Optimizing Dry Beneficiation of Palygorskite Through Air Classification for Improved Grade and Recovery

Palygorskite (PAL), also known as attapulgite, is a clay mineral prized for its nanorod-like silicate structure and fibrous morphology. The traditional PAL purification methods often involve wet gravity separation techniques such as sedimentation and screening, which require significant water usage and pose sustainability challenges, especially in the water-scarce regions. This work introduces a novel, environmentally sustainable dry beneficiation method for PAL. A large PAL sample with 41.7% content and 10% moisture was crushed, ground using a pin mill, and classified into three particle size fractions:-0.088 mm + 0.066 mm, -0.066mm +0.044 mm, and -0.044 mm. These fractions were treated with an air classifier. A Box-Behnken experimental design was employed to investigate the effects of particle size, shutter opening, and motor speed on the classification efficiency. The optimal parameters for grade were 400 rpm motor speed, shutter opening of 1 mm, and feed size of -0.066 mm + 0.044 mm. For the recovery, the optimal conditions were 1200 rpm motor speed, shutter opening of 2.5 mm, and feed size of -0.044 mm. The most favorable balance of grade (67.8%) and recovery (53.2%) was achieved with a motor speed of 1200 rpm, shutter opening of 4 mm, and feed size of -0.066 mm + 0.044 mm. The work concludes that air classification significantly enhances the PAL beneficiation process, with a 50% increase in grade, and recommends exploring the low shear grinding techniques for further improvement.

کلیدواژه های Optimizing Dry Beneficiation of Palygorskite Through Air Classification for Improved Grade and Recovery:

Palygorskite ، Clay Mineral Processing ، Air Classification ، Sustainable Separation Techniques