–0.6 m/s airflow on DPFMS at various separation angles. At separation angles of 70° and 90°, the separation efficiency increases with an increase in airflow velocity from 16.68% and 33.09% to 77.72% and 76.54%, respectively; at separation angles of 110°, the separation efficiency increases initially from 89.53% to 90.69%, then decreases to 88.22% and keeps decreasing. The synergistic relationship between airflow drag, magnetic force and gravity were investigated by analyzing the composite force and the motion trajectory of a single particle. The results show that the proper airflow velocity aids in enhancing the distinctions between magnetite and quartz particles in resultant force and movement. However, throughout a wide range of air velocity, while the airflow can improve magnetite and quartz separation efficiency of at small separation angles, it may diminish the separation efficiency at large separation angles.

Transverse-field high-gradient magnetic separators (HGMSs) are an important complement to longitudinal-field HGMSs in mineral processing due to their several advantages. However, the processing capacity of the transverse-field HGMS is smaller than that of the longitudinal-field HGMS. Consequently, research on the optimization of the matrix box for improving the processing capacity is essential. This work investigates the optimization of the matrix box for the SSS® HGMS to enhance the ilmenite separation efficiency and processing capacity. The results show that the matrix’s influence on separation performance is primarily influenced by the diameter of the rod matrix, the filling ratio, the depth of the matrix in the direction of slurry flow, and the ore unloading efficiency. Ilmenite pre-concentration tests are carried out using a test sample ore from Panzhihua, China. Pilot-scale validation research is carried out. The test results indicate that the depth of the matrix box should not be considerably thick, as an excessive number of layers increases the capture zone, but simultaneously reduces the unloading efficiency. The depth of the matrix box should neither be considerably thick nor particularly thin, as this would result in low processing capacity. Meanwhile, the segmented multi-layer matrix box should be used to balance the capturing and unloading performance. Finally, an optimal double-layer matrix ring is applied to the industrial transverse-field HGMS, and its inner and outer rings are equipped with matrix boxes with ϕ3 mm and ϕ2 mm rods, respectively, which improves its pre-concentrate efficiency and processing capacity. The concentrate indexes of the transverse-field HGMS is achieved with a TiO2 grade of 18.01% and a recovery of 87.28%, which is better than the separation indexes of the longitudinal-field HGMS.

The flotation process and magnetic separation are the most common methods for feldspar beneficiation containing approximately 0.4% Fe 2 O 3  and 0.04% TiO 2 . A model MIH (13) 111-5 Induced Roll dry high-intensity magnetic separator was used in this investigation to produce high-quality feldspar concentrate, and investigate the effects of magnetic field strength and roll speed on reducing coloring minerals. The best results were obtained at a magnetic field intensity of 16600 Gauss and a roller speed of 24 rpm. A feldspar concentrate containing 0.16% Fe 2 O 3 , 0.01% TiO 2  and 10.31% alkali minerals (K 2 O+Na 2 O) was obtained with a mass recovery of approximately 69.24%. As a result, the products that met the white glaze and ceramic requirements were produced.

High gradient magnetic separation is widely used in magnetic minerals upgrading, and its separation performance is significant depending on the parameters. In this investigation, the Mathematical model of the plate high gradient magnetic separator is established, the magnetic induction and the flow field distribution are investigated based on the COMSOL multi-physical simulation, and then the separation efficiency and TiO2 grade are analyzed using the plate high gradient magnetic separator. Additionally, the key factors affecting the efficiency of mineral separation are detailed in the experimental separation, the separation efficiency is demonstrated and its feasibility is verified by experiments. It is founded that the mathematical model and simulation results are basically validated by the experimental separation process, and the TiO2 grade can be effectively upgraded from 5.2% to 11.5% with the rinsing water consumption 9.5 L/min and the belt rotating speed 2 r/min. It is thus concluded that plate high gradient magnetic separator has provided an effective way in upgrading ilmenite quality.