Considering the widespread use of industrial soils, especially kaolin and feldspar in tile and ceramic factories, the potential of these minerals for using in the Isfahan's industries is of great importance from the perspective of employment and economic development of the province. However, the presence of iron impurities in the extracted product of the mines has reduced the quality and whiteness of the soil, making their products unable to compete with high-quality products produced in other provinces. The purpose of this research is to remove iron impurities from the feldspar product of the Sepero mine. In this regard, the effect of leaching agent, pH, agitation rate, time, particle size, temperature, acid concentration and pulp density were investigated. Oxalic acid was selected as the leaching agent and experiments were carried out at pH = 2. In order to determine the optimal conditions, response surface methodology (CCD) was applied. Optimum conditions were obtained at pulp density of 5%, 20 g/l oxalic acid, 70 °C, and leaching time of 90 minutes which removed 85% of the iron content of the clay. The kinetics of the experiment was investigated at 40, 60, and 80°C temperatures, and showed a reasonable match with the shrinking core model. This model indicated that the process followed the mixed mechanism control model. The highest iron removal occurred at 80°C and the activation energy was calculated as 61.68 kJ / mol. Two and three stage leaching experiments were performed at 5, 10, 15, 20 and 25% pulp densities, and improved the iron removal efficiency. Also, more leaching experiments were carried out in a stirrer reactor at a similar pulp densities that showed a positive effect on high pulp densities. The results of this study showed that the use of oxalic acid for removing iron from feldspar is a relatively efficient method.