Development Of Vertical Superconducting Magnetic Separator And Experimental Study On Pre-enrichment Of Rare Earth Tailings

China is rich in rare earth resources and ranks first in the world.The development of rare earth resources began in the 1980 s.Due to the disorderly mining of rare earth resources and the limitation of sorting technology,rare earth resources have not been effectively recovered,resulting in the loss of a large amount of rare earth resources in rare earth tailings and the occupation of rare earth tailings.A large amount of land resources and potential environmental pollution and safety problems.Due to the low REO content in rare earth tailings and the lack of REO sorting technology and equipment,REO recycling of rare earth tailings has not been industrialized.With the country's integration of rare earth resources,the implementation of planned mining and the continuous development of sorting technology,it provides technical support for the recycling of rare earth tailings REO from the aspects of technology and equipment.In order to protect the long-term effective development and utilization of strategic rare earth resources and ensure national strategic security,the rational development and utilization of REO in rare earth tailings has important resource,social,environmental and economic significance,and has important strategies for the sustainable development of rare earth resources.significance.REO magnetic pre-concentration of rare earth tailings is one of the effective preconditions for the reuse of rare earth tailings.The normal magnetic separator cannot effectively recover the fine-grained weak magnetic rare earth mineral or the coarse-grained rare earth mineral continuous body,and the large-scale heat is generated in the excitation process by the constant-conducting magnetic separator,which limits the performance of the equipment in terms of excitation current and energy consumption.In this paper,a new type of superconducting magnetic separation equipment is developed: JS-6.5-102 L vertical superconducting magnetic separator.The paper system clarifies the sorting cavity structure,magnetic system design parameters and magnetic magnetic medium design in the magnet design process;And the supporting design for reporting the stable operation of superconducting magnets,including: quench protection design,low temperature system design and monitoring system design;finally realize the complete assembly of vertical superconducting magnetic separator.When sorting by the magnetic separator,gravity is a kind of mechanical competitiveness,which contributes to the discharge of gangue minerals,and effectively avoids the blockage of materials in the horizontal magnetic separator medium.The magnetic separator can provide magnetic induction of up to 5.5 T,enabling efficient recovery of weak magnetic minerals.Under the premise of high magnetic field,the use of high flow rate can effectively reduce the inclusion of gangue minerals in the concentrate and achieve efficient enrichment of useful minerals.A vertical superconducting magnetic separator was used to sort the rare earth tailings in Liangshan area.The effective recovery of REO in rare earth tailings was achieved by optimizing the magnetic field strength,the ore flow rate,the ore concentration and the medium type.Under the conditions of feed particle size of-250?m,72.38% and TREO of 1.71%,after one rough selection,the refined product with a concentrate REO grade of 3.82% and a recovery rate of 83.15% was obtained.By comparing and comparing the sorting results of different magnetic separators,the sorting results of vertical superconducting magnetic separator are better than those of horizontal superconducting magnetic separator and constant conducting high gradient magnetic separator.The sorted products were analyzed and tested using standard Taylor screen,chemical analysis,XRD,VSM and SEM to investigate the performance of the vertical superconducting magnetic separator.The results show that coarse-grained gangue minerals and fine-grained useful minerals have been effectively recovered.A small amount of rare earth minerals that cannot be effectively recovered are mainly ultrafine rare earth single minerals and extremely rare earth rare earths.Further use ANSYS software and software simulation to calculate the magnetic field force and fluid viscous force of different granular grade mineral particles during the sorting process.The results show that the magnetic force required to recover fine-grained minerals is much larger than that of coarse-grained minerals.Only the high magnetic field provided by superconducting magnetic separator can achieve effective recovery of rare earth minerals.The use of superconducting magnetic separator to achieve pre-enrichment of REO in rare earth tailings can not only obtain a large amount of rare earth resources,but also reduce the accumulation of rare earth tailings and reduce the environmental pollution of rare earth tailings.The research results of this thesis will provide a new direction and ideas for the utilization of rare earth tailings,and provide theoretical and technical support for the application of superconducting magnetic separation technology in rare earth resources.