The adsorbent is continuously washed by a flow of solvent (moving phase) passing through column. Initially, the components of the mixture adsorb onto the solid phase at the top of the column. The continuous flow of solvent through the column elutes, or washes, the solutes off adsorbent and sweeps them down the column. The solutes are called eluates or elutants, and the solvents are called eluents. As the solutes pass down the column to fresh adsorbent, new equilibria are established among the adsorbent, the solutes, and the solvent. The constant equilibration means that different compounds will move down at differing rates depending on their relative affinity for the adsorbent on the one hand, and for the solvent on the other. Because the number of alumina particles is large, because they are closely packed, and because fresh solvent is being added continuously, the number of equilibrations between adsorbent and solvent that the solutes experience is enormous.