Computer simulation of the preparation process loading rare earth(RE)directly from acidic extractant and RE chloride was established using MATLAB software.The mechanism of the extraction reaction was assumed,and then an experiment was conducted to confirm the mechanism and the apparent equilibrium constant of the reaction was determined as well.Owing to the involvement of H+ ion in the reaction between acidic extractant and RE chloride,the computer simulation of the process was more complicated than that of the extraction only between different rare earths.In the present work,MATLAB software was therefore introduced to handle the resolution of the complicated processing equation,and the simulation was performed by varying some key parameters including feed composition and phase ratio,etc.Consequently this work presented a simple method to simulate the H+ ion involved countercurrent extraction process of rare earths and also provided the practical references for the relative process designing. Computer simulation of the preparation process loading rare earth (RE) directly from acidic extractant and RE chloride was established using MATLAB software. The mechanism of the extraction reaction was assumed, and then an experiment was conducted to confirm the mechanism and the apparent equilibrium constant of the reaction was determined as well. Orwing to the involvement of H + ion in the reaction between acidic extractant and RE chloride, the computer simulation of the process was more complicated than that of the of the extraction only between different rare earths.In the present work, MATLAB software was therefore introduced to handle the resolution of the complicated processing equation, and the simulation was performed by varying some key parameters including feed composition and phase ratio, etc., governing this work presented a simple method to simulating the H + ion involved countercurrent extraction process of rare earths and also provide the practical references for the relative process des igning.