Development of Pellet-Sinter Composite Agglomerate for Blast Furnace

Abstract

Microfines of iron ore are generally utilized in Blast furnace in form of indurated pellets because sinter bed has limitation of accepting fines. Charging of acid pellets with basic sinter is the normal practice in blast furnace. However induration of pellets is very cost intensive. Further more, due to low angle of repose pellets distribution during charging with other materials in blast furnace creates inhomogeneous distribution. In order to alleviate the above problem, a composite mass of acid pellet and basic sinter has been developed, wherein; green pellets made-up of microfines were mixed with basic sinter mix and sintered the combined mass in a sinter bed of 10-12 kg scale. A composite mass of indurated pellet and sinter named as 'Pellet-Sinter Composite Agglomerate' was obtained. Linz Donawitz converter sludge and mill scale were used in pellet mix to provide in-situ heat in pellets that enhances incipient fusion to form bond in pellets. The developed sinter shows good shatter index (92%), tumbler index (67.5%) abrasion index (7.5%) and reducibility index (70%) and low reduction degradation index (27%), which are comparable with the conventional iron ore sinter made in the same set-up keeping other condition identical. This innovative technique help improving 30% microfines utilization in sinter bed, reduce coke breeze/energy consumption, reduce overall basicity of sinter and decrease flux composition.

Development of hematite ore pellet utilizing mill scale and iron ore slime combination as additive

“…Since mill scale is a source of magnetite in a pellet, it may improve the strength of pellet. Pal et al [14] used mill scale as in-situ heat source in their Pellet-Sinter Composite Agglomerates (P-SCA) and found a good strength improvement. Rajshekar et al [15] found a better sintering property by using mill scale in hematite ore than by using pure hematite ore.…”

Mill scale as a potential additive to improve the quality of hematite ore pellet

“…Moreover, highly fluxed pellet reduces the basic sinter acceptance capacity of blast furnace. Acidic hematite pellet is advantageous because blast furnace can accept more basic sinter and replace lump ore charging Pal et al 2014aPal et al , 2014b Magnetite is an inverse spinel structure with the oxygen ions forming an ABCABC layered packing. The Fe 2+ occupies the octahedral sites in between the oxygen atoms and Fe 3+ occupies both tetrahedral and octahedral sites.…”

“…However, use of mill scale in pellet is also an important aspect. Pal et al (2014b) used mill scale as in situ heat source in their Pellet-Sinter Composite Agglomerates (PSCA) and found good strength improvement. Ahmed et al (1997) observed low drop numbers in complete mill scale pellets which was increased with the addition of lime as binder.…”

Preparation of BF Burden from Titanomagnetite Concentrate by Composite Agglomeration Process (CAP)

“…It is worthy to be mentioned, the investigators 28) comment that some separate pellets in agglomeration product and the strength of those pellets is the key factor of sinter quality. In fact, their understanding is inaccurate for blinding to the pelletized feed is embedded into the matrix part in CAP product.…”

“…Consequently, it is proved that CAP is an effective and efficient for titanomagnetite concentrate agglomeration, in terms of productivity, energy consumption and CO 2 emission. 28) b) Agglomeration Products Properties Table 7 shows the main properties of products from CAP and TSP. The tumbler index increases by 13.08%.…”