Abstract:Address to long leaching cycle, high leaching agent dosage, and rare earth tailing in the leaching process of weathered crust drenching rare earth ore, the leaching process of rare earth was investigated by using non-ionic surfactant as leaching aid and magnesium chloride as leaching agent. The properties of compound leaching agent solution was studied, the particle size distribution of minerals before and after leaching was analyzed, and the mechanism of surfactant to promote percolation was explored. The results show that the addition of surfactant increases the leaching rate of rare earths, accelerates the permeation rate, reduces the surface tension and contact angle of the solution, increases the viscosity, significantly reduces the median particle size of the mineral particles, and increases the Zeta potential of the mineral surface. The addition of Tween 40 improves the leaching rate of rare earths to 86.38%, reduces the surface tension by 19.00%, reduces the contact angle by 53.19%, and reduces the solution viscosity by 4.29%, which the solution properties changes the most. The results show that the addition of surfactant can make the solution wet the minerals more easily, the resistance to enter the pore space becomes smaller, the thickness of the diffusion layer is reduced, and the swelling of clay minerals is inhibited, which makes the solution leaching rare earths better, among which Tween 40 has the greatest effect on the solution leaching rare earths percolation effect and the best percolation aid.