| Centrifugal concentrator is a kind of concentrating equipment that can make mineral particles obtain several or even hundreds of times of gravity acceleration by centrifugal force,thus enlarging the specific gravity difference between light and heavy part icles,and separating the mineral particles with different densities.This kind of equipment has the advantages of large throughput,low cost and environmental friendliness,and is widely used in major mineral processing plants.However,the traditional centrifugal concentrator is mostly used in the separation of high density minerals,and the separation performance of minerals with small density difference between valuable components of tailings and gangue is poor.In order to solve this problem,this paper takes STLB20 centrifugal concentrator as the prototype and studies the selective separation law of light and heavy particles under the coupling action of centrifugal force and backwash water pressure from the angle of micro-particle interaction.The separation process is simulated by CFD simulation software FLUENT,and the effects of different process parameters and structural parameters on separation performance are studied.The equipment structure is optimized and simulated to explore the separation and recovery technology suitable for valuable components of tailings particles.The research work of this paper includes the following contents:(1)The principle of high gravity separation and the working process of high gravity separation equipment are studied.The force of mineral particles in the flow field is analyzed,and the dynamic model of high gravity separation is established.The movement law of particles with different densities in radial,axial and tangential directions and the influence of particle accumulation on the separation degree are clarified.The relationship between the final velocity of particle radial settlement and the particle state is analyzed.The effects of backwash water pressure,supergravity strength,feed rate and slurry concentration on particle separation were studied.(2)The finite element model of two-component particles under the coupling action of hypergravity two-way medium is established,and the distributions of pressure,radial velocity,axial velocity and tangential velocity of particles in the flow field are studied by FLUENT simulation,and the movement and volume concentration distribution of light and heavy particles in the separation process are revealed from the microscopic point of view.(3)The influence of separation cone speed and backflushing water pressure on particle separation performance was studied.It was found that with the increase of separation cone speed and backflushing water pressure,the rate of recovery of heavy particles in concentrate increased first and then decreased,which indicated that better separation effect could be obtained by reasonable matching of specific separation parameters.(4)By analyzing the movement and distribution of particles with different densities,the structure of enrichment tank and reverse fluidization was optimized,and the effectiveness of the structural improvement was verified by simulation.The simulation results show that the improved trapezoidal enrichment tank and annular slot reverse fluidization structure can significantly improve the separation of two components with a low density difference.The research in this paper can obtain high efficient separation of multi-density particles under high gravity environment,enrich the methods and practices of mineral processing,provide a good reference for the reuse technology of tailings in China,and have broad application prospects. |
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