Cold bonded pelletization of iron ore fines using ordinary portland cement binder is emerging as a potential energy saving agglomeration process for proper utilization of Indian iron ore fines. The possibility of substituting ordinary portland cement/clinker by cheaper low grade Indian granulated blast furnace slag is investigated. The strength development characteristics of pellets containing slag-clinker is similar to those containing clinker as the binder. Around 50% of the ordinary portland cement required for making pellets of desired properties can be stubstituted by slag. The crushing strength of the pellets is found to increase with increase of diameter of the pellets. The green pellets on normal curing for 5–7 days develop crushing strength of 60–90 kg/pellet which enhances to 125–175 kg/pellet or 140–220 kg/pellet, respectively on prolonging the normal curing to 28 days or subjecting to heat/steam treatment for a few hours. Slag-clinker containing pellets are slightly less basic but are more reducible than those of clinker containing pellets.