Improvement of Permeability of Sintering Bed by Adding Dry Particles to Granulated Raw Materials

Abstract

In order to increase the permeability of the sintering bed for sinter ore productivity, RF-MEBIOS (Return Fine -Mosaic Embedding Iron Ore Sintering) process, in which return fine as dry particle is added to granulated raw materials and then they are charged into a sintering machine, is proposed.In this paper, the pot suction tests and the direct shear tests were carried out to confirm the reason of increasing permeability of the sintering bed by addition of dry particle. As a result, it is proven that the increasing of permeability is caused by two major phenomena. One is by increasing the pseudo-particle size at granulation and the other is by decreasing the bulk density of the sintering bed after charging. The former is achieved by higher moisture content in the raw materials at granulation. The latter is achieved by higher friction in the packed bed composed of dry and wet particle compounds. Therefore, the voids are easy to remain in the sintering bed when the materials are charged into the sinter machine. The influence of the dry particle brand on permeability is not so strong, but larger dry particles make the permeability higher. Also, when the wet particles are added after granulation, the permeability decreased at the same moisture content condition of the packed bed.

Improvement of Sinter Productivity by Adding Return Fine on Raw Materials after Granulation Stage

“…In addition, the bulk density is decreased by dry return fine addition into granulated wet particles. 18) Both the decrease of pseudo-particle size (-0.25 mm) ratio at charging and the decrease of the bulk density contributes to improving productivity.…”

Numerical Simulation of Particle Mixing Behavior in High Speed Shear Mixer and Cylinder Mixer

“…The tangential rolling friction is expressed by applying a torque to the contacting surfaces, as shown in Eq. (13). Where δ t and u t rel are the tangential overlap and the tangential component of relative particle velocity.…”

“…12) However, the quasi-particles produced by the traditional cylinder mixer under heavy load are with some disadvantages such as uneven size distribution and serious component segregation. 13,14) It not only greatly reduces the efficiency of mixing and granulating process, but also reduces the service life by forming a thick inner ring made of the lime and water in the drum. 7,[15][16][17] It is well known that mixing and granulation can achieve easily under the heavy loading in a horizontal high shear mixer which is widely used in the pharmaceutical, food, agriculture and chemical industries.…”

Effect of Drying Treatment after Granulating Sinter Raw Materials on Flame Front Speed and Sintering Yield

“…When introducing the process, mixer specifications has also examined for determination of essential mechanical parameters, for example angle size and rotation speed. 8) The typical applications for utilization of granulating binder as moisture and quick lime are Technique of adding dry return fine on raw materials after granulation stage 16,17) and of Anionic polymer dispersant (APD) utilization at sinter material granulation. 18) Philosophy of the former is promoting granulation caused by increasing moisture content at granulation stage through bypassing dry return fine.…”