The collision interaction between particles and air bubbles in the flotation pulp phase has been analyzed. The inertial effects on the particle-bubble collision probability are ignored (inertialess model). Special attention has been paid to the influence of a swarm of bubbles on the water velocity near the bubble surface. The approximation for water radial velocity near the bubble surface permits derivation of an expression for both collision probability and collision angle as a function, besides others, of gas holdup. This provides useful information for further understanding the particle collection (collision, sliding and adhesion) process in flotation. The model is for gas holdup in the range 0 less-than-or-equal-to epsilon less-than-or-equal-to 0.30, for bubble Reynolds number up to 500 and for a ratio of particle size to bubble size D(p)/D(b) much less than 1.