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Compared with wet magnetic separation, dry magnetic separation has the advantages of saving water resources, short beneficiation process, less equipment investment, less floor space and low beneficiation cost. The grade of iron ore resources in China is getting lower and lower, and the dispersed grain size is line, so it is urgent to develop dry magnetic separator for line-grained materials. According to the structure and working principle of various types of dry magnetic separators, they are divided into several types, such as magnetic-gravity combined dry magnetic separator, direct feeding wind-gravity- magnetic combined dry magnetic separator, wind feeding dry magnetic separator and so on. Magnetic gravity combined dry magnetic separators mainly include fixed magnetic system barrel dry magnetic separator, double roll high intensity dry magnetic separator, bet rotating magnetic field dry magnetic separator, double ring moving magnetic system dry magnetic separator, dry high intensity magnetic plate separator, dry screen high intensity magnetic separator, vibrating high gradient dry magnetic separator and other typical types. Dred feeding wind-gravity-magnetic combined dry separator mainly includes wind drum dry magnetic separator, wind feeding dry magnetic separator, cylinder fluidized dry magnetic separator, three-stage dry permanent magnet cylinder magnetic separator? wind-magnetic coupling dry magnetic separator? dry wind-magnetic separator? wind-gravity-magnetic combined force field magnetic separator and other typical types. Wind feeding dry magnetic separator mainly includes wind feeding plate magnetic separator? new dry wind-magnetic combined magnetic separator? dry wind permanent magnet concentrator? wind feeding dry permanent magnet magnetic separator and other types. The structure? magnetic separation principle? characteristics and application scope of more than 20 kinds of dry magnetic separators are introduced? and the advantages and disadvantages of various dry magnetic separators are analyzed. [ABSTRACT FROM AUTHOR]

As a product of hydrothermal mineralization at spreading centers, seafloor massive sulfides (SMS) have become a research hotspot in the field of prospecting and exploring deep-sea mineral resources owing to their enrichment of various strategic metals. Since hydrothermal circulation changes the magnetic properties of host rocks and can generate magnetic anomalies, near-bottom magnetic surveying is an effective method to determine magnetic anomaly features of the seafloor. This technology has been applied to the detection of SMS deposits, in addition to its use in understanding hydrothermal fluid flow conduits and associated hydrothermal alterations. The Tianxiu Vent Field (TVF) is a detachment-fault-controlled, ultramafic-associated hydrothermal system located on the Carlsberg Ridge, Northwest Indian Ocean. During China's DY57th cruise in 2019, near-bottom magnetic data were collected by an autonomous underwater vehicle. In this paper, we use bathymetric and magnetic data, as well as rock sampling information, to analyze and discuss the magnetic anomaly features of the TVF region. Then, we apply 2.5D magnetic anomaly profile forward modeling to determine the shallow magnetic structure and the pattern of detachment faults in the subsurface. Our results show that TVF is characterized by a significant positive magnetic anomaly, where stronger magnetization exists in the area with active hydrothermal vent clusters. The detachment fault has a dip of less than 30° at shallow depths, which steepens to a dip of ~70° at depths of around 300 m. [ABSTRACT FROM AUTHOR]

In order to study in detail the characteristics of the lithospheric magnetic field and underground magnetic susceptibility structure in the East Dabie region of China, the magnetic data have been collected at 108 geomagnetic total intensity measuring points and 65 geomagnetic profile measuring points located in this region. Using a matching filter method and inverting the underground magnetic susceptibility of the medium, shallow and deep models of the lithospheric magnetic field, Curie-isothermal surface depth distribution and magnetic structure model of the underground medium have been obtained. The results show that the lithospheric magnetic field in the East Dabie region is distributed as a positive anomaly band or mass in the Jianghuai uplift, Tanlu fracture belt and the lower Yangtze uplift. In the North Huaiyang fold belt, it passes through with a huge negative anomaly in an E–W direction. Comparing the lithospheric magnetic field with the superficial magnetic field, strikes and cutting depths of several buried faults in this area can be found. The deep lithospheric magnetic field reflects the distribution and composition of the crustal basement in the region to a certain extent. The Curie-isothermal surface depth in the interior can be used to reveal the distribution of magmatic activity in the study area. Some deep and large faults have a certain controlling effect on the distribution of magnetic structures, and the epicenters of earthquakes in Dabie Mountain are concentrated in horizontally high magnetic structures. The above research is of great significance for studies of the lithospheric magnetic field and the relationship between underground magnetic structure and deep structure in the East Dabie region. [ABSTRACT FROM AUTHOR]

