Study On The Influence Of Main Structure And Process Parameters Of Spiral Concentrator On Sorting Flow Pattern And Fluid Stability

Spiral concentrator is a kind of gravity separation equipment,which is widely used in industry due to its advantages of low energy consumption,no pollution,easy configuration,and easy realization of scale production,and is a key beneficiation equipment for iron,titanium,tin,chromium and other ores.In this paper,we investigate the wave phenomenon on the surface of spiral sorting fluid observed in the production practice of spiral concentrator,construct the CFD model of spiral concentrator,investigate with the help of hydrodynamic rolling wave theory,find out the influence law of main structure and process parameters of spiral concentrator on the sorting flow pattern and fluid stability,and propose the strategy of regulating the stability of spiral sorting fluid,and finally investigate the CFD model and fluid stability by laboratory experiment.Finally,the CFD model and fluid stability findings were verified by laboratory experiments.The relationship between the pulp flow rate and the structure and process parameters of the spiral concentrator was theoretically deduced from the separation principle of the spiral concentrator,and the evolution of the wave phenomenon of the spiral sorting fluid and the influence of the structure and process parameters on the evolution of the wave were analyzed and studied with the help of the hydrodynamic wave theory.The CFD technology is used to construct a model of spiral concentrator sorting flow field,and the model is used to study the influence of structure and process parameters on the flow pattern of spiral concentrator sorting fluid.The results show that the flow velocity of the spiral concentrator sorting fluid shows a trend of increasing and then decreasing in the radial direction,and the depth of the flow is characterized by a thin inner center and a thick outer edge.The flow velocity increases with the increase of diameter,pitch ratio and feed flow rate,and decreases with the increase of fluid viscosity;the flow depth of fluid in the spiral concentrator increases with the increase of diameter,pitch ratio and fluid viscosity,and decreases with the increase of pitch ratio;the Reynolds number value of water flow at the outer edge of spiral sorting fluid increases with the increase of spiral concentrator diameter,and the proportion of laminar flow of spiral sorting fluid decreases.After simplifying the fluid partitioning in the spiral trough,the stability of the fluid in the spiral trough is studied with the help of the established CFD model and the existing hydrodynamic rolling wave theory.The stability of the fluid in the spiral concentrator decreases by 14% and 25% when the distance-to-diameter ratio increases from 0.45 to 0.54 and 0.6,respectively;for a certain spiral concentrator,there is a specific value of the incoming flow rate at which the stability of the fluid in the concentrator is lowest,and the stability of the fluid in the concentrator increases above or below this flow rate;the stability of the fluid in the spiral concentrator increases with the increase of the fluid viscosity.With the help of gray correlation analysis,the influence of each structure and process parameter on the fluid stability is studied,and the results show that the spiral groove diameter has the greatest influence on the fluid stability.Based on the above results,the stability control strategy of the spiral concentrator is proposed,and the spiral concentrator with small diameter and small pitch ratio is preferred for the separation of minerals with fine grain size and small specific gravity,while the spiral concentrator with large diameter and large pitch ratio can be used.With the help of the spiral concentrator sorting system built in the laboratory for flow and stability testing experiments,the experimental results and simulation results are basically consistent,proving the credibility of the CFD model and fluid stability study results constructed in this paper.The findings of this paper are of some significance for the selection of industrial spiral concentrators,process optimization and development of new spiral concentrators.