# Simulation Analysis of Cyclone Separator for Separation of Cenospheres
## 1 Introduction
The spherical and hollow structure, chemical composition, and mechanical and energy dissipation properties of these cenospheres allow them to be fused with conventional cements to form lightweight workable materials with closed pores, which are particularly suitable for bridge decks, sidewalks, and highways where durability is required. The application of porous nanospheres as an internal curing agent is able to absorb and retain up to 180 wt% of water, which is slowly released in the silicate cementitious matrix, effectively controlling autogenous shrinkage. In addition, cenospheres can be used in noise barriers and asphalt concrete matrices to provide excellent sound damping and freeze-thaw resistance. Their lightweight properties also help to simplify the installation process, thereby maximizing cost-effectiveness. These properties make cenospheres an important application and potential development for modern building technology [22; 23]. The separation of hollow beads has two methods: dry separation and wet separation. The most commonly used method for industrial separation of hollow beads from fly ash is wet separation, where floating particles in the ash ponds or lagoons are separated into hollow beads; the density of the hollow beads collected by this method is less than 1.0 g/cc [24; 25; 26; 27]. Most of the separations described in the present literature are achieved by wet separation processes, which are generally carried out using water or other solutions as the medium for separation, and the efficiency of the wet separation depends on a number of factors, such as the density difference and buoyancy between the solid particles and selected solution; the concentration of the feed particles; the smoothness of the particle surfaces; and the recycling of the solution [1]. [PERSON] utilized acetone solution for the wet separation of cenospheres and analyzed the effect of different concentrations of acetone solution on the separation efficiency, recovery, and quality produced by the cenospheres microspheres [28]. To some extent, wet separation may pollute the environment, as the current technology of wet separation consumes large amounts of water and leads to water pollution and soil contamination due to the leaching of toxic substances from fly ash, especially in countries with limited living space [29]. A further disadvantage may be the accumulation of fly ash particles on the buoyant surface, which restricts the sinking of the solid particles in the C and F fly ash, leading to an increase in impurities in the cenospheres product. In addition, Ca(OH)\({}_{2}\) crystallization can form on the surface of the hollow beads when the calcium content of the fly ash is high. These crystals harden during the drying process of the nanospheres, thus limiting their further application [2]. The wet separation process has many unavoidable shortcomings, so the study of dry separation is particularly important. Dry separation can keep the chemical composition of the particles unchanged and avoid water pollution and energy consumption caused by drying, and the required technical equipment occupies less space compared with wet separation. One of the applied technologies is the air classifier, which is a unit operation technology that utilizes the geometric or hydrodynamic/aerodynamic equivalent diameter of the particles as well as density differences for solid particle separation. The technology consists of five classifier types: gravity, cascade, fluidized bed, inertial, and centrifugal. The classifiers designed for micron-sized particle separation are the inertial and centrifugal classifiers, while the other types are suitable for millimeter-sized particle separation. The separation process is based on the particles being suspended in a gas stream and subjected to gravity and having drag forces acting in opposite directions.