Evolution Law Of Ionic Rare Earth In Situ Leaching Ore Wetter And Prediction Model Of Blind Area

The ionic rare earth mine in Gannan is mined by in situ leaching process.Although the in situ leaching process has many advantages,it has been promoted for many years,but also reveals many shortcomings,such as: the arrangement of hole network(well)parameters mainly rely on experience,etc.,which has serious impact on rare earth resource recovery.This paper takes a rare earth mine in Dingnan as the research object,and simulates the in situ leaching process of ionic rare earth ore through indoor experiments to study its wetted body evolution law;uses HYDRUS-2D to simulate the wetted body evolution law of ionic rare earth in situ leaching to reflect the change of blind area and verify its applicability;analyzes the influence of different influencing factors index on the blind area of ionic rare earth in situ leaching,and uses SPSS software optimization;establish the prediction model of blind area of ionic rare earth in situ leaching and evaluate it by using the measured values.The work and results of this paper are as follows:(1)The shape of the wetted body generally follows the rule of "vertical downward >horizontal > vertical upward",and it is found that the leaching blind area appears above the wetted body;for the changing trend of the wetted front of the wetted body,it is found that the power function can describe the changing law of the wetted front displacement more accurately;the Kostiakov model can be used to describe the rate of wetted front The relationship between transport rate and infiltration time can be described by the Kostiakov model;in the first stage of infiltration,the wetted surface area of the wetted body basically increases with time as a power function,and in the second stage of infiltration,the growth rate of the wetted surface area gradually slows down and finally reaches a relatively stable state;from the early stage of infiltration to the second stage of infiltration,the cumulative infiltration volume is almost linearly related to the infiltration time,and after the second stage of infiltration,the cumulative infiltration volume increases with the infiltration After the second stage of infiltration,the cumulative infiltration volume decreases with the infiltration time and finally stabilizes;four different hole spacings were used for the indoor experiments,and the blind area of the leaching zone was the smallest at a hole spacing of 24 cm.(2)Based on Richards’ equation,a water movement model of ionic rare earth in situ leaching wet body was established and solved by HYDRUS-2D software.The statistical characteristics of the simulated and measured values of ionic rare earth in situ leach blind area were analyzed and found to be in good agreement,indicating that it is feasible to use HYDRUS-2D to simulate the moisture movement of ionic rare earth in situ leach wet body,and the proposed mathematical model and solution method are effective.(3)HYDRUS-2D is used to simulate the evolution of ionic rare-earth in situ leach wetted body under the factors of pore spacing,pressure head,pore diameter and matrix potential to reflect the changes of blind area.Using hybrid orthogonal experiments,the factors affecting the blind zone area of ionic rare earth in situ leach were obtained in the following order: pore spacing,pressure head,pore diameter and matrix potential.The optimized optimal combination of parameters was hole spacing L = 24 cm,pressure head H = 25 cm,hole diameter B = 2.0 cm,and matrix potential =-300 cm.(4)Based on the simulated data,the blind area variation of ionic rare earth in situ leaching under pressure head,pore size and matrix potential is transformed into a mathematical problem for solving and analyzing,and the blind area prediction model of ionic rare earth in situ leaching is established,and the blind area prediction model of ionic rare earth in situ leaching under pressure head is verified by indoor experiments.By analyzing the statistical analysis indexes between the indoor measured values and the model calculated values,it is found that there is no significant difference between them,indicating that it is feasible to predict the blind area of ionic rare earth in-situ leaching using this model.It can provide a basis for the calculation of the blind area of ionic rare earth in-situ leaching,and then provide a reference for the optimization of ionic rare earth hole network(well)arrangement.