Evaluation Of The Applicability Of Ion-adsorption Rare Earth Leaching And In-situ Leaching

With the development of society,the value of rare earth elements has received more and more attention,especially in the field of high technology and industry,where the addition of a little rare earth element usually results in a great change in the performance of the relevant materials.China’s rich reserves of rare earth resources are widely distributed,and the control and research of rare earths can improve China’s voice in the rare earth industry and further improve the country’s social status,so it is important to study the mining methods for rare earth resources.Research work has been carried out at home and abroad for many years,while further research is needed on issues such as the applicability of in situ leaching processes.In this paper,the leaching efficiency of rare earths is investigated through indoor tests and numerical simulations,taking into account the leaching conditions under different working conditions.The in situ leaching process was evaluated by AHP-Fuzzy Mathematics and the main conclusions were obtained as follows:(1)Indoor geotechnical tests were carried out,particle analysis tests,specific gravity tests and permeability tests were carried out to obtain relevant parameters of ionic rare earths(gradation of particles,specific gravity of soil particles,permeability coefficient),which provided the basis for subsequent indoor column leaching tests and numerical simulations.(2)Indoor column leaching tests were carried out on rare earth particles in unscreened condition.The relationship between different leaching agent types,different leaching agent concentrations,different liquid to solid ratios and different raw ore moisture contents on the leaching process and efficiency of rare earths in relation to the amount of effluent was investigated,and methods to improve the leaching efficiency of rare earths were optimised.(3)Based on the finite element method,the relevant model is established by COMSOL software,considering the leaching of rare earths as an unsaturated process,and the physical field equations of the coupled percolation-chemistry-mass transfer multifield are established by numerical simulation to study the leaching of rare earth ions at different concentrations,and the results show that the reliability of the numerical model is verified by comparison with indoor tests.(4)An in situ leaching suitability index system is established based on AHP-fuzzy mathematics,which integrates quantitative and qualitative factors to establish an evaluation index system that comprehensively reflects the in situ leaching situation,yielding an affiliation degree of 0.692 for the suitability grade of the case mine.By the principle of maximum affiliation,it is known that the model and the actual mining situation are consistent,thus verifying the reasonableness of the in situ leaching suitability evaluation system.