Study on the Effect of Coal Gangue Particle Size Distribution for the Preparation of Kaolin by Shaking Table Separation

The presence of pyrite in coal gangue significantly degrades the performance of its prepared kaolin in ceramic and coating applications. Implementing separation techniques to remove pyrite can markedly enhance the quality of kaolin products. However, there is no research on the effect of material particle size distribution on the separation effect in the current study on shaking table separation. For this reason, the coal gangue was crushed to different maximum particle sizes in this study, and its particle size distribution was fitted and analyzed. Based on the fitting results, the Rosin–Rammler–Sperling–Bennet (RRSB) distribution with a uniformity coefficient n of 0.74 was used to study the influence of the characteristic particle size de on the separation effect. Fuller distribution with distribution modulus q of 0.45 was also used to study the impact of maximum particle size dmax. The results showed that the Fuller distribution reduced the contents of SO3 and Fe2O3 by 30.85% and 25.71%, respectively, compared with the raw materials. In comparison, the RRSB distribution reduced the contents of SO3 and Fe2O3 by 41.01% and 30.85%, respectively, indicating that the separation effect of the RRSB distribution was better than that of the Fuller distribution. In addition, when the characteristic particle size de of the RRSB distribution was 37–42 μm, the content of SO3 and Fe2O3 in the tailings varied very little, and the separation effect was stable. This study demonstrates that the particle size distribution significantly influences the separation efficiency of the shaking table, providing a novel idea for enhancing shaking table separation processes. Future studies may further explore the effect of another parameter or two-parameter coupling of RRSB distribution and Fuller distribution on the separation effect of the shaking table.