Granulation Effectiveness of Iron Ore Sinter Feeds: Effect of Ore Properties

Abstract

This paper developed a quantitative understanding of the effect of ore properties on granulation effectiveness for different iron ore types based on the mechanistic model proposed by J.D. Litster et al. The granulation effectiveness was measured by the magnitude of x 0.5 , which was postulated to be a function of the layer binding strength. Water was adopted as the only binder for all granulation tests. A wide range of moisture contents, up to the optimum moisture content that yielded an optimum permeability, was tested for each ore type. The typical structure of granules made from different ores was investigated to reveal the effect of mineralogical properties of ore particles on the growth of granules. The results indicate that the granulation effectiveness x 0.5 varies markedly with ore type and moisture content. Feed particle size distribution and moisture for granulation are paramount factors determining the granulation effectiveness x 0.5 , which has a single relationship with the mass mean size of layering particles independent of ore type. The mass mean size of layering particles is dependent on the inherent size distribution of raw materials and the mass fraction of layering particles, while the latter is linear to available moisture content. The model works well for some ore types except for those with unreasonable size distributions: 1) excessive intermediate particles meanwhile lacking of fine particles; or 2) excessive ultrafine particles. An effective criteria closely related to layer binding strength, (1 − ε)S/ε d , is proposed to determine the applicability of the model.

Determining Optimum Water Content for Iron Ore Granulation using Agitation Torque of Wet Ore Powder

“…3) Therefore, the handling of fine ore powder is a critical issue in the ironmaking process. [4][5][6][7] In the manufacturing process of pig iron, wet granulation has often been performed prior to the sintering process to reduce fine ore particles. In the wet granulation process, the fine ore particles are agglomerated with coarse ore particles by adding water to agitated particles in a granulator, such as a drum mixer.…”

Significant influence of self-possessed moisture of limonitic nickel laterite on sintering performance and its action mechanism

“…In the granulation process, sinter mixture particles are made into the granules with appropriate moisture and reasonable size distributions during rolling, which is mainly dominated by the action of capillary force formed between water and sinter mixture particles [28,29]. Capillary water plays a key role in granulating and its migration rate determines the pelletizing efficiency of sinter mixture.…”

Taguchi Orthogonal Test on Granule Properties and Porosity Distribution in Sintering Bed using High-resolution X-ray Computed Tomography

“…This conclusion is consistent with open literature that water addition leads to the larger granule size and narrower size distribution. [7][8][9]14,18,19,25) The granule morphologies under different moisture conditions are presented in Fig. 5, it can be found visually that when moisture is as low as 5.8%, there are few fine powders adhered to the granule surfaces, and granule size is small.…”

“…5,6) Reportedly, moisture available for granulation is the paramount factor to determine the granule growth mechanism and further greatly affect granulation effectiveness. 7) It is considered that the addition of water increases the granule mean size and tightens the size distribution, as well as greatly influences the packed bed porosity due to the wet granules deformation. 2,8,9) Besides, the inherent physicochemical properties of feed components such as size distribution, density, granule shape, surface characteristics as well as moisture capacity [10][11][12][13] also contribute to the granule packed bed properties.…”