A numerical study has been made for a two-dimensional, laminar, incompressible flow with SPM past a vertical plate. The governing equations are solved by an implicit finite difference technique using non-uniform grid to investigate the effect of buoyancy force and the dimensionless parameters like volume fraction (j), Nusselt number (Nu), Prandtl number (Pr), concentration parameter (a), and diffusion parameter (e) over thermal boundary layer characteristics. The density, and temperature profiles as well as the displacement thickness, skin friction coefficients, and the heat transfer for both the fluid and particle phases are represented and discussed through graphs and tables. It has been observed that heat flows from the plate towards the fluid as Nusselt number (Nu) is positive. Presence of more number of particles in the carrier fluid decreases the velocity of both fluid and particle velocity. Temperature of carrier fluid and particles remains unaffected irrespective of particle material density but temperature of particle phase increases due to presence of SPM of heavier materials. Increase in diffusion of particles through carrier fluid does not affect the fluid flow but helps in faster movement of the particles through carrier fluid and increase in particle phase temperature. Further, it has been observed that temperature falls more rapidly for air than water and electrolyte as carrier fluid. Coarser particles help in heat transfer from plate to fluid and reduction of skin friction and decrease in displacement thickness.