The Changning area is located in the southern Sichuan basin and the western Yangtze Plate and is the most abundant shale gas exploration area in China. In recent years, Changning has experienced frequent earthquakes with moderate magnitudes, attracting extensive interest. To investigate the magnetic characteristics in Changning, 952 land-based stations were employed to establish a magnetic anomaly model with a resolution of 2 km, and the subsurface magnetic basement structure was obtained by an iterative algorithm in the Fourier domain. The magnetic anomaly model shows significant distinctions between the northern salt mine area and the southern shale gas area. The magnetic basement includes the crystalline basement and the Sinian sedimentary rock metamorphic basement, which has strong magnetism. The large intracratonic rift that developed in the Sinian–Early Cambrian plays an important role in the evolution of Changning, which also impacts magnetic anomalies and the magnetic basement structure. Finally, by comparing the seismic wave velocity ratio structure, the deeper magnetic basement that corresponds to the higher seismic wave velocity ratio can be explained. This article implies that magnetic anomalies and magnetic basement depth have a certain correlation with earthquakes in Changning, and it provides a geodynamic reference for Changning and the southern Sichuan basin. [ABSTRACT FROM AUTHOR]

A magnetic field configuration of an island divertor for a quasi-axisymmetric stellarator (CFQS) is proposed. The configuration incorporates large islands surrounding the core confinement region. The interface between the core region and the peripheral region of the island divertor is a clear magnetic separatrix similar to a tokamak divertor. The structure of divertor magnetic field lines is very regular without stochasticity and the connection length is sufficiently long for good divertor performance. Such a divertor configuration is produced in the magnetic field configuration for the CFQS device, which is now under construction in China. [ABSTRACT FROM AUTHOR]

The first time of flight diffractometer at the China Spallation Neutron Source (CSNS), General Purpose Powder Diffractometer (GPPD), has entered the user program in 2018. GPPD is a flexible and versatile instrument to study the crystallographic and magnetic structures of polycrystalline materials. After more than 3 years of debugging and operation, the high performance of the diffractometer has been achieved for a good instrumental resolution 0.15% and a wide d-space detection range 0.05–50.48 Å together with the desirable signal-to-noise ratio characteristics, enabling a large number of user experiments and achievements. The typical scientific applications of GPPD demonstrate its outstanding potential for unraveling the precise structure of crystals. [ABSTRACT FROM AUTHOR]

A maar-diatreme forms in response to the phreatomagmatic eruption caused by violent interaction between magma and externally derived water. Experimental work on phreatomagmatic eruptions has yielded considerable knowledge on maar-diatremes. However, the mechanism and process at natural scale remain poorly understood, especially when surface deposits are present. This paper presents a magnetotelluric and magnetic study of the Late-Pleistocene maar-diatreme volcanoes in the Lei-Hu-Ling area of northern Hainan Island, China. The regional 3D electrical structures show shallow high resistivities below craters and a low resistivity layer overlying the deep high-resistivity basement. The local magnetic structure of maar Luo-Jing-Pan reveals a cylinder-like diatreme with high susceptibility. The shallow low-resistivity zone, which coincides with the Fushan depression controlled by the Changliu-Xiangou Fault, is associated with the accumulation of high-salinity fluids with high porosity. The considerable volume of water stored in the Fushan depression and the sedimentary basement ridges beneath maars could have enabled a high level of magma-water interaction. This indicates a fault-controlled type for the phreatomagmatic eruption in the Lei-Hu-Ling volcanic area. The explosion depth is at least 600 m for Ru-Huang-Ling and Luo-Jing-Pan maar-diatreme volcanoes, indicating deep phreatomagmatic eruptions with less contribution to surface deposits. In addition, the explosion energy of the Ru-Huang-Ling maar with a diameter of 1900 m is about 7–8 times that of Luo-Jing-Pan maar with a diameter of 900 m. • Late-Pleistocene maar-diatremes of northern Hainan Island, China are delineated by a magnetotelluric and magnetic imaging. • Fushan depression provides a considerable volume of water for phreatomagmatic eruption. • The phreatomagmatic eruptions are of the fault-controlled type with explosion depth of at least 600 m. [ABSTRACT FROM AUTHOR]