An estimation method for spatial permeability distribution of the ion-adsorption type rare earth ore body

Permeability of ion-adsorption rare earth ore body is an important factor in the consumption of leaching agent and leaching rate. Reasonable determination of its spatial distribution is the key to mining design. For deeply buried ore body, there are large errors in the existing determination methods of permeability coefficient. In this paper, a certain ion-adsorption rare earth ore body was selected as the research object, and the permeability coefficients of rare earth ore (soil) under different particle gradations and different void ratios were analyzed. The d₁₀, uneven coefficient and void ratio were linear with the logarithm of permeability coefficient. The coefficient of variation of each parameter to slope was less than 20.0%, indicating that these three parameters were linearly correlated with each other. Then the calculation model of permeability coefficient was established, namely, k=10^{5.16e+240.97d₁₀+9.72×10-3C_u-10.51}. Compared with the experimental data, the average relative error of the estimated permeability coefficient of the whole ore body was 15.1%, and the correlation coefficient was 0.986, indicating that the established model was reasonable. Combined with the ordinary Kriging method, the calculation method of spatial distribution of permeability coefficient of ore body was established, and the influence of variation function on the calculation results was analyzed. The results showed that the spherical model had the highest accuracy, and the determination coefficient and range of the variation function were 0.931 and 30.03 (m), respectively. This study provides technical support for the precise mining of ionic rare earth ore body.