Binding force in the form of spring force binds two adjacent spherical grains and based on this interaction various
structures of composite particles can be constructed. In this work only composite particles up to N = 4 are discussed, where
N is number of spherical grains in a composite particle, and the forms are limited to the two-dimensional cases only. There
is only one structure of composite particle for each value of N for 1 < N ≤ 2. For N = 3 there are five structures and for N =
4 there are fifteen structures. Between spherical grains from different composite particles only two types of force are
considered. The first is a long-range attractive force in the form of gravitation force and the last is a short-range repulsion
force in the form of normal force. The first type of force will help the aggregation process, while the second will prevent
two spherical grains to collapse into a single grain due to the first. It is observed that the time required to produce the
compact aggregate or T is dependent on N, where larger N makes larger T.