For the purpose of developing a process in which the cold pellet can be produced in about 10 hours, the continuous rapid curing procedure has been investigated using iron ore pellet with 10%-portland cement and dust pellet with 14%-B.F. granulated slag as binder.
1) A continuous curing with about 10 hours is possible by the combination of pre-drying, steaming below 100°C and drying.
2) The strength of pellet using portland cement is improved in drying with atmosphere.
3) In the operation of pilot plant with 6.5 ton/day, the compressive strength of produced ore pellet and dust pellet are 170-200kg p and 140-170kg/ p respectively, and their physical properties are comparable to that of fired pellet.
4) The required energy of this process is about 80 000kcal t product, and this process is a polution-free and energy saving process in which the waste gas from the plant can be used.
5) The hydrates of cement are decomposed in 800-900°C, however, the shape and strength of pellet are remained by sintering between ore and cement particles. Above 1 000°C the coherence of pellet is reinforced. This phenomena agree with the behavior of swelling and strength of pellet during reduction.
